Highly Pathogenic Avian Influenza (HPAI) H5N1: Early Warning
PHC is tracking the evolution of highly pathogenic avian influenza (HPAI) H5N1 2.3.4.4b strain to provide early warning to PHC’s partners. Currently, the risk of person-to-person transmission of H5N1 is low, although as H5N1 expands into new animal reservoirs, this may change quickly.
As time passes, the risk of mutations that increase its severity or allow transmission between people increases — as does the risk of a pandemic.
Expert Insights
For information only. The establishment of broader milk testing and information collection will clarify the extent of H5N1 infection in dairy cattle nationally. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees....SEE MORE
For information only. The establishment of broader milk testing and information collection will clarify the extent of H5N1 infection in dairy cattle nationally. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees.
As part of its National Milk Testing Strategy, USDA issued a new Federal Order requiring that raw milk samples nationwide be collected and shared with USDA for testing upon request. The order also requires herd owners with positive cattle provide information that supports contact tracing and disease surveillance. [Confidence: Very High]
SHOW LESSBusinesses and individuals should dispose of any affected products. H5N1 avian flu and other pathogens have been found in raw milk. Pasteurization inactivates H5N1, making pasteurized milk and milk products safe to consume....SEE MORE
Businesses and individuals should dispose of any affected products. H5N1 avian flu and other pathogens have been found in raw milk. Pasteurization inactivates H5N1, making pasteurized milk and milk products safe to consume.
California has again expanded the recall of raw milk-related items from Raw Farm of Fresno County. Raw Farm milk products have tested positive for avian influenza at retail and dairy storage and bottling sites. The affected lot numbers are 20241109 through 20241127. No illnesses have been identified tied to the contaminated product. [Confidence: Very High]
SHOW LESSCalifornia's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been identified. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
California's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been identified. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California has confirmed H5N1 avian influenza in additional dairy herds, bringing the total to 504 infected herds and approaching half of the state's dairy herds. See PHC alerts from 11/22, 11/21, and 11/15 for information about earlier totals. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of an additional H5N1 case in a dairy worker is not unexpected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of an additional H5N1 case in a dairy worker is not unexpected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California reported another case of H5N1 avian influenza in a dairy worker, totaling 31 dairy industry-related cases and 32 H5N1 cases in the state this year. No human-to-human spread of H5N1 has been detected. [Confidence: Very High]
SHOW LESSPHC will monitor the event and provide updates as needed. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees....SEE MORE
PHC will monitor the event and provide updates as needed. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees.
H5N1 has been identified in a wastewater sample in Clark County, Nevada, the state's 1st H5N1 detection since a poultry outbreak in March 2023. An investigation is underway to determine the source. Nevada has not identified H5N1 in dairy cows or humans. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California reported 2 new cases of H5N1 avian influenza in dairy workers, totaling 30 dairy industry-related cases and 31 H5N1 cases in the state this year. No human-to-human spread of H5N1 has been detected. [Confidence: Very High]
SHOW LESSBusinesses and individuals should dispose of any affected products. H5N1 avian flu and other pathogens have been found in raw milk. Pasteurization inactivates H5N1, making pasteurized milk and milk products safe to consume. ...SEE MORE
Businesses and individuals should dispose of any affected products. H5N1 avian flu and other pathogens have been found in raw milk. Pasteurization inactivates H5N1, making pasteurized milk and milk products safe to consume.
California issued an alert regarding a second recalled batch of cream top, whole raw milk from Raw Farm of Fresno County found to be contaminated with H5N1 avian flu. The affected milk is lot code 20241119 with a "best by" date of Dec 7. No illnesses have been identified tied to the contaminated product. [Confidence: Very High]
SHOW LESSBusinesses and individuals should dispose of any affected products. H5N1 avian flu and other pathogens have been found in raw milk. Pasteurization inactivates H5N1, making pasteurized milk and milk products safe to consume. ...SEE MORE
Businesses and individuals should dispose of any affected products. H5N1 avian flu and other pathogens have been found in raw milk. Pasteurization inactivates H5N1, making pasteurized milk and milk products safe to consume.
California issued an alert regarding one recalled batch of cream top, whole raw milk from Raw Farm of Fresno County found to be contaminated with H5N1 avian flu. The affected milk is lot code 20241109 with a "best by" date of Nov 27. No illnesses have been identified tied to the contaminated product. [Confidence: Very High]
SHOW LESSFor information only. Pennsylvania's decision to test milk for H5N1 is a proactive step in a state with no known cases. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees....SEE MORE
For information only. Pennsylvania's decision to test milk for H5N1 is a proactive step in a state with no known cases. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees.
Pennsylvania now requires bulk testing of milk for H5N1 from its farms. The decision is prompted by the steady increase of infected farms nationally; Pennsylvania has not found H5N1 in dairy herds. Farmers will not be responsible for the cost of testing, reducing a potential barrier to compliance. [Confidence: Very High]
SHOW LESSCalifornia's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
California's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California has confirmed H5N1 avian influenza in 336 dairy herds in California since the start of the avian flu outbreak in cattle, up from 278 herds as of 11/15. The current count of known H5N1-infected herds represents ~30% of California's dairy herds. See PHC alerts from 11/15, 11/4, and 10/28 for information about earlier totals. [Confidence: Very High].
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
Fresno County reported a case of H5N1 avian influenza in a Fresno County resident who had contact with infected cattle at a dairy farm in the Central Valley. This case is the 1st in Fresno County, and 24th in California. No human-to-human spread of H5N1 has been detected. [Confidence: Very High]
SHOW LESSOngoing testing in California and Utah is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Ongoing testing in California and Utah is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California confirmed 45 new H5N1-infected dairy herds and Utah identified 4 new herds in the last week, totaling 278 in CA and 13 in UT. See PHC alerts from 10/28, 10/22, 10/10, 10/8, and 10/3 for information about earlier H5N1 detections in California herds. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
Madera County, CA reported 2 human cases (1 confirmed and 1 presumptive) of H5N1 in workers with exposure to infected dairy cows. These are Madera County's 1st H5N1 human cases and CA's 22nd and 23rd. [Confidence: Very High]
SHOW LESSCalifornia's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
California's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California has confirmed H5N1 avian influenza in 259 dairy herds in California since the start of the avian influenza outbreak in cattle, up from 233 herds as of 11/4. See PHC alerts from 11/4, 10/28, 10/22, 10/10, and 10/8 for information about earlier H5N1 detections in California herds. [Confidence: Very High]
SHOW LESSFor information only. The finding that 7% of tested dairy workers had evidence of past H5N1 infection is concerning and adds urgency to preventing coinfection of H5N1 and seasonal flu. Businesses should follow the recommendations provided in the PHC analysis from October 22. Businesses should lower barriers to seasonal flu vaccines for their employees....SEE MORE
For information only. The finding that 7% of tested dairy workers had evidence of past H5N1 infection is concerning and adds urgency to preventing coinfection of H5N1 and seasonal flu. Businesses should follow the recommendations provided in the PHC analysis from October 22. Businesses should lower barriers to seasonal flu vaccines for their employees.
In a study, CDC detected a 7% H5N1 infection rate in certain dairy workers. As seasonal flu season commences, this finding raises the probability of a farm worker being coinfected with H5N1 and seasonal flu, which increases the opportunities for H5N1 to gain the ability to transmit from person to person. Additionally, CDC recommended: (1) increased testing (2) wider Tamiflu use in those most likely to have simultaneous infection with H5N1 and seasonal flu (e.g., dairy and poultry workers), and (3) expanded PPE. [Confidence: Very High]
SHOW LESSCalifornia's proactive testing is expected to detect additional human H5N1 cases. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
California's proactive testing is expected to detect additional human H5N1 cases. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California reported its 21st human case of H5N1 avian influenza and another probable case in workers with exposure to cattle. The CDC confirmed 46 human H5N1 cases. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. [Confidence: Very High]
SHOW LESSCalifornia's proactive testing is expected to detect additional human H5N1 cases. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
California's proactive testing is expected to detect additional human H5N1 cases. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California reported the 17th, 18th, 19th human cases of H5N1 avian influenza on 11/1 and the 20th case on 11/4; all workers had exposure to cattle. There have been 44 total human cases of H5N1 avian influenza reported in the US. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. [Confidence: Very High]
SHOW LESSCalifornia's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
California's proactive testing is expected to detect additional H5N1 cases in dairy herds. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California has confirmed H5N1 avian influenza in 233 dairy herds in California since the start of the avian influenza outbreak in cattle. See PHC alerts from 10/28, 10/22, 10/10, 10/8, and 10/3 for information about earlier H5N1 detections in California herds. [Confidence: Very High]
SHOW LESSIt is unsurprising that mandatory surveillance detected H5N1 at multiple dairies in Cache County, Utah. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. ...SEE MORE
It is unsurprising that mandatory surveillance detected H5N1 at multiple dairies in Cache County, Utah. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees.
8 commercial dairies in Cache County, Utah have detected H5N1 avian influenza in cattle after the earlier detection of the dairy-related H5N1 strain in commercial poultry in the same county (PHC alert 10/15). Utah initiated mandatory surveillance for H5N1 in all Cache County dairies after the poultry outbreak (PHC alert 10/24). A quarantine has been instituted restricting movement of dairy cows at infected facilities with an exemption for slaughter. [Confidence: Very High]
SHOW LESSInformational update only. Increased testing is likely to detect avian influenza in more dairy herds but aids in targeted use of biosecurity measures to limit further spread. Businesses should continue to follow the recommendations provided in the PHC analysis on Oct 22....SEE MORE
Informational update only. Increased testing is likely to detect avian influenza in more dairy herds but aids in targeted use of biosecurity measures to limit further spread. Businesses should continue to follow the recommendations provided in the PHC analysis on Oct 22.
The USDA will begin a nationwide bulk milk testing program starting in early Nov. Bulk testing of milk for H5N1 has previously been conducted in CA and CO, and was used for brucellosis detection in the past. Bulk testing helps identify undetected virus circulation so that biosecurity measures can be implemented to limit spread. [Confidence: Very High]
SHOW LESSFor information only. Earlier PHC Alerts have covered the key points in the CDC's latest Bird Flu Response Update. Businesses should continue to follow the guidance in the 10/22 analysis. Businesses should lower barriers to seasonal flu vaccines for their employees. ...SEE MORE
For information only. Earlier PHC Alerts have covered the key points in the CDC's latest Bird Flu Response Update. Businesses should continue to follow the guidance in the 10/22 analysis. Businesses should lower barriers to seasonal flu vaccines for their employees.
The CDC has confirmed 36 total human H5 avian influenza cases: 20 related to dairy cattle, 15 related to poultry, and 1 without known animal exposure (CA: 16, WA: 6, CO: 10, MI: 2, MO: 1, TX: 1). 387 dairy herds have been found infected across 14 states, with most new infections being identified in California. All of CA’s 16 human cases were genotyped to the strain affecting cattle and had mild symptoms of eye redness/discharge and/or mild respiratory symptoms. [Confidence: Very High]
SHOW LESSH5N1 infection in poultry workers culling birds is rare but not unexpected; the threat to business is unchanged. Businesses should lower barriers to seasonal flu vaccines for their employees. Businesses should follow the recommendations provided in the PHC analysis from October 22. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
H5N1 infection in poultry workers culling birds is rare but not unexpected; the threat to business is unchanged. Businesses should lower barriers to seasonal flu vaccines for their employees. Businesses should follow the recommendations provided in the PHC analysis from October 22. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
Washington state confirmed a 6th human case of H5N1. Two additional suspected cases have confirmatory tests pending. See PHC alerts from 10/28, 10/25, and 10/21 for more information on these cases in poultry workers. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers and herds is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers and herds is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California has reported a new human H5N1 avian influenza case in an individual with animal exposure, the state's 16th reported case. Additionally, 178 dairies have been confirmed infected in Central California. [Confidence: Very High]
SHOW LESSInformational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Measures to reduce H5N1 in dairy herds (e.g., vaccines, biosecurity measures) can `protect against economic impacts and can reduce the risk of H5N1 gaining an ability to sustain transmission from person to person. ...SEE MORE
Informational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Measures to reduce H5N1 in dairy herds (e.g., vaccines, biosecurity measures) can `protect against economic impacts and can reduce the risk of H5N1 gaining an ability to sustain transmission from person to person.
Two companies have been approved to conduct bovine H5N1 vaccine safety trials. One of the companies, Medgene, has already begun a field trial and expects the vaccine safety trial to be completed within 5 weeks. [Confidence: Very High]
SHOW LESSH5N1 infection in poultry workers culling birds is rare but not unexpected; the threat to business is unchanged. Businesses should follow the recommendations provided in the PHC analysis on October 22. Businesses should lower barriers to seasonal flu vaccines for their employees. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
H5N1 infection in poultry workers culling birds is rare but not unexpected; the threat to business is unchanged. Businesses should follow the recommendations provided in the PHC analysis on October 22. Businesses should lower barriers to seasonal flu vaccines for their employees. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
Update on H5N1 avian influenza cases in Washington poultry workers (see PHC Alert 10/21): the CDC confirmed H5N1 in 2 of the 4 presumptively positive cases in Franklin County. Confirmatory testing of the other 2 cases is pending. The workers were likely exposed during culling of H5N1 infected poultry. There is no evidence of human-to-human transmission. [Confidence: Very High]
SHOW LESSThe detection of H5N1 in two humans without known animal exposure is concerning, but lack of evidence for human-to-human transmission is good news. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
The detection of H5N1 in two humans without known animal exposure is concerning, but lack of evidence for human-to-human transmission is good news. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
Update to the Missouri H5N1 avian flu (clade 2.3.4.4b) case (see PHC alert 9/6): a household contact's lab tests indicated previous infection, but all healthcare workers were negative. Because the case and the family member experienced flu-like symptoms at the same time, common exposure is more likely than person-to-person transmission. This H5N1 mostly impacts dairy cattle and poultry; all other human cases had known animal exposure. [Confidence: Very High]
SHOW LESSIdentification of the dairy-associated strain of H5N1 in poultry outbreaks can signal undetected H5N1-infected dairy herds in states that have not reported infected cattle. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees....SEE MORE
Identification of the dairy-associated strain of H5N1 in poultry outbreaks can signal undetected H5N1-infected dairy herds in states that have not reported infected cattle. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees.
On 10/15 USDA reported an avian influenza outbreak at a large commercial egg operation in Cache County. PHC warned that if genetic analysis identified the dairy-related version of H5N1, it could indicate Utah had undetected H5N1-infected dairy herds. The dairy strain was subsequently identified, and Utah initiated mandatory testing for avian influenza in all dairies in Cache County. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on Oct 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on Oct 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California reported 1 new human H5N1 avian influenza case in a dairy worker, totaling 15 this year. Only animal-to-human transmission has been recorded in California, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. See PHC alerts from 10/22, 10/18, 10/15, 10/11, and 10/9 for more details about earlier human H5N1 cases in dairy workers. [Confidence: Very High]
SHOW LESSBusinesses whose operations are sensitive to the price of milk should increase their uncertainty level around cost projections as the full impact of H5N1 infections on dairy herds develops....SEE MORE
Businesses whose operations are sensitive to the price of milk should increase their uncertainty level around cost projections as the full impact of H5N1 infections on dairy herds develops.
Multiple media reports have cited Keith Poulsen, avian influenza researcher and Director of the Wisconsin Veterinary Diagnostic Laboratory, as asserting the mortality rate of California herds may be 15% - 20%, compared to the previously reported 2% in other states. The severe summer heat may be a factor. The reported 60-70% drop in milk production is also higher than previous estimates. Too little time has passed to know if infected cows will return to normal production for their next cycle. One source notes that younger cows are more impacted, which translates to the greatest financial impact since young cows have only just begun to produce milk. In combination, these factors could lead to significant losses to dairy farmers and volatility in milk and dairy product prices. [Confidence: Moderate]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should follow the recommendations provided in the PHC analysis on October 22, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
Merced County Department of Public Health has reported the county's first human H5N1 case in a dairy worker at a farm with infected cattle. The worker's contacts have been notified and are being monitored for symptoms. This case is the 14th in California. See PHC alerts on 10/21 and 10/18 for information on other recent human H5N1 cases in the state. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 2, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 2, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California has reported 2 new human H5N1 avian influenza cases in Central Valley dairy workers, totaling 13 this year. Only animal-to-human transmission has been recorded in California, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. See PHC alerts from 10/18, 10/15, 10/11, and 10/9 for more details about earlier human H5N1 cases in dairy workers. [Confidence: Very High]
SHOW LESSDetection of highly pathogenic avian influenza in more dairy herds is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Detection of highly pathogenic avian influenza in more dairy herds is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California has confirmed H5N1 avian influenza in 120 dairy herds in California since the start of the avian influenza outbreak in cattle while the US has confirmed H5N1 avian influenza in 320 herds. See PHC alerts from 10/10, 10/8, 10/3, 10/1, and 9/26 for information about earlier H5N1 detections in California herds. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 2, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 2, including lowering barriers to seasonal flu vaccines for their employees. The CDC is offering free seasonal influenza vaccines to farmworkers in high-risk states.
