H5N1 Response

This webpage is updated regularly with information regarding the current outbreak of highly pathogenic avian influenza (HPAI or H5N1). WCMA members with questions may contact WCMA Executive Director John Umhoefer or WCMA Senior Director of Programs & Policy Rebekah Sweeney.

Latest Updates

September 3:

• Cows at three dairy farms in California's Central Valley have tested positive for highly pathogenic avian influenza (H5N1), the California Department of Food and Agriculture said late last week. The three farms have been quarantined, and no human cases of H5N1 have been detected in connection with these new positives. Officials reiterated that there remains no threat to the commercial milk supply.
• U.S. Department of Agriculture (USDA) Secretary Tom Vilsack has authorized the first field safety trials of an H5N1 vaccine for dairy cattle. Vilsack said USDA's Center for Veterinary Biologics is overseeing the effort, which is the next step in the process of developing a vaccine that may eventually be widely available to dairy producers.

August 19:

• In a letter sent last week, the U.S. Food and Drug Administration (FDA), National Conference on Interstate Milk Shipments (NCIMS), and U.S. Department of Agriculture (USDA) asked State Departments of Agriculture to engage in a voluntary six-week silo sampling study to determine the prevalence of H5N1 in raw milk at dairy processing facilities. WCMA staff are engaged with federal and state officials to better understand this voluntary effort.

August 13:

• The U.S. Food and Drug Administration (FDA) today released the results of its second retail sampling survey of retail dairy products. This survey tested 167 dairy products collected at retail locations for highly pathogenic avian influenza A (H5N1). The samples included aged raw milk cheese as well as pasteurized fluid milk and products made from pasteurized milk, such as pasteurized cheeses, cream cheese, butter, ice cream. No viable H5N1 virus was detected in the products.
• Click to download WCMA's FREE template: H5N1 On-Farm Response Standard Operating Procedure (SOP)
• Midwestern dairy farmers can apply now at WisCheeseMakers.org for reimbursement grants of up to $10,000 each to support on-farm biosecurity efforts amid the ongoing outbreak of highly pathogenic avian influenza (H5N1) in dairy cattle. Total pilot program funding of $100,000 is available on a first-come, first-served basis through the Dairy Business Innovation Alliance (DBIA), a partnership between WCMA and the Center for Dairy Research (CDR). 

Free WCMA Webinars & Workshops

Free Templates

• H5N1 On-Farm Response Standard Operating Procedure (SOP)
• Signage (click to download PDFs):
  • Do Not Enter: Find Secure Entry Point
  • Do Not Enter: Milk Collection in Progress
  • Biosecure Entry Point
  • PPE Required for Access
  • Boot Sanitizing or Covers Required
  • All Staff and Visitors Must Wash Hands and Wear Clean Gloves
  • Employee and Visitor Parking

All signs can be printed on corrugated plastic and distributed with help from WCMA, thanks to funding from the Dairy Business Innovation Alliance. Contact WCMA Communications Director Grace Atherton to request signs.

Federal and State Resources

• Centers for Disease Control and Prevention (CDC)
• Food and Drug Administration (FDA)
• U.S. Department of Agriculture (USDA)
• Wisconsin Department of Agriculture, Trade and Consumer Protection (WDATCP)

WISCONSIN DEPARTMENT OF HEALTH SERVICES (WDHS) REQUEST FOR PPE

WDHS DAIRY PROCESSING FACT SHEET (ENGLISH)

WDHS DAIRY PROCESSING FACT SHEET (SPANISH)

University of Wisconsin: Signs of On-Farm Stress & Response Resources

UW Extension: Supporting Farmer Mental Health and Well-Being

Prevention Measures for Dairy Processing Personnel

In direct conversation with WCMA staff, the CDC confirmed its recommendation that anyone working with confirmed affected or potentially affected raw milk - which means all raw milk - wear personal protective equipment (PPE). This includes dairy haulers and dairy processing personnel involved in raw milk handling. Risk levels can be estimated using using CDC's Risk by Exposure Table.

Recommended PPE for employees working with raw milk includes a NIOSH Approved® particulate respirator (for example an N95® or greater filtering facepiece respirator), eye protection, and gloves. They must also thoroughly wash their hands after raw milk contact.