California confirmed the 5 additional suspected human H5N1 avian influenza infections in dairy workers (PHC alert 10/15). The total case count is now 11. CA launched a new dashboard tracking confirmed and presumptive human H5N1 cases with information describing the symptoms in humans, poultry, and cattle. The new webpage also instructs individuals in high-risk jobs (farm workers, wildlife workers) on how to prevent H5N1 infections and spread. [Confidence: Very High]
SHOW LESSFor information only. Multiple states have reported highly pathogenic avian influenza (HPAI) outbreaks in dairy herds. Michigan's thorough surveillance for avian flu is likely to identify additional infected herds and farms....SEE MORE
For information only. Multiple states have reported highly pathogenic avian influenza (HPAI) outbreaks in dairy herds. Michigan's thorough surveillance for avian flu is likely to identify additional infected herds and farms.
Michigan has detected HPAI in a Clinton County dairy herd but no human cases have been detected associated with this infected herd. This is the 30th infected herd in Michigan. 305 HPAI-infected herds have been reported in the United States since the beginning of the outbreak. For more information on Michigan HPAI-infections see PHC alerts 9/23, 9/10, 8/27, 8/2, 7/11, 7/10, 5/30, 5/24, 5/22, 5/21, 5/17, 5/16, and 5/8. [Confidence: Very High]
SHOW LESSGiven California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 2, including lowering barriers to seasonal flu vaccines for their employees....SEE MORE
Given California's proactive testing, the detection of additional H5N1 cases in dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 2, including lowering barriers to seasonal flu vaccines for their employees.
California is proactively testing symptomatic individuals for bird flu, allowing for better surveillance and detection of human cases than in many other states. California has now identified 6 confirmed and 5 possible human cases. The cases had direct contact with infected dairy cattle at 9 different farms. [Confidence: Very High]
SHOW LESSBusinesses in Utah who purchase local eggs may see price fluctuations. The 1.8 million birds culled represent a significant portion of all the egg laying hens in the state (~6 million in 2022)....SEE MORE
Businesses in Utah who purchase local eggs may see price fluctuations. The 1.8 million birds culled represent a significant portion of all the egg laying hens in the state (~6 million in 2022).
USDA reported the culling of 1.8 million chickens after avian influenza was identified in a "large commercial poultry flock” in northern Cache County. Nearby flocks have been quarantined. Detailed information about the flu type has not yet been released. Utah has not reported any H5N1 infected dairy herds; if the flock tests positive for the dairy strain of H5N1, it could indicate undetected dairy herd infections in the state. [Confidence: Very High]
SHOW LESSGiven the numerous dairy herd outbreaks in California, the detection of positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Given the numerous dairy herd outbreaks in California, the detection of positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Update to California's H5N1 cases among Central Valley dairy workers: one of the suspected new cases (see PHC alert 10/9) was confirmed to be positive. One other suspected case's confirmatory test is still pending. None of the human cases from California have had contact with one another and all cases are believed to be caused by contact with H5N1-infected dairy cows. [Confidence: Very High]
SHOW LESSDetection of highly pathogenic avian influenza in more dairy herds is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Detection of highly pathogenic avian influenza in more dairy herds is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California reported 17 more H5N1-infected dairy herds, totaling 99 infected herds. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No sustained human-to-human spread of H5N1 has been detected. See PHC alerts from 10/8, 10/3, 10/1, and 9/24 for more information. [Confidence: Very High]
SHOW LESSGiven the numerous dairy herd outbreaks in California, the detection of positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Given the numerous dairy herd outbreaks in California, the detection of positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California has confirmed a 3rd human H5N1 avian influenza case in a Central Valley dairy worker (PHC alert 10/7). CA reported 2 more possible human cases located in the Central Valley. CDC is conducting confirmatory testing. None of the human cases from California have had contact with one another and all cases are believed to be derived from contact with H5N1-infected animals. [Confidence: Very High]
SHOW LESSDetection of highly pathogenic avian influenza in more dairy herds is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Detection of highly pathogenic avian influenza in more dairy herds is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
26 more H5N1-infected dairy herds were identified in California, bringing the total to 82 infected herds. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No sustained human-to-human spread of H5N1 has been detected. See PHC alerts from 10/3, 10/1, and 9/24 for more information. [Confidence: Very High]
SHOW LESSGiven the numerous dairy herd outbreaks in California, the detection of positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Given the numerous dairy herd outbreaks in California, the detection of positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide new opportunities for the virus to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California is investigating a 3rd possible case of H5N1 avian influenza case in a Central Valley dairy worker with no known connection to the prior 2 human cases in California (see PHC alert 10/3). Samples have been sent to CDC for confirmatory testing. [Confidence: Very High]
SHOW LESSGiven the numerous dairy herd outbreaks in California, the detection of two positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide the virus new opportunities to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Contacts of the cases are being monitored. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Given the numerous dairy herd outbreaks in California, the detection of two positive dairy workers is not unexpected. No human-to-human spread of H5N1 has been detected, but additional human cases provide the virus new opportunities to acquire genetic changes. As flu season begins, the potential for co-infection of H5N1 and a seasonal flu is concerning. Contacts of the cases are being monitored. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
CDC tests have confirmed H5 avian influenza in 2 California dairy workers: a suspected case that the California Department of Public Health (CDPH) had previously announced (see earlier PHC alert 10/3) and a previously unreported individual. Both cases had mild symptoms, did not report respiratory symptoms, and were not hospitalized. [Confidence: Very High]
SHOW LESSEvidence of previously undetected H5N1 infections among dairy workers means that other cases likely occurred/are occurring. No human-to-human spread of H5N1 has been detected. PHC will continue to monitor and will communicate updated risk assessments as appropriate. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Evidence of previously undetected H5N1 infections among dairy workers means that other cases likely occurred/are occurring. No human-to-human spread of H5N1 has been detected. PHC will continue to monitor and will communicate updated risk assessments as appropriate. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California is investigating a possible case of H5N1 avian influenza case in a Central Valley dairy worker who handled H5N1-infected cattle. The preliminary test was positive for H5N1, and samples have been sent to CDC for confirmatory testing. The person's only symptom was conjunctivitis. 4 other US cases have been linked to the dairy industry since April (PHC alerts from 8/2, 7/5, and 5/30). [Confidence: Very High]
SHOW LESSHong Kong's import ban is a reminder that avian flu outbreaks can lead to economic losses. See PHC analysis on 4/26 for more information and guidance on the H5N1 dairy outbreaks....SEE MORE
Hong Kong's import ban is a reminder that avian flu outbreaks can lead to economic losses. See PHC analysis on 4/26 for more information and guidance on the H5N1 dairy outbreaks.
Hong Kong's Centre for Food Safety implemented an import ban on all poultry and egg imports from Merced County, California, and Orange County, Florida due to H5N1 outbreaks in these areas. 40,950 tons of poultry meat and 13.86 million eggs were imported to Hong Kong from the US in the first six months of 2024. [Confidence: Very High]
SHOW LESSDetection of highly pathogenic avian influenza in more dairy herds in multiple states is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Detection of highly pathogenic avian influenza in more dairy herds in multiple states is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
3 more H5N1-infected dairy herds were identified in California and 1 H5N1-infected dairy herd in Idaho, totaling 44 infected herds (CA) and 33 infected herds (ID) since the outbreak began. No human cases have been identified in these cattle outbreaks. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No sustained human-to-human spread of H5N1 has been detected. [Confidence: Very High]
SHOW LESSPoultry exporters should be prepared for additional export bans if they operate in countries with ongoing avian influenza outbreaks. Cost of poultry products may increase in areas with bans on importation of poultry....SEE MORE
Poultry exporters should be prepared for additional export bans if they operate in countries with ongoing avian influenza outbreaks. Cost of poultry products may increase in areas with bans on importation of poultry.
The Philippines banned the importation of live poultry, poultry products, and by-products from France after avian influenza started to spread within France in August (See PHC alert from 8/14). The Philippines regularly bans the import of birds and poultry products from countries with avian influenza outbreaks. [Confidence: Very High]
SHOW LESSSymptomatic contacts of an H5N1 clade 2.3.4.4b avian flu case in an individual without known exposure to animals is a concerning new development. Follow up testing will help determine if human-to-human transmission may have occurred. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
Symptomatic contacts of an H5N1 clade 2.3.4.4b avian flu case in an individual without known exposure to animals is a concerning new development. Follow up testing will help determine if human-to-human transmission may have occurred. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
Update to the recent human H5N1 avian flu case in Missouri (see PHC alerts 9/23, 9/16, 9/13 and 9/6): respiratory symptoms have been reported in 4 additional health care workers who were exposed to the avian influenza H5N1 clade 2.3.4.4b case after respiratory droplet precautions were put into place. Of the 6 healthcare workers exposed, 1 tested negative for H5N1 through PCR while the others' antibody test results are pending. Missouri has reported no confirmed human-to-human transmission. See PHC Highly Pathogenic Avian Influenza (HPAI) H5N1 critical threat for more information. [Confidence: Very High]
SHOW LESSDetection of highly pathogenic avian influenza in more dairy herds is not unexpected, though this is the largest number of infected herds in a state at one time. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Detection of highly pathogenic avian influenza in more dairy herds is not unexpected, though this is the largest number of infected herds in a state at one time. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
6 more H5N1-infected dairy herds were identified in California, totaling 42 infected herds in Sept. No human cases have been identified in these cattle outbreaks. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No sustained human-to-human spread of H5N1 has been detected. [Confidence: Very High]
SHOW LESSColombia's import ban is a reminder that fear of avian flu outbreaks can lead to economic losses even when the disease is not identified in the affected product. See PHC analysis on 4/26 for more information and guidance on the H5N1 dairy outbreaks....SEE MORE
Colombia's import ban is a reminder that fear of avian flu outbreaks can lead to economic losses even when the disease is not identified in the affected product. See PHC analysis on 4/26 for more information and guidance on the H5N1 dairy outbreaks.
Colombia is once again allowing U.S. beef imports from all states, including those with H5N1 dairy herd outbreaks. In April, Colombia implemented import restrictions in response to H5N1 dairy herd outbreaks, the only country to do so. H5N1 has only been identified in dairy cows; some beef cows were tested, but found to be negative. [Confidence: Very High]
SHOW LESSDetection of highly pathogenic avian influenza in more dairy herds is not unexpected, though this is the largest number of infected herds in a state at one time. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Detection of highly pathogenic avian influenza in more dairy herds is not unexpected, though this is the largest number of infected herds in a state at one time. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
18 more H5N1-infected dairy herds were identified in California, totaling 31 infected herds in Sept. No human cases have been identified in these cattle outbreaks. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No sustained human-to-human spread of H5N1 has been detected. [Confidence: Very High]
SHOW LESSEvidence of longer term economic impacts on dairy farms from H5N1 outbreaks increases the potential for supply chain challenges and product cost fluctuations. No sustained human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26....SEE MORE
Evidence of longer term economic impacts on dairy farms from H5N1 outbreaks increases the potential for supply chain challenges and product cost fluctuations. No sustained human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Michigan dairy farms have reported aborted calves, milk production losses, and livestock death from the highly pathogenic avian influenza (HPAI) H5N1 outbreak among dairy cattle. 29 dairy herds have been infected in Michigan, totaling 232 livestock herds across the US. On one farm in Michigan, milk production decreased by 25%, and 5% of the herd had to be culled resulting in $100K losses. [Confidence: Very High]
SHOW LESSSymptomatic close contacts of an H5N1 clade 2.3.4.4b avian flu case in an individual without known exposure to animals is a concerning new development. Follow up testing could help determine if human-to-human transmission may have occurred. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
Symptomatic close contacts of an H5N1 clade 2.3.4.4b avian flu case in an individual without known exposure to animals is a concerning new development. Follow up testing could help determine if human-to-human transmission may have occurred. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
Update to the recent human H5N1 avian flu case in Missouri (see PHC alerts 9/16, 9/13 and 9/6): a second close contact was identified, consisting of a healthcare worker who developed symptoms, but was never tested. Health officials are considering conducting follow up testing to determine if the close contacts may have evidence of previous H5N1 infection. CDC can only assist with an invitation from the state. [Confidence: Very High]
SHOW LESSThe detection of highly pathogenic avian influenza in more dairy herds is not unexpected. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No sustained human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in more dairy herds is not unexpected. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No sustained human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Six dairy herds in California tested positive for highly pathogenic avian influenza (HPAI) H5N1, totaling 17 dairy herd outbreaks in the state. No human cases have been identified in this current outbreak. [Confidence: Very High]
SHOW LESSInformational update only. ...SEE MORE
Informational update only.
Massachusetts tested its 95 licensed dairy herds for H5N1 and tests confirmed all were negative. MA is the 1st state to proactively test all herds for H5N1. [Confidence: Very High]
SHOW LESSInformational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms....SEE MORE
Informational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
Two dairy herds in Texas tested positive for highly pathogenic avian influenza (HPAI) H5N1, totaling 26 dairy herd outbreaks in the state. TX's last infected dairy herd was in Aug. No human cases have been identified in this current outbreak. [Confidence: Very High]
SHOW LESSFor informational purposes only. Canada's recommendation that farmers not bring cattle to major livestock events illustrates the ripple effects of outbreaks to business. PHC will continue to monitor the avian influenza H5N1 outbreak in cattle....SEE MORE
For informational purposes only. Canada's recommendation that farmers not bring cattle to major livestock events illustrates the ripple effects of outbreaks to business. PHC will continue to monitor the avian influenza H5N1 outbreak in cattle.
Due to the highly pathogenic avian influenza (HPAI) H5N1 outbreak currently spreading across the USA, Canada has advised farmers to not move cattle across international boundaries for USA agricultural exhibitions. [Confidence: Very High]
SHOW LESSInformational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms....SEE MORE
Informational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
A dairy herd in Idaho tested positive for highly pathogenic avian influenza (HPAI) H5N1, the state's 34th dairy herd outbreak. ID's last infected dairy herd was in Aug. No human cases have been identified in this current outbreak. [Confidence: Very High]
SHOW LESSThe detection of an H5N1 clade 2.3.4.4b avian flu case in an individual without known exposure to animals is a concerning new development. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
The detection of an H5N1 clade 2.3.4.4b avian flu case in an individual without known exposure to animals is a concerning new development. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
CDC reported that the recent human avian flu case in Missouri (see PHC alerts 9/13 and 9/6) was confirmed to be H5N1 clade 2.3.4.4b, closely related to the strain that has been infecting dairy cows. The case had a household contact who became symptomatic on the same day as the case but was never tested. [Confidence: Very High]
SHOW LESSInformational update. The detection of high levels of H5N1 in wastewater is concerning but not surprising; it does not require an immediate business response. The wastewater samples indicate the strain is persisting and that interventions like limiting livestock movement will not eradicate the strain as USDA hoped. Ongoing H5N1 infections offer the virus more opportunities to adapt to humans. PHC will continue to monitor H5N1 and update businesses as necessary....SEE MORE
Informational update. The detection of high levels of H5N1 in wastewater is concerning but not surprising; it does not require an immediate business response. The wastewater samples indicate the strain is persisting and that interventions like limiting livestock movement will not eradicate the strain as USDA hoped. Ongoing H5N1 infections offer the virus more opportunities to adapt to humans. PHC will continue to monitor H5N1 and update businesses as necessary.
Researchers reported H5N1 avian influenza in wastewater samples in 10 Texan cities and at 22/23 wastewater sampling sites. Their analysis suggests multiple animal sources contributed to the detection. H5N1 had already been discovered in Texas wastewater in spring 2024. See PHC Highly Pathogenic Avian Influenza (HPAI) H5N1 critical threat for more information. [Confidence: Very High]
SHOW LESSInformational update only. Australia has reported periodic avian flu outbreaks at poultry farms. ...SEE MORE
Informational update only. Australia has reported periodic avian flu outbreaks at poultry farms.
Victoria, Australia loosened some poultry industry restrictions following 2 months with no new avian flu cases. The last avian flu outbreak in Victoria was June 24. Former restricted areas have been reduced to control areas, which allows for animal movement and poultry no longer confined inside. [Confidence: Very High]
SHOW LESSThe detection of an H5 avian influenza case in a patient without known exposure to animals is a concerning new development. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
The detection of an H5 avian influenza case in a patient without known exposure to animals is a concerning new development. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
CDC reported that the recent H5 human case in Missouri (see PHC alert 9/6) had no clear exposure source. The case was deemed a "one off" with no increased risk of other human cases tied to this situation. [Confidence: Very High]
SHOW LESSThe detection of highly pathogenic avian influenza in another dairy herd is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in another dairy herd is not unexpected. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California identified H5N1 avian flu in 2 more dairy herds, totaling 5 infected herds this week and 8 in CA this year. No human cases have been detected associated with the California outbreak and no human-to-human spread of H5N1 has been detected. California produces about 20% of the US milk supply. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. [Confidence: Very High]
SHOW LESSThe detection of highly pathogenic avian influenza in another dairy herd is not unexpected. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in another dairy herd is not unexpected. California produces about 20% of the US milk supply. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California identified H5N1 avian flu in 3 dairy herds in Central Valley, totaling 6 infected dairy herds in the state this year. No human cases have been detected associated with this outbreak. [Confidence: Very High]
SHOW LESSMultiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms....SEE MORE
Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
A dairy herd in Shiawassee County, Michigan has tested positive for highly pathogenic avian influenza (HPAI) H5N1. This is the 29th dairy herd to test positive for HPAI in the state. No human cases have been identified in this current outbreak. [Confidence: Very High]
SHOW LESSThe detection of an H5 avian influenza case in a patient without known exposure to animals is a concerning new development. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate....SEE MORE
The detection of an H5 avian influenza case in a patient without known exposure to animals is a concerning new development. Businesses do not currently need to change their posture regarding H5N1 influenza. PHC will continue to monitor and will communicate updated risk assessments as appropriate.
Missouri reported its 1st human case of avian influenza A (H5). This case was discovered through routine influenza surveillance system as opposed to surveillance triggered by recent cattle outbreaks. As flu surveillance activity accelerates with the start of flu season, PHC will monitor closely for evidence of H5 becoming more common in people. See PHC Highly Pathogenic Avian Influenza (HPAI) H5N1 critical threat for more information. [Confidence: Very High]
SHOW LESSThe detection of highly pathogenic avian influenza in another dairy herd is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in another dairy herd is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Curry County, New Mexico reported a dairy herd infected with H5N1 avian flu, the state's 9th dairy herd outbreak. This is NM's 1st dairy herd outbreak since April. No human cases have been detected associated with this outbreak. [Confidence: Very High]
SHOW LESSThe detection of highly pathogenic avian influenza in another dairy herd is not unexpected. California produces about 20% of the US milk supply and the affected herds are in counties that produce over half of CA's milk output. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in another dairy herd is not unexpected. California produces about 20% of the US milk supply and the affected herds are in counties that produce over half of CA's milk output. The continued spread of H5N1 throughout the US increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
California confirmed that 3 dairy herds tested for positive for H5N1 avian flu (see PHC alert 8/30), the state's 1st H5N1 detection in dairy cows. CA is the 13th state to identify H5N1 among dairy herds. The affected herds are in Tulare, Merced, and Stanislaus counties. No human cases have been detected associated with this outbreak. [Confidence: Very High]
SHOW LESSBusinesses with interests in dairy may want to discuss milk testing programs and biosecurity measures such as worker PPE. No federally mandated bulk milk testing program has been implemented. The USDA has created a voluntary pilot weekly bulk milk testing program, which will reimburse farmers for lost milk production. Currently, only 33 dairy herds are being monitored nationally (1 in California). ...SEE MORE
Businesses with interests in dairy may want to discuss milk testing programs and biosecurity measures such as worker PPE. No federally mandated bulk milk testing program has been implemented. The USDA has created a voluntary pilot weekly bulk milk testing program, which will reimburse farmers for lost milk production. Currently, only 33 dairy herds are being monitored nationally (1 in California).
California reported investigating 3 dairy herds for H5N1 avian influenza. So far, 13 states have had dairy cattle test positive for H5N1. H5N1 can spread between wild birds, cattle, poultry, and between farms by farmworkers. [Confidence: Very High]
SHOW LESSInformational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. An H5N1 vaccine, used in conjunction with current biosecurity measures, could help minimize or control dairy herd outbreaks....SEE MORE
Informational update only. Multiple states have reported H5N1 avian flu outbreaks in dairy herds. An H5N1 vaccine, used in conjunction with current biosecurity measures, could help minimize or control dairy herd outbreaks.
The USDA announced that field trials will be conducted with a new H5N1 vaccine for use in dairy cows. The trial will assess vaccine safety, the first step towards widespread use of a vaccine. If the vaccine is found to be safe, effectiveness would be assessed next. [Confidence: Very High]
SHOW LESSMultiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms. ...SEE MORE
Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
Van Buren County, Michigan reported an H5N1 outbreak in a dairy herd, the state's 28th avian flu outbreak in a dairy herd this year. Michigan last reported a dairy herd H5N1 outbreak in late July. No human cases have been identified with this current outbreak. [Confidence: Very High]
SHOW LESSInformational update only. See PHC analysis on 4/26 for more information and guidance on the H5N1 avian flu outbreak....SEE MORE
Informational update only. See PHC analysis on 4/26 for more information and guidance on the H5N1 avian flu outbreak.
The second round of testing for live H5N1 virus in commercial dairy products were all found to be negative for live virus. 167 samples were tested from retail products, including aged raw milk cheese, pasteurized milk, and products made from pasteurized milk, such as pasteurized cheeses, cream cheese, butter, and ice cream. See PHC alerts 7/5 and 7/1 about earlier testing studies with commercial dairy products for H5N1. [Confidence: Very High]
SHOW LESSMultiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms. ...SEE MORE
Multiple states have reported H5N1 avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
USDA announced that they will add H5N1 avian flu to routine testing of culled dairy cows as part of their surveillance program, the National Residue Program (NRP). H5N1 testing will begin Sept 16. [Confidence: Very High]
SHOW LESSInformational update only. Increased surveillance for avian flu is likely to identify additional infected herds and farms. ...SEE MORE
Informational update only. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
Colorado reported another H5N1 outbreak in a dairy herd. This outbreak is occurring in a herd that had previously been infected in the spring. This is Colorado's 63rd dairy herd outbreak since April. [Confidence: Very High]
SHOW LESSInformational purposes only. Testing lactating cows participating in the State Fair reflects the ongoing concern about avian flu transmission between cows and humans. ...SEE MORE
Informational purposes only. Testing lactating cows participating in the State Fair reflects the ongoing concern about avian flu transmission between cows and humans.
The Nebraska State Fair is requiring H5N1 testing of all participating lactating dairy cows amid avian flu concerns. Nebraska has not identified any H5N1-infected dairy herds, but bordering states Colorado, Kansas and Iowa have all had dairy outbreaks. [Confidence: Very High]
SHOW LESSInformational update only. Increased surveillance for avian flu is likely to identify additional infected herds and farms. ...SEE MORE
Informational update only. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
Colorado reported 9 more H5N1 outbreaks among dairy herds, all detected via their required bulk-tank milk testing. Colorado has identified 63 H5N1-infected dairy herds since April. [Confidence: Very High]
SHOW LESSColorado, South Dakota, and Texas have reported new avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms. ...SEE MORE
Colorado, South Dakota, and Texas have reported new avian flu outbreaks in dairy herds. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
H5N1 avian flu was detected in 3 more dairy herds in the last week, totaling 181 dairy herd outbreaks from 13 states during 2024. The newest dairy herd outbreaks were identified in Colorado, South Dakota, and Texas. [Confidence: Very High]
SHOW LESSInformational update only. Enterprise businesses are not directly affected, but detection of H5N1 in new mammal species illustrates that the disease continues to spread to new animal groups. See PHC analysis on 4/26 for more information and guidance on this outbreak....SEE MORE
Informational update only. Enterprise businesses are not directly affected, but detection of H5N1 in new mammal species illustrates that the disease continues to spread to new animal groups. See PHC analysis on 4/26 for more information and guidance on this outbreak.
Weld County, Colorado reported detection of highly pathogenic avian influenza H5N1 in 3 new mammal species: deer mouse, prairie vole, and desert cottontail rabbit. [Confidence: Very High]
SHOW LESSEvidence of previously undetected H5N1 infections among dairy workers means that other cases likely occurred/are occurring. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Evidence of previously undetected H5N1 infections among dairy workers means that other cases likely occurred/are occurring. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Researchers reported that 2 Texas farmworkers had H5N1 antibodies, indicating that they had previously been infected with H5N1. Testing was done as part of a surveillance project on 2 Texas farms that had previously responded to an H5N1 outbreak among their cattle herds. [Confidence: Very High]
SHOW LESSMichigan has reported avian flu outbreaks among dairy herds and poultry farms. Increased surveillance for avian flu is likely to identify additional infected herds and farms. ...SEE MORE
Michigan has reported avian flu outbreaks among dairy herds and poultry farms. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
Michigan reported that H5N1 has been detected in another of their dairy herds, this one in a farm in Van Buren County. This is the 27th H5N1-infected herd in Michigan. [Confidence: Very High]
SHOW LESSInformational update only....SEE MORE
Informational update only.
CDC announced it will offer free seasonal flu vaccine to farm workers this fall. Dairy and poultry workers are at increased risk for H5N1 avian flu infection. Seasonal flu vaccine helps prevent seasonal flu infection but does not protect against H5N1 infection. Co-infection increases the risk of H5N1 mutating and becoming more transmissible to humans. [Confidence: Very High]
SHOW LESSInformational update only. ...SEE MORE
Informational update only.
WHO announced initiation of a program for pre-clinical H5N1 mRNA vaccine development. WHO will partner with Argentinian vaccine manufacturer Sinergium Biotech through the Technology Transfer Programme which aims to strengthen mRNA vaccine manufacturing capability in low- and middle-income countries. Findings will be shared with other manufacturing partners after pre-clinical development is complete. [Confidence: Very High]
SHOW LESSInformational purposes only. Banning lactating cows from the State Fair reflects the ongoing concern about avian flu transmission between cows and humans. ...SEE MORE
Informational purposes only. Banning lactating cows from the State Fair reflects the ongoing concern about avian flu transmission between cows and humans.
Minnesota reported banning birthing cows and newborn calves from the 2024 Minnesota State Fair due to concerns about avian flu spreading. Dairy cow-calf pairs can participate as long as the mother is not lactating. [Confidence: Very High]
SHOW LESSHuman cases of highly pathogenic avian influenza in poultry farm workers exposed to infected birds are not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Human cases of highly pathogenic avian influenza in poultry farm workers exposed to infected birds are not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Colorado reported 3 new human cases of H5N1 in poultry farm workers, totaling 10 human cases of H5N1 in Colorado this year. All 3 new cases had mild disease and worked at the same poultry farm in Weld County. This is the 2nd poultry farm in Weld County that has identified human cases of H5N1 (see PHC alerts 7/15 and 7/22 for info on previous cases). [Confidence: Very High]
SHOW LESSColorado has reported avian flu outbreaks among dairy herds, poultry farms, and human cases who work with infected animals. Increased surveillance for avian flu is likely to identify additional infected herds and farms. ...SEE MORE
Colorado has reported avian flu outbreaks among dairy herds, poultry farms, and human cases who work with infected animals. Increased surveillance for avian flu is likely to identify additional infected herds and farms.
The Colorado Department of Agriculture is mandating highly pathogenic avian flu (HPAI) testing of all commercial dairy cow bulk-tanks. Colorado has reported 2 spillover events in July involving an HPAI strain in dairy cows being detected in commercial poultry farms. [Confidence: Very High]
SHOW LESSHuman cases of highly pathogenic avian influenza in poultry farm workers exposed to infected birds is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Human cases of highly pathogenic avian influenza in poultry farm workers exposed to infected birds is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Colorado reported a new human case of H5N1 in a poultry farm worker and confirmed a previously suspected case (see PHC alert 7/15 for info). So far, 10 human cases of H5 avian flu have been identified in the US, 4 exposed to sick cows and 6 to sick poultry. [Confidence: Very High]
SHOW LESSColorado has had H5N1 outbreaks in both dairy herds and poultry farms. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Colorado has had H5N1 outbreaks in both dairy herds and poultry farms. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Colorado officials reported 5 more dairy herds infected with H5N1, totaling 116 infected herds across 13 states so far. No new human cases have been identified. [Confidence: Very High]
SHOW LESSApril milk samples from a farm in Oklahoma were recently submitted for testing when the business sought reimbursement for lost milk production. These cows are the first known H5N1 cases in Oklahoma. Businesses should continue to follow the recommendations provided in the PHC analysis on 4/26. ...SEE MORE
April milk samples from a farm in Oklahoma were recently submitted for testing when the business sought reimbursement for lost milk production. These cows are the first known H5N1 cases in Oklahoma. Businesses should continue to follow the recommendations provided in the PHC analysis on 4/26.
Oklahoma reported detection of H5N1 in a dairy herd, making it the 13th state to have H5N1-infected dairy cows. The samples were collected in April 2024, but not sent for testing until July. The delay underscores the significant gaps in H5N1 surveillance. Oklahoma has not reported any H5N1-infected birds in the state in 2024. No human cases have been identified with this new outbreak. [Confidence: Very High]
SHOW LESSMichigan and Minnesota have had H5N1 outbreaks in dairy herds and birds, so infected domestic cats in the affected areas are not unexpected. Businesses should continue to follow the recommendations provided in the PHC analysis from April 26. ...SEE MORE
Michigan and Minnesota have had H5N1 outbreaks in dairy herds and birds, so infected domestic cats in the affected areas are not unexpected. Businesses should continue to follow the recommendations provided in the PHC analysis from April 26.
3 cats tested positive for H5N1 avian influenza, 2 from Minnesota and 1 from Michigan. The 2 infected cats from Minnesota live on a dairy farm that has reported H5N1 in their herd. The cat from Michigan lives in the same county that has reported H5N1 in dairy herds. [Confidence: Very High]
SHOW LESSBenton County, Minnesota has had H5N1 outbreaks in dairy herds and birds, so this newest dairy herd outbreak is not unexpected. Businesses should continue to follow the recommendations provided in the PHC analysis from April 26. ...SEE MORE
Benton County, Minnesota has had H5N1 outbreaks in dairy herds and birds, so this newest dairy herd outbreak is not unexpected. Businesses should continue to follow the recommendations provided in the PHC analysis from April 26.
Benton County, Minnesota reported a dairy herd infected with H5N1 avian flu, totaling 9 infected herds in the state this year. This is the 4th infected herd in Benton County. [Confidence: Very High]
SHOW LESSGratiot County has had H5N1 outbreaks in both dairy herds and poultry farms, so this newest dairy herd outbreak is not unexpected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Gratiot County has had H5N1 outbreaks in both dairy herds and poultry farms, so this newest dairy herd outbreak is not unexpected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Gratiot County, Michigan reported a new H5N1 avian influenza outbreak in a dairy herd, the first dairy herd outbreak in the state since June 7 and the 26th Michigan herd affected. No human cases have been identified with this new outbreak. [Confidence: Very High]
SHOW LESSBusinesses with eggs sourced from Colorado should assess their supply chains. H5N1 in poultry presents low risk to humans....SEE MORE
Businesses with eggs sourced from Colorado should assess their supply chains. H5N1 in poultry presents low risk to humans.
Colorado declared a state emergency after identifying an H5N1 avian influenza outbreak in a large commercial poultry farm in Weld County. About 1.8 million chickens will be culled, the 2nd largest in the state's history. Poultry quarantine and movement ban have been implemented. [Confidence: Very High]
SHOW LESSThis newest study provides further evidence that drinking raw milk may pose an infection risk. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. ...SEE MORE
This newest study provides further evidence that drinking raw milk may pose an infection risk. Pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume.