To support Wisconsin dairy processors' and farmers' efforts to keep their employees safe, the Wisconsin Department of Health Services (WDHS) is making PPE available to Wisconsin dairy processors free of charge. Requests for supplies can be submitted at https://www.dhs.wisconsin.gov/preparedness/medical-stockpile.htm

WDHS has also created a new fact sheet (available in English and Spanish) to help support dairy processors' efforts to keep their valued employees safe during the current outbreak of H5N1 in dairy herds. This free resource, created with input from WCMA, offers safety tips on key topics including personal protective equipment, pasteurization, and disinfecting protocols.

U.S. Senator Tammy Baldwin (D-WI) has appealed for H5N1 aid specifically for dairy processors.

CDC officials note that workers should receive training on the use of PPE, including how to properly put it on, take it off, dispose of it, and maintain it. The Environmental Protection Agency (EPA) maintains a list of registered antimicrobial products that are effective against HPAI.

Background: HPAI/H5N1 in Dairy Herds

Highly pathogenic avian influenza (HPAI) is widespread among wild birds in the U.S. and globally. The virus has also caused outbreaks in commercial and backyard poultry flocks, and sporadic infections in mammals. A study published by Cornell University in July 2024 showed evidence of "sustained and efficient" spread of bird flu between cows and from cows to other mammals. Researchers say that while the study indicates that the virus could continue to adapt in mammals, genome sequencing did not reveal any mutations in the virus that would lead to enhanced transmissibility of H5N1 in humans.

H5N1 in dairy cows was first reported by USDA on March 25, 2024. Unpasteurized milk from sick cattle collected from two dairy farms in Kansas and one in Texas, as well as a throat swab from a cow in another dairy in Texas, tested positive.

Outbreaks of H5N1 have now been confirmed in 178 dairy herds in Colorado, Idaho, Iowa, Kansas, Michigan, Minnesota, New Mexico, North Carolina, Ohio, Oklahoma, South Dakota, Texas,l and Wyoming.

USDA’s Animal and Plant Health Inspection Service notes, at this stage, no anticipation of a need to depopulate dairy herds. Unlike the illness in birds, which is typically fatal, little to no mortality has been reported among dairy cows and the affected animals are reportedly recovering while being isolated from other animals.

H5N1 symptoms in dairy cattle can include any of the following: a sudden drop in milk production; production of thicker, more concentrated, colostrum-like milk; drop in feed consumption with a simultaneous drop in rumen function; loose feces and some fever; pneumonia and mastitis.

Officials are strongly advising dairy producers to use all standard biosecurity measures, noting the importance for producers to clean and disinfect all livestock watering devices and isolate drinking water that could be contaminated by waterfowl.

Beginning April 29, USDA has also required, via Federal Order:

• Mandatory Testing for Interstate Movement of Dairy Cattle
  • Prior to interstate movement, dairy cattle are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory. Owners of herds in which dairy cattle test positive for interstate movement will be required to provide epidemiological information, including animal movement tracing. Dairy cattle moving interstate must adhere to conditions specified by APHIS.  Note: These steps will be immediately required for lactating dairy cattle, while these requirements for other classes of dairy cattle will be based on scientific factors concerning the virus and its evolving risk profile.
• Mandatory Reporting
  • Laboratories and state veterinarians must report positive Influenza A nucleic acid detection diagnostic results (e.g. PCR or genetic sequencing) in livestock to USDA APHIS. Laboratories and state veterinarians must report positive Influenza A serology diagnostic results in livestock to USDA APHIS.

Related guidance is available online. Beginning June 19, 2024, the Wisconsin Department of Agriculture, Trade and Consumer Protection will require dairy producers to test all lactating cattle for Influenza A prior to movement to fairs or exhibitions. In order to move lactating dairy cattle to fairs or exhibitions within the state, producers must receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network laboratory with samples collected no more than 7 days prior to movement to the fair or exhibition. 

Producers with concerns should reach out to their veterinarian, State Animal Health Official, and/or Area Veterinarian in Charge.

Zoonotic Transmission to Humans

The CDC human health risk assessment for H5N1 for the U.S. general population remains low. However, people with close or prolonged, unprotected exposures to infected animals are at greater risk of infection.

Four people have tested positive during the current outbreak, following exposure to infected dairy cattle, in Colorado, Michigan, and Texas. All individuals reported mild symptoms and have since recovered.