The FDA reported results from a study indicating that 14% of raw milk samples tested were found to contain infectious H5N1 avian flu. The study involved testing raw milk from 4 states with dairy herds infected with H5N1 avian flu. This is the same study described in PHC alert on 7/1. [Confidence: Very High]
SHOW LESSAnother human case of highly pathogenic avian influenza in a dairy worker exposed to infected cows is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Another human case of highly pathogenic avian influenza in a dairy worker exposed to infected cows is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
A 4th human case of avian flu tied to the US dairy industry has been identified, the first case in Colorado. The case works at a dairy farm with cows who have tested positive for H5N1. Preliminary testing indicates the case's strain is H5 and is likely to be H5N1 given exposure to infected cows, but full genetic testing is pending. The case only has eye symptoms. [Confidence: Very High]
SHOW LESSThis newest study provides further evidence that pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume. ...SEE MORE
This newest study provides further evidence that pasteurization inactivates the H5N1 virus, making pasteurized milk and milk products safe to consume.
The FDA reported results from a study confirming that pasteurization kills H5N1 avian flu in milk and milk products. The study involved inoculating homogenized raw milk with higher levels of H5N1 virus than those found in samples of contaminated raw milk, pasteurizing it using typical pasteurization time and temperature requirements, and then checking for live virus. Results indicate that pasteurization inactivated the virus. [Confidence: Very High]
SHOW LESSBusinesses should expect the detection of avian influenza to continue. At this point, widespread disruption to the milk supply is not anticipated....SEE MORE
Businesses should expect the detection of avian influenza to continue. At this point, widespread disruption to the milk supply is not anticipated.
An eleventh dairy herd in Iowa has reported positive HPAI detection. Iowa is considering adopting testing requirements similar to those implemented in Wisconsin for animals brought to agricultural fairs to reduce the risk of cow-to-human transmission. See PHC Alert from 6/17 for related information. [Confidence: Very High]
SHOW LESSBusinesses should expect the detection of avian influenza to continue. At this point, widespread disruption to the milk supply is not anticipated....SEE MORE
Businesses should expect the detection of avian influenza to continue. At this point, widespread disruption to the milk supply is not anticipated.
A fourth dairy herd in Sioux County, Iowa tested positive for avian influenza, bringing the total number of herds in Iowa impacted to six. Iowa is considering adopting testing requirements similar to those implemented in Wisconsin for animals brought to agricultural fairs to reduce the risk of cow-to-human transmission. [Confidence: Very High]
SHOW LESSInformational update only....SEE MORE
Informational update only.
USDA APHIS reported that 36 more house mice in Roosevelt County, New Mexico have tested positive for H5N1 avian influenza, totaling 47 so far. The mice were found at a poultry farm in New Mexico that also had a red fox that tested positive for H5N1. See PHC alert 6/5 for more info. [Confidence: Very High]
SHOW LESSInformational update. Dairy cattle in the state have tested positive for the disease, and infected cattle or birds are the most likely source of the wastewater detection. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to humans. ...SEE MORE
Informational update. Dairy cattle in the state have tested positive for the disease, and infected cattle or birds are the most likely source of the wastewater detection. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to humans.
Harris County, Texas reported detection of H5N1 avian influenza in wastewater samples. H5N1 was detected in 3 Texas dairy herds earlier this month. No human cases have been reported in the greater Houston area. [Confidence: Very High]
SHOW LESSInformational update only. This story highlights the flexibility of avian influenza in expanding its host range among mammals, and the ongoing risk this disease poses to human populations. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Informational update only. This story highlights the flexibility of avian influenza in expanding its host range among mammals, and the ongoing risk this disease poses to human populations. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
The H5N1 avian influenza strain involved in the human case in Texas was found to cause severe disease in ferrets. Ferrets are often used as a surrogate for human disease. Unlike seasonal flu, H5N1 was transmitted between ferrets via direct contact but not through respiratory droplets. [Confidence: Very High]
SHOW LESSThe detection of highly pathogenic avian influenza in another dairy herd is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in another dairy herd is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Highly pathogenic avian influenza has been confirmed in a Wyoming dairy herd, Wyoming's first detection. It is the 12th state to detect H5N1 in dairy cattle. The exact location of the affected herd has not been released. [Confidence: Very High]
SHOW LESSInformational update. Dairy cattle in the state have tested positive for the disease, and infected cattle or birds are the most likely source of the wastewater detection. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to humans. ...SEE MORE
Informational update. Dairy cattle in the state have tested positive for the disease, and infected cattle or birds are the most likely source of the wastewater detection. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to humans.
Austin-Travis County, Texas reported detection of traces of H5N1 in wastewater samples. H5N1 was detected in 3 Texas dairy herds earlier this month. No human cases have been reported in Austin. [Confidence: Very High]
SHOW LESSThe detection of highly pathogenic avian influenza in another dairy herd is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in another dairy herd is not unexpected. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
H5N1 has been confirmed in a Benton County dairy herd, Minnesota's first detection. It is the 11th state to detect H5N1 in dairy cattle. Stearns County reported H5N1 outbreaks in turkeys earlier this week.
SHOW LESSThe detection of highly pathogenic avian influenza in another dairy herd is not unexpected, especially given the recent H5N1 outbreak in a poultry farm in a neighboring county. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of highly pathogenic avian influenza in another dairy herd is not unexpected, especially given the recent H5N1 outbreak in a poultry farm in a neighboring county. No human-to-human spread of H5N1 has been detected. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Highly pathogenic avian influenza was identified in a new dairy herd in O'Brien County, Iowa, making Iowa the 10th state to reported infected livestock. Iowa is the 10th-leading milk-producing state. Neighboring Sioux County, IA recently reported an H5N1 outbreak among poultry. No new US human H5N1 cases have been identified since the last case on May 30. See PHC alerts 4/1, 5/22, and 5/30 for more info. [Confidence: Very High]
SHOW LESSUSDA APHIS added house mice to the list of mammals infected with H5N1. Media reports indicate the mice were at a dairy farm that has had infected cattle. ...SEE MORE
USDA APHIS added house mice to the list of mammals infected with H5N1. Media reports indicate the mice were at a dairy farm that has had infected cattle.
USDA APHIS reported that 11 wild house mice in Roosevelt County, New Mexico have tested positive for H5N1 avian influenza. The mice may have become infected after drinking raw milk from infected dairy cattle. [Confidence: Very High]
SHOW LESSInformational update only....SEE MORE
Informational update only.
The USDA has begun enrolling farms in its Voluntary H5N1 Dairy Herd Status Pilot Program, which aims to increase testing options and improve H5N1 surveillance. Farms participating in the program can test milk pooled from multiple animals instead of testing animals individually. Further, farms can be declared disease-free and allowed to resume animal transport if they test negative for three consecutive weeks. This program aims to ease the testing burden placed on farms by the April 24, 2024 federal testing order while still maintaining a high level of surveillance. [Confidence: Very High]
SHOW LESSInformational update. Other dairy cattle in the state have tested positive for the disease and infected cattle remain the most likely source of these wastewater detections. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to human or cattle populations. ...SEE MORE
Informational update. Other dairy cattle in the state have tested positive for the disease and infected cattle remain the most likely source of these wastewater detections. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to human or cattle populations.
Wastewater surveillance has identified H5N1 in North Carolina area where no previous outbreak had been detected. [Confidence: Very High]
SHOW LESSInformational update. Articles in previous weeks had presented the question of whether spikes in influenza A activity in San Francisco wastewater may result from undetected avian influenza spread. This most recent announcement confirms that the disease is present in the state but further confirms that it constitutes a small portion of the influenza A genetic material in local wastewater samples and is absent in the most recent testing. ...SEE MORE
Informational update. Articles in previous weeks had presented the question of whether spikes in influenza A activity in San Francisco wastewater may result from undetected avian influenza spread. This most recent announcement confirms that the disease is present in the state but further confirms that it constitutes a small portion of the influenza A genetic material in local wastewater samples and is absent in the most recent testing.
The San Francisco Department of Health has announced that two chickens at a wild bird market sampled at least 10 days ago have tested positive for H5N1. Testing of San Francisco wastewater at around the same time showed traces of H5N1, though follow-up testing failed to confirm the presence of the virus. The infected birds were asymptomatic and no additional cases of H5N1 in birds or humans have been reported. [Confidence: Very High]
SHOW LESSInformational update. These data reinforce that avian influenza genetic material is detectable within wastewater systems, though most detections are in areas of known activity. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to human or cattle populations. ...SEE MORE
Informational update. These data reinforce that avian influenza genetic material is detectable within wastewater systems, though most detections are in areas of known activity. Despite the flurry of recent media reports, there is no evidence that these outbreaks pose a substantial threat to human or cattle populations.
WastewaterScan, a wastewater monitoring partnership between Stanford and Emory Universities, has launched its H5 avian influenza monitoring system. Over the month of May, several wastewater samples from Michigan, Texas, Minnesota, Iowa, and Idaho tested positive for H5 influenza. Since the peak of detections in mid-May, the level of activity has steadily declined. [Confidence: Very High]
SHOW LESSThe detection of a third positive farm worker is not unexpected, but the presence of respiratory symptoms in this person combined with the mutation noted in last week's case in Michigan changes the overall picture. No human-to-human spread of H5N1 has been detected with this outbreak, but these developments reflect some of the necessary changes for the virus to acquire this ability. Contacts of the cases are being monitored. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of a third positive farm worker is not unexpected, but the presence of respiratory symptoms in this person combined with the mutation noted in last week's case in Michigan changes the overall picture. No human-to-human spread of H5N1 has been detected with this outbreak, but these developments reflect some of the necessary changes for the virus to acquire this ability. Contacts of the cases are being monitored. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
A 3rd human case of avian influenza H5N1 tied to the US dairy industry has been identified, the first person in this outbreak to have respiratory symptoms. The new case is a dairy farm worker in Michigan with no ties to the previous 2 cases. See PHC alerts 4/1 and 5/22 for more info. [Confidence: Very High]
SHOW LESSBusinesses with eggs sourced from Iowa should assess their supply chains and expect price fluctuations in response to production shortfall....SEE MORE
Businesses with eggs sourced from Iowa should assess their supply chains and expect price fluctuations in response to production shortfall.
Highly pathogenic avian influenza (HPAI) was detected in a commercial poultry flock in Sioux County, Iowa, the first in Iowa in 2024. HPAI was last detected in Iowa in fall 2023. Over 4 million chickens in the affected flock will be culled. [Confidence: Very High]
SHOW LESSEnterprise businesses are not directly affected, but detection of H5N1 in alpacas illustrates that the disease is spreading to new animal groups and to more areas. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
Enterprise businesses are not directly affected, but detection of H5N1 in alpacas illustrates that the disease is spreading to new animal groups and to more areas. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Alpaca have not previously tested positive for H5N1, but given the many other mammals that have been infected, this finding is not completely unexpected. The strain in the alpaca was the same as in poultry that had been culled on the premises; it is also the same as the strain found in US dairy cattle. [Confidence: Very High]
SHOW LESSPrior studies have found H5N1 is inactivated when proper food safety cooking recommendations are followed. Businesses should continue to follow food safety protocols when handling and cooking beef. See PHC analysis on 4/26 for more information and guidance on this outbreak....SEE MORE
Prior studies have found H5N1 is inactivated when proper food safety cooking recommendations are followed. Businesses should continue to follow food safety protocols when handling and cooking beef. See PHC analysis on 4/26 for more information and guidance on this outbreak.
Diverted cows are not allowed to enter the food chain. To date, one cow of the 96 cows tested has been positive for H5N1. No meat from these dairy cattle entered the food supply. [Confidence: Very High]
SHOW LESSBusinesses should not stock raw milk to avoid liability due to numerous diseases that can be transmitted in unpasteurized milk....SEE MORE
Businesses should not stock raw milk to avoid liability due to numerous diseases that can be transmitted in unpasteurized milk.
A laboratory study found mice that consumed raw milk positive for H5N1 contained high virus titers, indicating infection. Prior studies have confirmed that pasteurization inactivates the H5N1 virus, making it safe to drink. [Confidence: Very High]
SHOW LESSThe detection of H5N1 in additional dairy herds is not unexpected and does not indicate an immediate change in overall risk. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of H5N1 in additional dairy herds is not unexpected and does not indicate an immediate change in overall risk. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
H5N1 was detected in 7 new US dairy herds this week in Michigan (4 herds), Idaho (1), and Texas (1). See PHC alerts 4/1, 4/29, and 5/21 for more info. [Confidence: Very High]
SHOW LESSThe detection of a second positive farm worker is not unexpected and does not indicate an immediate change in overall risk. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26. ...SEE MORE
The detection of a second positive farm worker is not unexpected and does not indicate an immediate change in overall risk. Businesses should continue to follow the recommendations provided in the PHC analysis on April 26.
Michigan reported its first human case of H5N1 avian influenza in a farmworker who worked with livestock infected with H5N1. This is the first human case of H5N1 since March 29. See PHC alerts 4/1 and 4/29 for more info. [Confidence: Very High]
SHOW LESSHuman cases of H5N1 are rare; the risk of an outbreak is extremely low. Employees in or traveling to countries where human H5N1 cases have been identified, such as Vietnam or India, should avoid live-animal markets and not have contact with or consume diseased poultry....SEE MORE
Human cases of H5N1 are rare; the risk of an outbreak is extremely low. Employees in or traveling to countries where human H5N1 cases have been identified, such as Vietnam or India, should avoid live-animal markets and not have contact with or consume diseased poultry.
Australia reported a human case of H5N1, the first time H5N1 has been identified in a person or animal in Australia. The case is a child with a history of travel to India. Close contacts were monitored, but have not tested positive. [Confidence: Very High]
SHOW LESSInformational update only....SEE MORE
Informational update only.
Michigan reported that 3 more dairy herds have tested positive for H5N1, affected counties include Clinton, Gratiot, and Ionia. 18 dairy herds in MI have now had positive tests among their cows. [Confidence: Very High]
SHOW LESSH5N1 in eggs and poultry is killed by cooking; a new study results find the same for cooked beef. USDA recommends cooking beef to 160 degrees (well done). See PHC analysis on 4/26 for more information and guidance on this outbreak....SEE MORE
H5N1 in eggs and poultry is killed by cooking; a new study results find the same for cooked beef. USDA recommends cooking beef to 160 degrees (well done). See PHC analysis on 4/26 for more information and guidance on this outbreak.
A USDA study found that fully cooking beef inactivates the H5N1 virus, making it safe to eat. The study involved inoculating beef patties with an H5N1 virus surrogate, cooking it to different temperatures, and then checking for live virus. Results indicate that cooking the beef to medium or well done fully inactivated the virus. The study was conducted after H5N1 was found to infect dairy cows; there were concerns about beef cows becoming infected or posing a risk to the commercial beef supply. [Confidence: Very High]
SHOW LESSBusinesses with eggs sourced from Michigan should assess their supply chains and expect price fluctuations in response to production shortfall....SEE MORE
Businesses with eggs sourced from Michigan should assess their supply chains and expect price fluctuations in response to production shortfall.
Herbruck’s Poultry Ranch, Michigan's largest commercial egg producer, reported laying off 400 workers across 5 facilities. Due to H5N1, many commercial bird flocks are being culled--reducing the need for labor--and facilities decontaminated to prevent the spreading of H5N1, the first time this has been done in MI. Avian flu has affected the poultry industry since 2022, but this is the first time the commercial egg industry has been affected. Herbruck’s reported that they intend for the layoffs to be temporary. [Confidence: Very High]
SHOW LESSInformational update only....SEE MORE
Informational update only.
The USDA reported that H5N1 has been detected in 3 new dairy herds, 2 in Michigan and 1 in Idaho. 9 states have detected H5N1 in dairy herds, with Michigan having the most outbreaks (14). [Confidence: Very High]
SHOW LESSDetecting H5N1 in urban wild birds in NYC is not surprising since migratory birds interact with urban bird populations, but this has not been well documented. The current risk of human disease is low, but individuals should not interact with wild birds. ...SEE MORE
Detecting H5N1 in urban wild birds in NYC is not surprising since migratory birds interact with urban bird populations, but this has not been well documented. The current risk of human disease is low, but individuals should not interact with wild birds.