A previous human case occurred in 2022 in Colorado following close contact with infected poultry. That individual also reported mild symptoms and has recovered.

Prevention Measures for Farm Personnel

According to CDC’s interim recommendations, people should avoid unprotected exposures to sick or dead animals including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cattle), as well as with animal carcasses, raw milk, feces, litter, or materials contaminated by birds or other animals with confirmed or suspected HPAI (H5N1) virus infection.

Farmers should also note CDC recommendations specific to their operations:

• Farmers, workers, and responders should wear recommended personal protective equipment (PPE) such as an N95 filtering facepiece respirator, eye protection, and gloves, and perform thorough hand washing after contact with a sick or dead animal, feces or litter from potential infected animals.
• Workers should receive training on and demonstrate an understanding of when to use PPE; what PPE is necessary; how to properly put on, use, take off, dispose of, and maintain PPE; and PPE limitations.
• Employers subject to Occupational Safety and Health Administration (OSHA) regulations should comply with applicable standards as highlighted on the OSHA Avian Influenza – Standards page.

People exposed to H5N1-infected birds or other animals, including people wearing recommended PPE, should monitor themselves for new respiratory illness symptoms, including conjunctivitis (eye redness), beginning after their first exposure and for 10 days after their last exposure. Influenza antiviral post-exposure prophylaxis may be considered to prevent infection, particularly in those who had unprotected exposure to H5N1-virus infected birds or other animals.

People who develop any illness symptoms after exposure to H5N1-infected birds or other animals should seek prompt medical evaluation for possible influenza testing and antiviral treatment by their clinician or public health department. Symptomatic persons should isolate away from others, including household members, except for seeking medical evaluation until it is determined that they are not infected with H5N1.

Prevention Measures: Food Recommendations

According to FDA and USDA, the commercial milk supply is safe because products are pasteurized before entering the market.  In new research highlighted on April 23, FDA officials noted, “We have seen nothing that would change our assessment that the commercial milk supply is safe.” FDA notes pasteurization is “not expected to remove the presence of viral particles,” but fragments of the inactive virus pose no increased risk to human health.

Additional research released April 26, studying 297 samples of dairy products found in retail stores in 38 states, again confirmed milk safety, with no detection of live, infectious virus, due to pasteurization.

On May 1, FDA shared a further set of results from a national commercial milk sampling study underway in coordination with USDA. The study included 297 total retail dairy samples. New preliminary results of egg inoculation tests on a second set of 201 quantitative polymerase chain reaction (qPCR)-positive retail dairy samples, including cottage cheese and sour cream, in addition to fluid milk, show that pasteurization is effective in inactivating HPAI (H5N1). This additional preliminary testing did not detect any live, infectious virus. FDA has since provided additional information on this retail sample survey. The update, which includes a list of states where each milk sample was processed, sheds further light on the agency's sampling and analysis procedures but does not provide any new test results or guidance.

A UW-Madison study has found that pasteurization is 99.99 percent effective in inactivating the H5N1 virus in milk, supporting the belief that the commercial milk supply remains safe.

Dairies are required to send only milk from healthy animals into processing for human consumption; milk from impacted animals is being diverted or destroyed so that it does not enter the human food supply. In addition, pasteurization has continually proven to inactivate bacteria and viruses, like influenza, in milk. Pasteurization is required for any milk entering the commercial food supply chain. 

Effective July 22, 2024, Colorado agriculture officials are requiring all licensed dairy farms in the state to submit milk samples weekly to be tested for the virus. Though pasteurization has proven extremely effective in inactivating the H5N1 virus in milk, Colorado leads the nation in human cases of H5N1, including several new cases in poultry farmworkers.

FDA’s longstanding position is that unpasteurized, raw milk can harbor dangerous microorganisms that can pose serious health risks to consumers, and FDA is reminding consumers of the risks associated with raw milk consumption in light of the HPAI detections. On June 6, FDA issued a letter to all state, territorial, and tribal partners offering recommendations regarding the sale and consumption of raw milk amid the H5N1 outbreak. 

Specifically regarding raw milk cheese, the FDA has said, "Because of the limited information available about the transmission of HPAI (H5N1) in raw milk, the FDA recommends that industry does not manufacture or sell raw milk or raw milk cheese products made with milk from cows showing symptoms of illness, including those infected with avian influenza or exposed to those infected with avian influenza."