Researchers reported that 6 of 1,792 samples collected from wild birds in New York City tested positive for H5N1. The positive samples were found in a red tail hawk, Canadian geese, a Peregrine falcon, and a chicken. The H5N1 strains were a mix of Eurasian and North American avian flu viruses. [Confidence: Very High]
SHOW LESSInformational update only....SEE MORE
Informational update only.
19 of 23 sewage samples collected in 9 Texas cities tested positive for highly pathogenic avian influenza (HPAI). Samples were collected from 10 cities over two months, with 9 cities having at least one positive sample. Tests cannot identify the virus source as coming from animals, humans, or milk. [Confidence: Very High]
SHOW LESSThese test results indicate that H5N1 has not entered the Canadian dairy cattle population....SEE MORE
These test results indicate that H5N1 has not entered the Canadian dairy cattle population.
The Canadian Food Inspection Agency reported that tests conducted on 142 samples of their commercial milk supply have all tested negative for H5N1. Tests conducted on Canadian dairy cows have also been negative. [Confidence: Very High]
SHOW LESSRaw milk sales are rising due to misinformation on H5N1. Businesses should not stock raw milk to avoid liability due to numerous diseases that can be transmitted in unpasteurized milk....SEE MORE
Raw milk sales are rising due to misinformation on H5N1. Businesses should not stock raw milk to avoid liability due to numerous diseases that can be transmitted in unpasteurized milk.
Market research reports weekly sales of raw cow’s milk have increased 21% to 65% compared with the same period a year ago. Some social media influencers are promoting raw milk and making false statements about its safety and health benefits. [Confidence: Very High]
SHOW LESSBusinesses operating in Michigan should be aware of the new biosecurity protocols and have a plan for implementing them when applicable....SEE MORE
Businesses operating in Michigan should be aware of the new biosecurity protocols and have a plan for implementing them when applicable.
Michigan's biosecurity mitigation strategies aimed at preventing spread of H5N1 among cattle and poultry go into effect today. These practices must be implemented at all dairy farms and commercial poultry operations in Michigan until further notice. [Confidence: Very High]
SHOW LESSThese test results confirm that the commercial beef supply does not contain H5N1 virus. Businesses should continue to follow food safety protocols when handling and cooking beef. See PHC analysis on 4/26 for more information and guidance on this outbreak....SEE MORE
These test results confirm that the commercial beef supply does not contain H5N1 virus. Businesses should continue to follow food safety protocols when handling and cooking beef. See PHC analysis on 4/26 for more information and guidance on this outbreak.
Tests conducted on beef products by the USDA found no H5N1 avian influenza. The tests were conducted on ground beef sold in grocery stores in areas where dairy cows have tested positive for H5N1. [Confidence: Very High]
SHOW LESSDespite widespread media coverage, no new information has emerged. See PHC analysis on 4/26 for earlier assessment. Increased surveillance is likely to identify more human H5N1 cases among dairy workers, but the risk of human-to-human spread still remains low. ...SEE MORE
Despite widespread media coverage, no new information has emerged. See PHC analysis on 4/26 for earlier assessment. Increased surveillance is likely to identify more human H5N1 cases among dairy workers, but the risk of human-to-human spread still remains low.
The first human case of H5N1 tied to cow-to-human interaction was identified on March 29, soon after H5N1 was found to have infected dairy cows in multiple states. Since then, surveillance of poultry, cows, dairy products, and humans has increased. Investigation has found that multiple dairy workers had illnesses that may have been H5N1 around the time that dairy cows were testing positive, but before human surveillance activities had begun. [Confidence: Very High]
SHOW LESSInformational update only. Businesses may want to remind their employees to avoid consuming raw milk or feeding it to their pets as it may contain harmful pathogens....SEE MORE
Informational update only. Businesses may want to remind their employees to avoid consuming raw milk or feeding it to their pets as it may contain harmful pathogens.
Over half of the domestic cats on a Texas dairy farm who drank raw milk from cows infected with H5N1 died. The cats became sick one day after symptoms were noted in the cows (March 16/17). Several cats died between March 19–20. Two cats who died were tested for H5N1; both were positive. Cats are known to be susceptible to severe illness from H5N1. [Confidence: Very High]
SHOW LESSThese test results confirm that the commercial milk supply is safe. ...SEE MORE
These test results confirm that the commercial milk supply is safe.
Today, the FDA released the anticipated results from the egg inoculation studies that confirmed pasteurization inactivates H5N1 in dairy products. [Confidence: Very High]
SHOW LESSTaiwan's elevation of the travel advisory around H5N1 in Cambodia does not require businesses operating in Taiwan to make any changes, but employees on work travel to Cambodia may have additional questions. As previously noted, employees should avoid live-animal markets and not have contact with or consume diseased poultry. ...SEE MORE
Taiwan's elevation of the travel advisory around H5N1 in Cambodia does not require businesses operating in Taiwan to make any changes, but employees on work travel to Cambodia may have additional questions. As previously noted, employees should avoid live-animal markets and not have contact with or consume diseased poultry.
Cambodia has reported 4 human cases and 1 death related to H5N1 avian influenza A since mid-Jan 2024. All cases had contact with infected poultry. The Ministry of Health & Welfare issued a travel advisory to Cambodia, cautioning against interacting with poultry when visiting the area. H5N1 influenza is typically spread between birds (both domestic and wild) and can occasionally spread from birds to humans, but human-to-human transmission is extremely rare. Viral mutations could increase the potential for human-to-human transmission. [Confidence: Very High]
SHOW LESSInformational update only. Businesses may want to remind their employees to avoid consuming raw milk as it may contain harmful pathogens....SEE MORE
Informational update only. Businesses may want to remind their employees to avoid consuming raw milk as it may contain harmful pathogens.
Ohio reported that highly pathogenic H5N1 avian influenza (HPAI) was detected in a herd of dairy cattle, the first in this state. The infected cows were from Texas, a state which recently reported HPAI in some livestock, raw milk, and one farmer. The type of H5N1 identified in the cattle is the same that has been causing mass die-offs of birds around the world; it is different from the H5N1 that has caused human fatalities in the past. [Confidence: Very High]
SHOW LESSInformation update only. Standard industry practice is to cull all birds when Highly Pathogenic Avian Influenza is identified in a commercial flock. The risk of human disease remains low, but avian flu outbreaks in poultry can have a financial impact on businesses in the food industry and can also increase the price of consumer eggs and chicken. ...SEE MORE
Information update only. Standard industry practice is to cull all birds when Highly Pathogenic Avian Influenza is identified in a commercial flock. The risk of human disease remains low, but avian flu outbreaks in poultry can have a financial impact on businesses in the food industry and can also increase the price of consumer eggs and chicken.
Cal-Maine Foods reported detection of H5N1 avian influenza in a Texas flock, necessitating a temporary halting of egg production. The culled birds represent 3.6% of the company's birds. Eggs that are handled and cooked appropriately are safe to eat. [Confidence: Very High]
SHOW LESSInformational update included due to recent H5N1 cases in cattle and a human in Texas. The risk of human disease remains low, but avian flu outbreaks in poultry can have a financial impact on businesses in the food industry and can also increase the price of consumer chicken. ...SEE MORE
Informational update included due to recent H5N1 cases in cattle and a human in Texas. The risk of human disease remains low, but avian flu outbreaks in poultry can have a financial impact on businesses in the food industry and can also increase the price of consumer chicken.
Texas reported avian influenza H5N1 in a commercial poultry flock in a facility owned by the largest US egg producer. This comes just one day after H5N1 was identified in a farmer with exposure to infected cows. H5N1 influenza is typically spread between birds (both domestic and wild) and can occasionally spread from birds to other animals and humans, but human-to-human transmission is extremely rare. The type of H5N1 identified in the Texas poultry is the same that has been causing mass die-offs of birds around the world; it is different from the H5N1 that has caused human fatalities in the past. [Confidence: Very High]
SHOW LESSInformational update only. H5N1 has only been identified in dairy cows; beef cows are now being tested. Additionally, H5N1 has been proven to be killed by the cooking process with eggs and poultry; cooking beef is expected to be the same. See PHC analysis on 4/26 for more information and guidance on this outbreak....SEE MORE
Informational update only. H5N1 has only been identified in dairy cows; beef cows are now being tested. Additionally, H5N1 has been proven to be killed by the cooking process with eggs and poultry; cooking beef is expected to be the same. See PHC analysis on 4/26 for more information and guidance on this outbreak.
The USDA reported that they will conduct tests on beef to identify H5N1 avian influenza. 3 types of tests will be conducted: 1) sampling ground beef in grocery stores, 2) testing muscle tissue from sick cows culled from affected herds, and 3) testing cooked beef inoculated with a virus surrogate to see if it survives. [Confidence: Very High]
SHOW LESSInformational update only. Enterprise businesses are not directly affected, but detection of H5N1 in dolphins in North America illustrates that the disease is spreading to new animal groups and to more areas. See PHC analysis on 4/26 for more information and guidance on this outbreak....SEE MORE
Informational update only. Enterprise businesses are not directly affected, but detection of H5N1 in dolphins in North America illustrates that the disease is spreading to new animal groups and to more areas. See PHC analysis on 4/26 for more information and guidance on this outbreak.
Dixie County, Florida reported identification of a dolphin infected with highly pathogenic avian influenza H5N1, the first cetacean with H5N1 in North America. It is not known how the dolphin became infected. Researchers are investigating. Many other species of marine mammals have experienced H5N1-related die-offs. [Confidence: Very High]
SHOW LESSBusinesses with employees in or traveling to Vietnam should advise them to avoid live-animal markets and not have contact with or consume diseased poultry....SEE MORE
Businesses with employees in or traveling to Vietnam should advise them to avoid live-animal markets and not have contact with or consume diseased poultry.
Vietnam has reported a human death from H5N1 avian influenza; this is only Vietnam's second case since 2014. The individual had a history of exposure to wild birds. H5N1 influenza is typically spread between birds (both domestic and wild) and can occasionally spread from birds to humans, but human-to-human transmission is extremely rare. Viral mutations could increase the potential for human-to-human transmission. [Confidence: Very High]
SHOW LESSFor awareness only. USDA's policy requiring a negative H5N1 test to transport lactating cows goes into effect today. This requirement may detect additional outbreaks outside those in the 9 known impacted states....SEE MORE
For awareness only. USDA's policy requiring a negative H5N1 test to transport lactating cows goes into effect today. This requirement may detect additional outbreaks outside those in the 9 known impacted states.
The USDA now requires H5N1 testing of all lactating cows being transported across states. All lactating cows must be tested prior to travel, up to 30 cows per herd being transported. [Confidence: Very High]
SHOW LESSInformational update only. Enterprise businesses outside the dairy supply chain are not directly affected, but detection in a 9th state demonstrates that the outbreak might be more widespread than is currently known. See PHC analysis on 4/26 for more information and guidance on this outbreak....SEE MORE
Informational update only. Enterprise businesses outside the dairy supply chain are not directly affected, but detection in a 9th state demonstrates that the outbreak might be more widespread than is currently known. See PHC analysis on 4/26 for more information and guidance on this outbreak.
The USDA announced that highly pathogenic avian influenza (HPAI) H5N1 has been detected in dairy cows in Colorado, making it the 9th state to identify H5N1 in cows. No additional human H5N1 cases have been identified since the dairy farmer earlier this year; however, H5N1 is not included on standard respiratory panels. [Confidence: Very High]
SHOW LESSBusinesses in Cambodia should inform their employees to avoid live-animal markets and not have contact with or consume diseased poultry. ...SEE MORE
Businesses in Cambodia should inform their employees to avoid live-animal markets and not have contact with or consume diseased poultry.
A 9 year boy died of H5N1 avian influenza in Kratie province, Cambodia, the first death from avian influenza in Cambodia in 2024. Days later, his brother tested positive, but has been asymptomatic. The boys were exposed by infected poultry at their house; 5 chickens and 3 ducks had died and were cooked for food. Cambodia has been experiencing a resurgence of H5N1 human cases after a decade-long absence of cases. These brothers bring the number of human H5N1 cases in Cambodia in 2024 to four. Risk to the general population from H5N1 remains low, but sporadic cases will likely continue. [Confidence: Very High]
SHOW LESSInformational update only. Businesses may want to remind their employees to avoid consuming raw milk as it may contain harmful pathogens....SEE MORE
Informational update only. Businesses may want to remind their employees to avoid consuming raw milk as it may contain harmful pathogens.
Texas reported a human case of avian influenza H5N1, the second case in the US since 2022. The case developed conjunctivitis after contact with dairy cows presumed to be infected with avian influenza. H5N1 influenza is typically spread between birds (both domestic and wild) and can occasionally spread from birds to other animals and humans, but human-to-human transmission is extremely rare. The type of H5N1 identified in the cattle is the same that has been causing mass die-offs of birds around the world; it is different from the H5N1 that has caused human fatalities in the past. [Confidence: Very High]
SHOW LESSThis newly reported case of avian influenza (H5N1) in Cambodia does not require increased respiratory precautions for the general public. Individuals in close contact with poultry should use personal protective equipment....SEE MORE
This newly reported case of avian influenza (H5N1) in Cambodia does not require increased respiratory precautions for the general public. Individuals in close contact with poultry should use personal protective equipment.
A Cambodian man who kept backyard chickens has contracted H5N1 influenza. H5N1 influenza is typically spread between birds (both domestic and wild) and can occasionally spread from birds to humans, but human-to-human transmission is extremely rare. Viral mutations could increase the potential for human-to-human transmission.
SHOW LESSThe detection of H5N1 in Washington agricultural workers with exposure to infected commercial egg-laying hens, continued expansion of H5N1 in the dairy industry, and identification of an H5N1 case with no known exposure to infected poultry or cattle incre...SEE MORE
The detection of H5N1 in Washington agricultural workers with exposure to infected commercial egg-laying hens, continued expansion of H5N1 in the dairy industry, and identification of an H5N1 case with no known exposure to infected poultry or cattle increase the threat level for a H5N1 pandemic. PHC breaks down what has changed since H5N1 was first reported in dairy cattle earlier this year.
H5N1 in the dairy industry
Since H5N1 clade 2.3.4.4b was first identified in a Texas dairy herd in March 2024, outbreaks have expanded into 330 herds across 14 states. Most recently, in August 2024, H5N1 was first detected in California dairy herds; the outbreaks quickly expanded into 131 herds. During September, H5N1 was detected in dairy herds in Idaho, Texas, and Michigan, indicating geographical expansion of the H5N1 is not limited to California.
The first human H5N1 case tied to the dairy industry was identified in Texas in April 2024. Since then, 16 additional human cases have been reported. Most recently, a cluster of 13 H5N1 cases among California dairy workers was confirmed. All of the cases have been mild, and there is no evidence of person-to-person transmission. Transmission appears to be tied to milking without personal protective equipment.
Given California's proactive testing, the detection of additional H5N1-infected herds and dairy worker cases is to be expected. The continued spread of H5N1 throughout the US dairy industry increases the risk of volatility in milk prices; businesses that purchase milk and dairy products should maintain low confidence in cost projections.
Washington state’s first-ever human H5 cases in agricultural workers exposed to infected commercial birds
On October 20, 2024, Washington state reported its first-ever human cases of H5 in four agricultural workers who had exposure to H5N1-infected egg-laying hens at a commercial farm. Tests are pending for additional farm workers. The clade has not yet been identified, but the cases are presumed to have the same strain of H5N1 infecting chickens at the same farm. Washington has not yet detected the H5N1 clade 2.3.4.4b affecting dairy farms in the US. All infected workers had mild illness, and there is no evidence of person-to-person transmission. Across the United States, 15 confirmed H5N1 human cases with exposure to infected poultry have been reported this year.
Missouri human H5 case with no known exposure history
On September 6, 2024, Missouri health officials reported a human case of H5 avian influenza in an individual who had no known exposure to birds or other infection source. The case was found to have H5N1 clade 2.3.4.4b, closely related to the strain infecting dairy cows. Further investigation identified 6 healthcare workers exposed to the case, 4 of whom were symptomatic; 1 tested negative for H5N1, while the others' test results are pending. Testing was incomplete and delayed because Missouri was slow to involve the CDC, similar to some states’ previous response during COVID-19 and other emerging infectious disease outbreaks. Although person-to-person transmission was not thought to be occurring among farm workers, the lack of testing precludes ruling out person-to-person transmission within the healthcare setting.
Risk tied to upcoming flu season
As the 2024-2025 flu season begins, the potential for co-infection of H5N1 and a seasonal flu strain is concerning. Co-infection increases the likelihood of virus mutation.
How do these recent changes affect pandemic risk?
For a novel influenza virus to cause a serious pandemic, the virus must be able to transmit between people and to cause severe disease. Though recent H5 influenza cases among poultry and dairy workers have had mild disease and most have had only conjunctivitis, some have reported respiratory symptoms. Seasonal flu viruses are transmitted between people by replicating in the respiratory system and then spreading when someone coughs or exhales virus particles that infect others. While no sustained person-to-person transmission has been identified, continuation of dairy and poultry outbreaks, human cases, and the upcoming flu season increases the likelihood of virus mutation that could lead to a pandemic.
Actions your business can take now:
- For non-dairy-related businesses, these developments add urgency to the actions PHC has previously recommended (see "H5N1 in Dairy Cattle: What You Need to Know" from 5/9).
- Maintain or establish a work culture that supports employees’ decisions to wear masks.
- Maintain or increase the budget for cleaning supplies and hand sanitizer to avoid unexpected costs.
- Businesses that provide food services should plan for the price of milk and eggs to fluctuate when developing budgets.
- Dairy- and poultry-related businesses should evaluate their personal protective equipment practices for workers exposed to raw milk or chickens. While PPE provides the greatest worker protection, PPE adoption poses challenges for some workers. If regular use is not achievable, businesses should minimally consider selective adoption of PPE when H5N1 is suspected due to symptoms in cattle, poultry, humans, cats, or other mammals.
- Review your pandemic plan NOW, before there is an emergency.
Recent outbreaks of H5N1 in dairy cattle, poultry, and workers in these industries serve as a reminder that infectious disease outbreaks are inevitable. Companies should plan to review their pandemic plans annually and when potential threats emerge. Ensure that personnel information reflects changes due to staff turnover or contact information changes. Be clear on how decisions will be made regarding office closures, changes to remote work policies, cleaning schedules, and provision of supplies like hand sanitizer and masks.
- Evaluate planning for on-site flu vaccine clinics and employee communications this fall
Flu vaccination is important every year, but is even more essential this year. The CDC is offering free seasonal flu vaccine to dairy workers this year.
Businesses should provide flexible work schedules for employees to make vaccine appointments for themselves or their family members. Information on the availability of flu vaccines can also be included in employee wellness communication.
On-site flu shot clinics reduce barriers to employees getting annual vaccinations for seasonal flu. Contracting with these clinics can help protect your employees against seasonal influenza. If H5N1 evolves to spread easily between humans, an additional flu vaccine may be developed (as happened in 2010 during the H1N1 pandemic). If warranted, on-site flu clinics could potentially administer seasonal and H5N1 vaccines.
References:
- https://www.cdc.gov/bird-flu/situation-summary/mammals.html
- https://jamanetwork.com/journals/jama/fullarticle/2824960
- https://doh.wa.gov/newsroom/first-presumed-human-infections-avian-influenza-under-investigation-washington-state
- https://www.cdc.gov/bird-flu/spotlights/h5n1-response-09272024.html
Confidential and Proprietary
PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSHighlights Several recent studies have provided additional evidence that standard food safety practices protect US consumers from H5N1 exposure. To reduce the risk of employees getting sick, PHC recommends businesses not offer raw milk in their food serv...SEE MORE
Highlights
Several recent studies have provided additional evidence that standard food safety practices protect US consumers from H5N1 exposure. To reduce the risk of employees getting sick, PHC recommends businesses not offer raw milk in their food services. Businesses may wish to communicate the protection that pasteurization provides, as a recent survey showed fewer than half of US adults know that raw milk is less safe than pasteurized milk.
Survey: Majority of Americans do not understand the risks of raw milk
According to the Annenberg Public Policy Center’s latest health survey, only 47% knew drinking raw milk is less safe than drinking pasteurized milk. Also, 24% of Americans did not know that pasteurization is effective at killing bacteria and viruses in milk products. The germs in raw milk can cause foodborne illness with symptoms like diarrhea, stomach cramping, and vomiting. These infections can cause severe disease, hospitalization, or death.
More evidence that food safety practices protect against H5N1
- FDA released a preprint of a study confirming that commonly used and FDA-approved continuous flow high temperature short time pasteurization process inactivates the H5N1 virus. Researchers collected bulk raw milk samples, tested these samples for H5N1, and then tested again after pasteurization. No infectious virus was present after pasteurization, providing evidence the milk supply is safe. Media reports have noted that 14% of the collected raw milk samples had infectious H5N1, but the study was not designed to assess prevalence of infectious H5N1 in raw milk.
- In a Journal of Virology research article, the authors collected 297 samples from 23 pasteurized dairy product types collected from 17 states. Of these samples, 20% had H5N1 viral segments detectable by quantitative real-time RT-PCR, but no infectious virus was detected in the samples. These results support earlier studies showing infectious virus is not present in pasteurized milk products.
- In a small study published in the Journal of Food Protection, the authors inoculated beef patties with a low pathogenic avian influenza as a proxy for the highly pathogenic H5N1 that has been circulating in US dairy cattle. Cooking the beef patties to the USDA FSIS recommended minimum internal temperature of 71.1°C reduced the presence of the virus to “below detection,” indicating recommended food safety practices significantly reduce risk of exposure to the virus.
References:
- https://www.annenbergpublicpolicycenter.org/public-fails-to-appreciate-risk-of-consuming-raw-milk-survey-finds/
- https://www.cdc.gov/food-safety/foods/raw-milk.html
- https://www.fda.gov/media/179708/download
- https://pubmed.ncbi.nlm.nih.gov/38958444/
- https://pubmed.ncbi.nlm.nih.gov/38964610/
Confidential and Proprietary
PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSOn May 30, PHC published an analysis following articles in the Los Angeles Times (May 13) and the San Francisco Chronicle (May 28) that asked if high levels of influenza A in local wastewater systems were a sign of otherwise undetected avian influen...SEE MORE
On May 30, PHC published an analysis following articles in the Los Angeles Times (May 13) and the San Francisco Chronicle (May 28) that asked if high levels of influenza A in local wastewater systems were a sign of otherwise undetected avian influenza in people, livestock, or birds in those cities. Importantly, influenza A includes both seasonal influenza and H5N1 avian influenza. PHC concluded that avian influenza in California was extremely likely given its ubiquity among wild birds, but these cities’ distance from cattle herds and relatively low levels of influenza in wastewater made it extremely unlikely that avian influenza was driving the observed data. Instead, we believed local, human, seasonal influenza A activity drove the wastewater signal. Later data shown in a June 3 San Francisco Chronicle article confirmed this: only trace levels of avian influenza were detected in San Francisco wastewater in mid-May and could not be confirmed when the water was retested several days later. This article also highlighted the first detection of avian influenza in California this year - two chickens at a California live market.
Also on June 3, WastewaterSCAN, a joint monitoring system maintained by Stanford and Emory Universities, uploaded its first data on avian influenza detections across the United States during May. The California data was unremarkable, but the national data revealed compelling stories from several other areas across the United States. At the height of media attention during April-May, avian influenza was present at high concentrations in Iowa, Idaho, Minnesota, Michigan, and Texas. The limited number of sites covers a large geographical range and largely reflects areas with high cattle populations. The data indicate the likely extent of cattle infection, starting in January with the initial exposure event and propagating over the following months as infected animals moved around the country and spread the virus. These data are also consistent with a preprint research article posted in early May highlighting such movement based on genomic data.
The data from Texas and Michigan are particularly compelling, while data collected in Idaho and Iowa was sparse and less conclusive. Collection site data is summarized below.
Texas Data:
- Sharp spikes were recorded at two wastewater testing sites in the Dallas metropolitan area.
- Peak levels were observed on May 20, when avian influenza accounted for nearly half of all influenza A detected.
- Throughout May, over 25% of influenza A at these sites was avian influenza, indicating early and ongoing virus shedding, likely from dairy cattle.
Michigan Data:
- Spikes were observed at three wastewater sites across the state: Jackson, Warren, and Traverse City.
- Peak levels were observed around May 23, when avian influenza accounted for 30-40% of all influenza A detected.
- Levels declined after the peak but remained over 30% for the rest of May.
Minnesota Data:
- Notable spikes were noted in St Cloud (20% of influenza A), Red Wing (40%), and Mankato (48%) between May 22 and 24.
- The levels sharply declined after the initial spike.
What can we learn from this new data? First, the initial spikes in avian influenza detection, particularly in Texas, occurred before the substantial detections in dairy cows and milk which gained extensive media coverage in April and May. This timing once again highlights the importance of wastewater surveillance for tracking and responding to emerging infections. Second, and more concerning, the rapidity and range of these detections suggest a much broader distribution of avian influenza infection among cows over this period. Infections likely occurred across much of the country over a relatively short, 2-4 week period. While this outbreak in cattle has not posed a substantial threat to the general public or livestock, the rapid spread demonstrates how quickly a future pandemic could develop, and how difficult it would be to control.
The growing threat of avian influenza is real, especially as the disease becomes more entrenched in wild bird populations. The extensive interaction of infected wild birds with domestic animals, especially during migration, poses a substantial long-term threat to humans and livestock markets. The transit of livestock across the United States as part of the normal breeding, processing, and distribution cycle creates an easy way for disease to spread widely and quickly. It is essential for the United States to maintain a defensive posture against this emerging threat through intensive surveillance and comprehensive response plans to minimize the potential impact of future outbreaks. Businesses must maintain and regulaly update their pandemic and disruptive outbreak plans. See PHC's other recommendations in our April 26 analysis.
References:
- https://www.sfchronicle.com/health/article/h5n1-avian-flu-san-francisco-19489217.php
- https://www.latimes.com/environment/story/2024-05-13/is-there-bird-flu-in-california-wastewater
- https://www.sfchronicle.com/health/article/california-wastewater-h5n1-bird-flu-risk-19482460.php
- https://www.biorxiv.org/content/10.1101/2024.05.01.591751v1.full.pdf
- https://data.wastewaterscan.org/
Confidential and Proprietary
PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSThe detection of highly pathogenic avian influenza H5N1 in dairy cattle is a rapidly evolving multi-state outbreak. In the past week, Michigan has detected two human cases of avian influenza. PHC breaks down the implications below. How do these two cases ...SEE MORE
The detection of highly pathogenic avian influenza H5N1 in dairy cattle is a rapidly evolving multi-state outbreak. In the past week, Michigan has detected two human cases of avian influenza. PHC breaks down the implications below.
How do these two cases change the bigger picture?
For a novel influenza virus to cause a serious pandemic, the virus must be able to transmit between people and to cause severe disease. Last week’s Michigan case had a genetic change associated with greater virus replication and disease severity in mice. This week's case had respiratory symptoms, meaning the virus was behaving more like a typical flu infection. Seasonal flu viruses are transmitted between people by replicating in the respiratory system and then spreading when someone coughs or exhales virus particles that infect others. While no person-to-person transmission is suspected in these cases, the changes in the virus are consistent with the kinds of changes required for spread between people.
How does this change the risk landscape for businesses?
For non-dairy-related businesses, these developments add urgency to the actions PHC has previously recommended (see "H5N1 in Dairy Cattle: What You Need to Know" from 5/9)
- Review your pandemic plan NOW, before there is an emergency.
- Evaluate planning for flu vaccine clinics on site in the fall. Note that if an H5N1 vaccine must be produced, it will be separate from the already formulated seasonal flu vaccine.
- Maintain or establish a work culture that supports employees’ decisions to wear masks.
- Maintain or increase the budget for cleaning supplies and hand sanitizer to avoid unexpected costs.
- Businesses that provide food services should plan for the price of milk and eggs to fluctuate when developing budgets.
Dairy-related businesses should evaluate their personal protective equipment practices for workers exposed to raw milk. While adoption of PPE provides the greatest worker protection, summer weather can make PPE challenging to utilize. If regular use is not achievable, businesses should minimally consider selective adoption of PPE when H5N1 is suspected due to symptoms in cattle, humans, cats, or other mammals.
Is Michigan a hot spot for H5N1?
Michigan’s strong active surveillance is likely producing better detection of H5N1 in both humans (2 cases) and dairy herds (22 of the 69 infected herds in the US) than in other US states.
Why is the latest case described as an H5 infection and not H5N1?
The tests for the neuraminidase (the N in the subtype) are pending genetic sequencing at CDC.
References:
- https://www.cdc.gov/flu/avianflu/spotlights/2023-2024/h5n1-technical-update-may-24-2024.html
- https://www.cdc.gov/media/releases/2024/p0530-h5-human-case-michigan.html
- https://www.michigan.gov/mdard/about/media/pressreleases/2024/05/01/mdard-director-signs-hpai-risk-reduction-response-order-for-hpai-outbreak-animal-health-emergency
- https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock
Confidential and Proprietary
PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSKey Points Based on PHC's internal analysis, the elevated influenza A concentrations in San Francisco Bay Area wastewater do not indicate any immediate threat of avian influenza infection in humans; the signal is likely driven by human seasonal influenza ...SEE MORE
Key Points
- Based on PHC's internal analysis, the elevated influenza A concentrations in San Francisco Bay Area wastewater do not indicate any immediate threat of avian influenza infection in humans; the signal is likely driven by human seasonal influenza infection.
- While we cannot rule out contamination from agricultural runoff or entirely exclude the contribution of avian influenza without sequencing data, influenza A levels in local wastewater are within reasonable margins given local seasonal flu activity.
- Current and future infection of California cattle herds with avian influenza remains highly probable.
Background
Earlier in May, an article in the Los Angeles Times considered whether elevated influenza A activity in local wastewater was potentially due to otherwise undetected avian flu transmission. On Tuesday evening, a similar article ran in the San Francisco Chronicle, citing ongoing elevated levels of influenza A in Bay Area wastewater, speculated if avian influenza activity—particularly in local dairy cows—may be behind the increase.
Analysis
Consideration #1: This year's flu season has been marked by lingering case activity throughout the United States, with California continuing to report some of the highest influenza infection rates. Compared to the height of flu season, California's infection rates are substantially lower, as is the influenza A wastewater signal, which traditionally lags behind case and hospitalization data. Lastly, wastewater data is highly variable, and increases may be an artifact of the data.
Consideration #2: California's Central Valley is home to some of the country's most dense dairy cattle populations. The runoff from the farms housing these cattle follows the Bay Delta watershed and ultimately empties into the San Francisco Bay, raising the possibility that some of the influenza A signal we are observing in the San Francisco area may be due to runoff from these farms or the dumping of milk from infected cows. However, given the journey and amount of dilution that would occur between those farms and the sampling sites, a sizable H5N1 outbreak would need to occur to drive the observed trends in wastewater data, which PHC believes is unlikely.
Conclusion
It is unlikely that the elevated influenza A activity in the Bay Area wastewater indicates substantial human exposure to avian influenza. However, avian influenza in mammalian populations, including humans, is a serious and growing public health concern. Diligent surveillance activities and ongoing wastewater testing are essential to address this growing threat. PHC continues to track data and will provide clarity on the H5N1 threat.
References:
- https://www.latimes.com/environment/story/2024-05-13/is-there-bird-flu-in-california-wastewater
- https://www.sfchronicle.com/health/article/california-wastewater-h5n1-bird-flu-risk-19482460.php
- https://www.cdc.gov/flu/weekly/usmap.htm
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PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSHong Kong’s ban on poultry imports from some countries does not reflect a change in the threat posed by food and is a reminder that these actions can be issued for both safety and political reasons. On Monday, the Centre for Food Safety in Hong Kong ann...SEE MORE
Hong Kong’s ban on poultry imports from some countries does not reflect a change in the threat posed by food and is a reminder that these actions can be issued for both safety and political reasons.
On Monday, the Centre for Food Safety in Hong Kong announced a ban on poultry meat and egg imports from several countries, including the US, citing the risk posed by H5N1 avian influenza. Within hours, Macau, another special administrative region of China, issued a similar announcement which, while not as direct as Hong Kong’s announcement, also implied an immediate ban on US poultry imports.
These bans follow the recent announcement of a human fatality from another strain of avian influenza in mainland China’s Fujian province, and occur during a period of heightened global attention to the ongoing threat of avian influenza in poultry, livestock, and humans, which has led to other import bans, including a US ban on poultry imports from areas of Australia announced last week.
There is historical precedent for these sorts of actions. In 2015, following a similar period of heightened global awareness of avian influenza, Hong Kong announced a comparable ban of US poultry products which was part of a broader Chinese ban of US poultry products. The restrictions lasted nearly 5 years, far exceeding the period of heightened bird flu activity used to justify the ban. Since then, China has issued numerous shorter bans on poultry imports during periods of US avian influenza outbreaks. While Chinese imports of US poultry products accounts for less than 1% of US to China export value, it does equate to over $1 billion annually for US farmers.
At present, this action is limited and may be temporary. However, based on the nature of US-China trade relations, the risk does still exist for these restrictions to escalate into a broader and more lasting ban. It is important to reiterate that, while long-term public health risk from avian influenza is real and growing, immediate risk from the food supply is small. When infected chickens are handled properly, the risk of avian influenza entering the food chain is negligible and there is no evidence to date that consumption of contaminated poultry products can lead to disease in humans.
Lastly, import bans are sometimes used for political reasons. In addition to protectionism, import bans can frame a disease as a foreign threat to the domestic audience. Given that Hong Kong’s 1997 H5N1 cases represent the first example of a purely avian virus causing respiratory disease and death in humans, the new ban is inconsistent with the known ecology of avian influenza viruses.
References:
- https://www.info.gov.hk/gia/general/202405/27/P2024052700473.htm?fontSize=1
- https://www.gov.mo/zh-hant/news/1066966/
- https://www.abc.net.au/news/rural/2024-05-25/united-states-of-america-bans-victorian-poultry-products/103893610
- https://www.cidrap.umn.edu/avian-influenza-bird-flu/china-reports-fatal-h5n6-avian-flu-case-0
- https://www.cfs.gov.hk/english/press/20150122_0152.html
- https://southernagtoday.org/2023/09/07/the-rise-and-fall-of-u-s-chicken-feet-in-china-a-story-of-bird-flu-and-trade-bans/
- https://oec.world/en/profile/bilateral-country/usa/partner/chn
- https://www.fda.gov/food/egg-guidance-regulation-and-other-information/questions-and-answers-regarding-safety-eggs-during-highly-pathogenic-avian-influenza-outbreaks
- https://www.annualreviews.org/deliver/fulltext/food/2/1/annurev-food-022510-133710.pdf?itemId=/content/journals/10.1146/annurev-food-022510-133710&mimeType=application/pdf
- https://www.pnas.org/doi/full/10.1073/pnas.132268999
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PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSAs grilling season heats up in the Northern Hemisphere, it is crucial to ensure meat is cooked to safe temperatures to prevent foodborne illness. While H5N1 has not been identified in retail beef, the current H5N1 outbreak among dairy cows warrants takin...SEE MORE
As grilling season heats up in the Northern Hemisphere, it is crucial to ensure meat is cooked to safe temperatures to prevent foodborne illness.
While H5N1 has not been identified in retail beef, the current H5N1 outbreak among dairy cows warrants taking additional precautions to ensure food safety. In a question-and-answer session with reporters, USDA scientists disclosed that existing safe cooking temperature recommendations for ground beef and steaks are adequate to prevent H5N1 exposure through food.
The USDA reported that hamburgers cooked to 120° Fahrenheit–the temperature of a rare steak–still contained traces of an H5N1 surrogate virus. The H5N1 surrogate virus was killed in hamburgers cooked to 145° F (medium) and 160° F (well done). While steaks are safe from other microbial contamination when cooked to 145° F, the USDA considers ground beef safe only when cooked to 160° F (well done). A complete list of safe minimum temperatures is available on the USDA website.
In addition to preventing possible H5N1 transmission, cooking meat to recommended temperatures helps prevent other foodborne illnesses caused by other viruses, bacteria, and parasites. An estimated 9.4 million cases of foodborne illness occur in the United States each year, and approximately 55,000 cases require hospitalization. Foodborne illnesses result in more than 1,300 deaths each year.
For your safety, PHC strongly recommends using a food thermometer to ensure meats reach safe internal temperatures. This inexpensive and easy-to-use tool can significantly reduce the incidence of foodborne illnesses.
References:
- https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock/h5n1-beef-safety-studies
- https://wwwnc.cdc.gov/eid/article/17/1/p1-1101_article
Confidential and Proprietary
PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSA recent preprint study of cow tissue may bode well for the beef industry and explain the unusual way that H5N1 appears to spread among dairy cows in the United States. Researchers studied various tissues present in dairy cows and identified that memory ...SEE MORE
A recent preprint study of cow tissue may bode well for the beef industry and explain the unusual way that H5N1 appears to spread among dairy cows in the United States.
Researchers studied various tissues present in dairy cows and identified that memory gland tissue–such as that found in a cow udder–contained a large number of the cell receptors that H5N1 binds to. Equally important, the study found low numbers of these H5N1 binding sites in respiratory and brain tissue.
These biological findings support the hypothesis that H5N1 is transmitted among cows by infected milk – likely small amounts of infected milk remaining on milking equipment. These findings also help explain why the most significant symptoms of H5N1 infection in dairy cows –mastitis and a drop in milk production–are unrelated to the respiratory and neurological systems, where H5N1 has previously been documented.
The beef industry should take notice of these findings. The 2.3.4.4b strain of the virus–in the absence of commercial milking equipment–may be hard to transmit between dairy cows and beef cattle or among beef cattle due to the low numbers of H5N1 receptor sites in the respiratory tract.
References:
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PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSAlthough the United States is the only country that has detected H5N1 in cows, the discovery can still have global impacts. Examination of genomic sequences points to a single viral introduction from birds to dairy cows. This specific H5N1 has mutation...SEE MORE
Although the United States is the only country that has detected H5N1 in cows, the discovery can still have global impacts.
Examination of genomic sequences points to a single viral introduction from birds to dairy cows. This specific H5N1 has mutations that allowed researchers to identify its reintroduction into wild migratory birds. Spillback into migratory birds–or wild mammals–introduces the possibility of the dairy cattle H5N1 strain spreading throughout the United States and to additional countries. Migratory birds have spread earlier versions of H5N1 along their flyways, allowing new viruses to travel the world within two years.
Contaminated milking equipment is suspected of transmitting H5N1 between dairy cows, and the movement of dairy cattle can introduce the virus to new farms. Because dairy and beef operations are separate, dairy cows are unlikely to spread H5N1 to beef cattle directly. However, the fact that H5N1 was introduced to dairy cows does not eliminate the possibility of a future introduction to beef cattle. Understanding more about the mechanism by which H5N1 spreads between dairy cows is critical to understanding the possible impacts of H5N1 to beef cattle. Dairy cattle appear to recover fully after infection, with limited lost milking days. For beef cattle, a similar impact could be less efficient weight gain.
Agricultural businesses and businesses sensitive to the cost of poultry and cattle products should prepare for the possibility of H5N1 spreading to cattle beyond the United States. While pasteurization of dairy products and proper cooking of meat can ensure food safety, testing or treatment could increase production costs that may be passed to consumers.
The overall risk from H5N1 to the public is currently low. Because this strain of H5N1 does not spread readily from person-to-person, individuals working closely with birds and cows remain at the highest risk of infection. However, more research is needed to determine how transmissible this strain is from cows to humans. Ongoing genomic surveillance of H5N1 in cattle will be necessary to detect changes with implications for human health.
PHC will update this assessment as conditions change.
References:
- https://media.un.org/unifeed/en/asset/d320/d3202385
- https://twitter.com/MichaelWorobey/status/1782756133402509587/photo/1
- https://www.sciencedirect.com/science/article/pii/S0006320723001428#f0005
- https://www.science.org/content/article/bird-flu-may-be-spreading-cows-milking-and-herd-transport
Confidential and Proprietary
PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSThe detection of highly pathogenic avian influenza H5N1 in dairy cattle is a rapidly evolving multi-state outbreak. In this analysis, PHC assesses the current situation and describes low-effort actions to take now. Details for each bullet are available a...SEE MORE
The detection of highly pathogenic avian influenza H5N1 in dairy cattle is a rapidly evolving multi-state outbreak. In this analysis, PHC assesses the current situation and describes low-effort actions to take now. Details for each bullet are available at the end of the analysis.
Brief Overview:
In March 2024, highly pathogenic avian influenza (HPAI) H5N1 was detected in a dairy herd in Texas. In the following weeks, 33 herds in 8 states tested positive for H5N1. This week, viral fragments were found in grocery store milk. HPAI H5N1 has been devastating to poultry operations for several years. Before the current strain emerged, H5N1 had a roughly 50% mortality rate in humans, but the current strain (H5N1 2.3.4.4b) typically causes mild disease in people. The current outbreaks in cattle do not pose an immediate threat to employee safety or work continuity for enterprise businesses, but the situation is rapidly evolving. PHC details low-effort actions businesses can take now to prepare for potential shifts in the virus behavior.
PHC's assessment:
- H5N1 has been circulating in cows for many months. [Strong evidence]
- H5N1 genetic material is present in grocery store milk. [Strong evidence]
- Infectious H5N1 is not present in grocery store milk. [More evidence needed]
- Human infection with this H5N1 is often but not always mild. [More evidence needed]
- Person-to-person transmission of H5N1 is currently rare. [Strong evidence]
- Human infection with this strain of H5N1 is rare. [Not well investigated]
- H5N1 is susceptible to commercially available antiviral medicines used to treat seasonal influenza. [Strong evidence]
- Existing processes and manufacturing platforms can be used to jumpstart the development of a human vaccine against H5N1 if needed. [Strong evidence]
- PHC predicts restrictions on and testing requirements for dairy cattle movement will continue to evolve. [High confidence]
Unanswered questions:
- How did the first infection in a cow occur?
- How is H5N1 transmitted between cows and from cows to humans?
- How widespread is the outbreak?
- How feasible is it to control H5N1 transmission within commercial farms?
Actions your business can take now:
- Review your pandemic plan NOW, before there is an emergency.
- Evaluate planning for flu vaccine clinics on site in the fall.
- Maintain or establish a work culture that supports employees’ decisions to wear masks.
- Maintain or increase the budget for cleaning supplies and hand sanitizer to avoid unexpected costs.
- Businesses that provide food services should plan for the price of milk and eggs to fluctuate when developing budgets.
Evidence evaluation:
- Strong evidence: The statement is well supported by publicly available data and established scientific knowledge.
- More evidence needed: The statement is supported by evidence, but additional data is still needed (e.g., more testing required).
- Not well investigated: The statement has some evidence to support it, but significant gaps exist.
- Conflicting evidence: The statement has conflicting evidence, so more evidence is needed before drawing conclusions.
Additional details for items above:
H5N1 has been circulating in cows for many months. [Strong evidence]
On April 21, USDA released 249 genomic sequences to GISAID (the Global Initiative on Sharing Avian Influenza Data). Michael Worobey is a world-renowned expert in viral genomics who uses molecular and computational biology to understand how pandemics emerge and spread. Worobey’s team immediately analyzed the published sequences. Their analysis indicates the time of the most recent common ancestor (TMRCA) of the US cattle flu clade was late December, meaning this version of H5N1 has been circulating for months. Louise Moncla's lab at the University of Pennsylvania found similar results.
H5N1 genetic material is present in grocery store milk. [Strong evidence]
On April 23, the FDA reported that tests on grocery store milk had found genetic material from the same H5N1 virus identified in the sick dairy cattle. Quantitative polymerase chain reaction (qPCR) is a molecular biology technique used to determine the presence or absence of an organism’s DNA in a sample. The tests can identify pieces of the virus, which can be present even if the virus has been inactivated.
Andrew Bowman, a veterinary epidemiologist at Ohio State University, collected 150 commercial milk from 10 states. Using PCR, his team found 58 tested positive samples.
The discovery of H5N1 genetic material raises two questions. First, how widespread is the outbreak? The presence of H5N1 genetic material in milk may indicate that many more herds are impacted than known herds suggest. Secondly, are some infected cows not developing symptoms? If the cow appears well, dairy farms may not suspect infection and continue to milk the cow as usual.
Infectious H5N1 is NOT present in grocery store milk. [More evidence needed]
Although tests have detected the presence of viral H5N1 fragments in milk, that is not necessarily a cause for alarm. Pasteurization is likely to inactivate (kill) the virus but is not expected to remove inactive viral fragments from the milk.
Studies of pasteurization and virus inactivation indicate pasteurization should inactivate H5N1. Pasteurization was developed primarily to address the threat of infectious bacteria. Bacteria are typically much hardier than viruses. Additionally, influenza viruses are enveloped viruses and are more susceptible to heat and changes in pH.
Additional tests are being performed to confirm that these viral fragments are not capable of causing infection. Laboratory tests in which viral fragments are transferred to eggs to see if they can infect the eggs are currently in progress; the results of these tests are expected over the next few days.
Human infection with this H5N1 is often but not always mild [More evidence needed]
The US has identified two human cases of H5N1 in the past two years. The most recent case is a worker on the Texas dairy farm where H5N1 was identified; their only symptom was conjunctivitis. The other US case occurred in April 2022 in a person culling infected commercial poultry; they reported fatigue. Both cases recovered.
Internationally, several people have been infected with this H5N1 strain, including 5 asymptomatic cases in the UK and 2 asymptomatic cases in Spain. Chile, China, and Ecuador have reported a total of 4 severely ill cases with 1 death. Historically, other H5N1 strains have caused severe illness and high death rates in humans. Notably, H5N1 2.3.2.1c caused 4 illnesses (3 of them fatal) in Cambodia last year.
Person-to-person transmission of H5N1 is currently rare. [Strong evidence]
H5N1 does not have mutations that support easy person-to-person transmission. Between 2004 and 2007, there were rare non-sustained instances of human-to-human transmissions that most likely occurred between family members with prolonged close exposure to a sick individual. Those cases involved earlier strains. The current H5N1 2.3.4.4b strain did not emerge until 2020.
Over time, the virus may acquire mutations that make person-to-person transmission more efficient, reinforcing the need for effective interventions to control and monitor transmission in livestock, commercial flocks, and wild birds.
Human infection with this H5N1 is rare. [Not well investigated]
As of April 25, the CDC has tested 23 people for H5N1, is actively monitoring 44 people, and is passively monitoring additional people. Only one case has been detected.
Anecdotally, people in the bovine industry have observed sick people where there have been sick cows; however, it is also winter respiratory illness season, which may explain the illnesses. Because people are not regularly tested for H5N1, mild cases may have gone undetected.
H5N1 is susceptible to commercially available antiviral medicines used to treat seasonal influenza. [Strong evidence]
This week, the CDC concluded tests indicating that two classes of antiviral medications used to treat seasonal influenza are effective against H5N1. Neuraminidase inhibitors (e.g., oseltamivir (Tamiflu®), zanamivir, and peramivir) and polymerase inhibitors (e.g., baloxavir (Xofluza®)) can be used against H5N1. [Study results were shared at a symposium with PHC staff in attendance.]
The US maintains a Strategic National Stockpile (SNS) of several medications, including all the antivirals discussed above. These tens of millions of courses of antivirals can be used to supplement commercial sources and alleviate supply chain issues should they arise. No supply chain issues have been noted so far for these antiviral medications. During the 2022-2023 flu season, the early peak caused spot shortages, and the SNS remedied the deficit. If needed for H5N1, the SNS could follow the same operational plan used for that shortage.
Existing processes and manufacturing platforms can be used to jumpstart the development of a vaccine for H5N1 if needed. [Strong evidence]
Vaccination of humans against H5N1 is not a tool that is required at this time, but the preparedness steps are in place to develop vaccines and plans for administration. The CDC constantly monitors for emerging types of influenza. When they identify viruses that are sufficiently new or concerning in any way, they create candidate vaccine viruses. These are blueprints for a potential vaccine target. The National Pre-pandemic Influenza Vaccine Stockpile (NPIVS) program takes these candidates and completes the initial manufacturing of a potential vaccine. Completing this process before the vaccine is needed allows them to address manufacturing issues and build an initial vaccine supply. NPIVS also stockpiles other components of the vaccines to allow for rapid manufacturing.
Two H5N1 candidate vaccine viruses are well matched to the H5N1 in dairy cattle. NPIVS has completed an initial fill of some vaccine doses and is evaluating the appropriate regulatory pathway for use if they are needed for response. These hundreds of thousands of doses would be the initial rollout. A second wave would use stockpiled components to create up to 10 million doses. If more doses are needed, existing US government contracts with manufacturers would be leveraged for large-scale manufacturing. The current preparedness is covered as normal activities in the US budget; switching to a response posture would require additional funding from Congress.
PHC predicts restrictions on and testing requirements for dairy cattle movement will continue to evolve. [High confidence]
Numerous US states have restricted cattle imports from states with H5N1 outbreaks. USDA will require dairy cattle to have a negative Influenza A result for interstate travel. As of April 5, The World Organisation for Animal Health (WOAH) did not recommend import restrictions on cattle or dairy products. WOAH recommendations have wide-reaching impacts. All countries that are members of the World Trade Organization agree to abide by WOAH assessments regarding import restrictions. An import risk analysis must be conducted according to WOAH Terrestrial Animal Health Code Chapter 2.1. Despite this requirement, on April 25, Colombia became the first country to restrict US beef exports.
Actions your business can take now:
Review your pandemic plan NOW, before there is an emergency.
The outbreak of H5N1 in dairy cattle serves as a reminder that new infectious disease outbreaks are inevitable. Companies should plan to review their pandemic plans yearly and when potential threats emerge. Ensure that personnel information reflects changes due to staff turnover or contact information changes. Be clear on how decisions will be made regarding office closures, changes to remote work policies, cleaning schedules, and provision of supplies like hand sanitizer and masks.
Evaluate planning for flu vaccine clinics on site in the fall.
On-site flu shot clinics reduce barriers to employees getting annual vaccinations for seasonal flu. Last year, some employers reported difficulty securing practitioners for on-site flu clinics. Early contracting with these clinics can help ensure your employees are protected against seasonal influenza. If H5N1 evolves to spread easily between humans, an additional flu vaccine may be developed (as happened in 2010 during the H1N1 pandemic). On-site flu clinics could be used to provide both seasonal and H5N1 vaccines if warranted.
Maintain or establish a work culture that supports employees’ decisions to wear masks.
Masks can be effective at preventing influenza and other infections. Individuals who are vulnerable or who have vulnerable family members may prefer to wear masks to reduce the risk of numerous airborne infections. A work culture that supports those decisions can make it easier for other employees to add this layer of protection if the risk rises. Reducing infections protects workers’ health, reduces absenteeism, and can reduce employer health insurance costs.
Assess the budget for items like cleaning supplies and hand sanitizer to avoid unexpected costs. Plan to restock early to avoid any shortages that develop.
The current situation is not a crisis; businesses should not overinvest in stockpiling. Nevertheless, the current outbreak introduces uncertainty around the demand for these products, and businesses should consider the cost of additional storage versus potential future order delays. Increasing the cadence for reviewing purchasing schedules may suffice during this early stage.
Businesses that provide food services should plan for the price of milk and eggs to fluctuate when developing budgets.
H5N1 outbreaks in US poultry have repeatedly resulted in significant losses of commercial poultry. The culling of egg-laying flocks has previously driven egg prices to record highs. The spring avian influenza season is starting, and egg prices are currently up 16% from January. Numerous industry publications predicted egg prices would not climb above 2023 prices, but avian influenza impacts remain unpredictable.
By comparison, infected dairy cattle appear to fully recover after about two weeks, a limited period of the cow’s overall milking days. Currently, the outbreaks are too limited to impact the availability of milk in the US. Cattle live longer and are far more expensive than poultry. Therefore, culling will not be an initial step in control. Mandatory testing or other interventions may add costs to milk production that are eventually passed down to the consumer (although USDA APHIS will compensate farmers for the cost of H5N1 testing for diagnostics or travel if performed at a National Animal Health Laboratory Network lab). Consumer reaction to the discovery of H5N1 genetic material in grocery store milk may have a larger impact on the industry.
References:
- https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock
- https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/usda-publishes-h5n1-influenza-virus-genetic
- https://twitter.com/MichaelWorobey/status/1782756133402509587
- https://twitter.com/LouiseHMoncla/status/1783555179180356093
- https://www.fda.gov/food/alerts-advisories-safety-information/updates-highly-pathogenic-avian-influenza-hpai
- https://www.science.org/content/article/u-s-government-taking-action-stop-cow-flu-it-too-little-too-late
- https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=131.3
- https://pubmed.ncbi.nlm.nih.gov/32650645/
- https://www.cdc.gov/flu/avianflu/spotlights/2022-2023/h5n1-technical-report_october.htm
- https://www.cdc.gov/flu/avianflu/spotlights/2022-2023/h5n1-technical-report_october.htm
- https://www.bovinevetonline.com/news/industry/message-ag-industry-about-h5n1
- https://aspr.hhs.gov/SNS/Pages/Access-to-Influenza-Countermeasure.aspx
- https://medicalcountermeasures.gov/barda/influenza-and-emerging-infectious-diseases/pandemic-vaccines-adjuvants/
- https://www.avma.org/news/states-begin-restrict-cattle-imports-those-influenza-cases
- https://www.usda.gov/media/press-releases/2024/04/24/usda-actions-protect-livestock-health-highly-pathogenic-h5n1-avian
- https://www.woah.org/en/high-pathogenicity-avian-influenza-in-cattle/
- https://www.wto.org/english/thewto_e/coher_e/wto_oie_e.htm
- https://www.reuters.com/markets/commodities/colombia-becomes-first-country-restrict-us-beef-due-bird-flu-dairy-cows-2024-04-25/
Confidential and Proprietary
PHC Global provides this material for informational purposes only. It does not constitute, and is not a substitute for, medical services or advice and should not be construed as such.
SHOW LESSInfluenza viruses, including H5N1, are notorious for their constant evolution. Although the H5N1 2.3.4.4b strain currently poses little risk of person-to-person transmission, that could rapidly change....SEE MORE
Influenza viruses, including H5N1, are notorious for their constant evolution. Although the H5N1 2.3.4.4b strain currently poses little risk of person-to-person transmission, that could rapidly change. It would only take the wrong cow to meet the wrong bird for the virus to morph into one that could cause more severe disease symptoms or become more transmissible. That ability to easily pick up new genetic characteristics is why influenza constantly ranks as having the highest pandemic potential and why businesses need H5N1 on their radar.
Influenza is particularly good at traveling the globe.
Genomic sequencing indicates that an initial H5N1 spillover from birds to several dairy cattle herds. Movement of cattle with undetected infections spread H5N1 to other farms. After this introduction into dairy cows, spillback into migratory birds—or wild mammals—could cause the dairy cattle H5N1 strain to spread further within the United States or beyond its borders.
These concerns aren’t overblown. Migratory birds have spread earlier versions of H5N1 along their flyways, allowing new viruses to travel the world within two years.
Movement of dairy cattle can introduce the virus to new farms, even with the new Federal testing requirements for cattle. Once the infection is introduced to a farm, H5N1 can quickly spread among dairy cows, likely through contaminated milking equipment. H5N1 infection in cows is mild; the most pronounced symptom is a temporary reduction in milk production. However, H5N1 has caused significant illness–and high rates of mortality–in other mammals. An earlier version of H5N1 had a ~50% mortality rate in humans.
What happens on the farm doesn’t stay on the farm. Agriculture impacts ripple globally.
Given the potential economic impact of H5N1 on milk production and operational costs, it’s only natural that it is top of mind for agricultural businesses.
However, enterprise businesses outside the agricultural sector are also exposed to risks. Most immediately, enterprise businesses—including those outside the United States—purchasing poultry or cattle products (eggs, dairy, beef, etc.) should prepare for price fluctuations.
Influenza viruses constantly evolve, and these shifts can happen quickly. In an ever-changing—and mutating—landscape, staying ahead of risks is more important than ever. PHC Global’s Pharos early warning system empowers subscribers to stay ahead of the curve and effectively manage risks before a significant disruption occurs.
Don’t let the next biological threat compromise your business continuity. Sign up for a free trial of PHC Pharos today and equip your business with the tools needed for an ever-changing world, so you can protect your people, assets and revenue.
SHOW LESSWhat is the Milk Warning Us About? H5N1 in dairy cattle is a wake-up call to CSOs. COVID may feel over, but new disruptive biosecurity threats are constantly emerging. Last week, we told you the milk isn’t the threat—it’s the warning....SEE MORE
What is the Milk Warning Us About?
H5N1 in dairy cattle is a wake-up call to CSOs. COVID may feel over, but new disruptive biosecurity threats are constantly emerging. Last week, we told you the milk isn't the threat—it's the warning. If H5N1 evolves dangerously, the CSO role will once again be responsible for the company response plan, but the knock-on effects of biosecurity threats can be hard to anticipate. This week, we walk you through three possible and highly disruptive H5N1 scenarios: the agricultural disaster, the moderate pandemic, and the severe pandemic. These scenarios are valuable for shaping preparedness strategies and highlighting biologically possible outcomes but are not intended as near-term predictions.
Scenario #1 Massive Agricultural Disruption
In Scenario #1, H5N1 evolves to massively disrupt agriculture by causing severe disease in dairy or beef cattle or by asymptomatically infecting humans who could unintentionally spread the virus throughout commodity operations (cattle or poultry). The consequences of an H5N1-driven catastrophic agricultural disease would be extensive. Initially, commodity prices would rise dramatically; those costs would then ripple through the US economy. The food industry, grocery stores, restaurants, and anywhere serving food (including public schools and hospitals) would feel the brunt of food scarcity and high prices. How would your food services team adapt? Will there be cost overruns?
A devastating agricultural H5N1 would trigger an international response. Although World Trade Organization member countries are required to justify trade restrictions due to disease, fear could trigger highly reactive import bans. Even if the World Organization for Animal Health (the designated adjudicator of animal disease-related embargos) eventually found import restrictions could not be justified, the impact on U.S. markets would be massive. Agriculture, food, and related industries contribute 5.6% of the US GDP and employ 10.4% of US workers. 2023 US export values included $9.97B (beef), $8.01B (dairy), $5.49B (poultry), and $760M (eggs).
Scenario #2 A Moderate Pandemic – H1N1 Redux
In Scenario #2, H5N1 acquires the ability to be transmitted between people. Influenza viruses have two protein spikes on their outer layer: the H in H5 and the N in N1. Pandemic influenza viruses have novel spike proteins that our immune systems haven’t seen before. That universal lack of past exposure through infection and vaccine means essentially all people are susceptible to the new virus. Current seasonal influenza vaccines cover an H3N2 and an H1N1 (along with two influenza B viruses); the H5 would be entirely new.
Pandemic severity reflects the transmissibility and severity of illness. In Scenario #2, H5N1 would echo the 2009-2010 H1N1 swine flu pandemic, which was moderately infectious and moderately severe. To imagine the company impacts of this scenario, CSOs can review the impacts that moderate biosecurity threats (e.g., H1N1 or Zika) had on their operations and assess what new options exist today. Key questions include:
- What departments or roles had the greatest excess absenteeism or reduced productivity? What were the challenges faced in 2009-2010, and were they fully addressed during COVID-19, or do you need to find solutions? Where hybrid isn’t an option, did reduced customer demand match absenteeism impacts?
- Did your business host flu vaccine clinics onsite to lower barriers to employees getting the extra flu shot? H1N1 got a separate vaccine from seasonal flu that year. The same thing could happen if H5N1 evolves. Reducing infections can limit productivity losses, reduce absenteeism, and save on health insurance premiums.
- Are your business continuity plans up to date, to include lessons learned? Do they reflect the current organizational structure and identify the correct decision makers?
Scenario #3 A Severe Pandemic – H5N1 Goes Person-to-Person and Regains Previous Severity
In this darkest scenario, a severe H5N1 pandemic spreads easily between people and regularly causes severe disease. An earlier strain of H5N1 killed about 50% of identified human cases. Even if H5N1 didn’t kill half of the people infected, a plausible worst-case scenario could see rates much higher than the 8.7% case fatality rate that COVID averaged in studies conducted during the first year of the pandemic. This severe influenza pandemic would be COVID on steroids.
No pandemic looks exactly like the previous pandemic, but the experience of decision makers can be invaluable in tackling a new crisis. Before staff turnover cements a complete loss of institutional knowledge, CSOs should document not just the decisions made during past pandemics but also the challenges and the considerations. A playbook that dictates if X then Y will rapidly fall short. Instead, CSOs should record the decision-making processes, criteria, considerations, and ripple effects. Lessons learned should not focus on the specific tactical solution selected but rather on how leaders successfully understood the problem and strategically planned for it.
Waiting to develop a plan is too risky for today's conditions. These scenarios require thoughtful consideration and planning to ensure your business weathers any possible disruption. PHC Global understands businesses need early warning on both tactical and strategic intelligence. We combine expertise, data, and technology to give you the insight you need now to ensure business continuity.
Sign up for a free trial of PHC Pharos today and equip your business with the tools needed for an ever-changing world, so you can protect your people, assets and revenue.
SHOW LESSBefore COVID-19, when pandemic experts imagined the next great threat, we always started with a novel influenza virus. Other diseases have also caused pandemics, but influenza is a constantly evolving and ever-present threat....SEE MORE
Before COVID-19, when pandemic experts imagined the next great threat, we always started with a novel influenza virus. Other diseases have also caused pandemics, but influenza is a constantly evolving and ever-present threat. Seasonal influenza viruses have slight changes that let them infect people year after year, but pandemics come from significant shifts in the virus. The 2009-2010 H1N1 pandemic was most recent, but the Great Influenza pandemic of 1918 is what we feared most – one-fifth of the world infected and 50 million dead, far more than the 16 million lives lost in World War I.
Flu viruses are excellent at picking up mutations. When two different viruses infect the same person or animal, they can exchange genetic material. The current H5N1 strain (H5N1 2.3.4.4b) can now infect a surprisingly wide variety of birds and mammals. While it is no longer as deadly in humans (the 50% fatality rate was seen earlier in different H5N1 strains), it has caused mass die-offs in sea lions and seals. The more it spreads in mammals, the more opportunities for a mutation that could enable it to cause severe disease in humans or allow for person-to-person transmission. The detection of H5N1 viral fragments in 1 out of 5 grocery store milk samples in many states indicates the virus is far more widespread than initially thought. As expected, gold-standard egg-inoculation tests have shown that pasteurization inactivates the virus. The milk isn’t the threat; it’s the early warning of what could happen.
For most enterprise businesses, the current situation is a straightforward, early signal of a potential disruptive threat. The virus may never evolve to transmit between people, but it has regularly surprised us. With COVID in the rear-view mirror for many, the current situation is a reminder that biosecurity threats will continue to emerge.
Businesses can take several actions now:
- Review your pandemic plan NOW, before an emergency: update personnel information and ensure designated decision-makers know their roles and decision criteria.
- Evaluate planning for flu vaccine clinics on site in the fall. If H5N1 evolves to spread easily between humans, an additional flu vaccine may be developed (as happened in the 2009-2010 H1N1 pandemic). On-site flu clinics could provide both seasonal and H5N1 vaccines if warranted.
- Encourage employees to stay home when sick and to work from home as appropriate. This practice prepares employees and IT teams for widespread remote or hybrid work, if necessary maintain or establish a work culture that supports employees’ choices to wear masks. An open environment makes it easier for other employees to add this layer of protection if the risk rises. Reducing infections protects workers’ health, reduces absenteeism, and can reduce employer health insurance costs.
- Maintain or increase the budget for cleaning supplies and hand sanitizer to avoid unexpected costs. Increase the cadence for reviewing purchasing schedules. An unpredictable future is not the time for “set it and forget it."
- Prepare for milk and egg price volatility when developing food service budgets. Mandatory testing or other interventions may add costs to milk production that are eventually passed down to the consumer.
Staying ahead of potential risks is more critical now than ever; that’s where PHC Pharos comes in. As a dedicated early warning system, PHC Pharos empowers subscribers with real-time intelligence and expert recommendations to navigate the complex biosecurity landscape effectively. It’s not simply managing potential risks; it’s about solutions and staying ahead of them.
Don’t wait for the next biological threat to disrupt your business continuity.
Sign up for PHC Pharos today and equip your business with the tools to stay one step ahead in an ever-changing world.
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