Wisconsin Cheese Makers Association Logo

HPAI H5N1 Response

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

IMPORTANT NOTE: Pasteurization and heat treatment are highly effective in inactivating the H5N1 virus in milk. Researchers and officials maintain that the commercial milk supply is safe for consumers.

CDC Recommendation: PPE Requirements for Employees Interacting with Raw Milk

The CDC recommends that anyone working with raw milk, including dairy haulers and processing personnel, wear the following personal protective equipment:

Required PPE Notes
N95 or higher filtering facepiece respirator (NIOSH Approved®) Must be properly fitted
Eye protection Safety glasses or goggles
Gloves Disposable, changed between tasks
Thorough handwashing Required after any raw milk contact

Workers should receive training on how to properly put on, use, and remove PPE. The Environmental Protection Agency (EPA) maintains a list of registered antimicrobial products effective against HPAI.

Free WCMA Webinars & Workshops

Webinar / Workshop Date Recording & Materials
HPAI & employee safety
CDC guests Dr. Carrie Reed & Dr. John Gibbins discuss PPE strategies for dairy processors.		 July 30, 2024 ▶ View recording
↓ Presentation (PDF)
HPAI food safety research & regulatory updates
FDA guest Dr. Steven Grube discusses food safety research and regulatory updates.		 August 6, 2024 ▶ View recording
↓ Presentation (PDF)
Enhancing on-farm biosecurity amid HPAI
WDATCP's Karen Endres shares strategies for on-farm biosecurity and farmer mental health resources.		 August 13, 2024 ▶ View recording
↓ USDA slide deck (PDF)
↓ Biosecurity plan template (PDF)

These sessions were made possible in part by support from the Dairy Business Innovation Alliance, a partnership between WCMA and the Center for Dairy Research.

Free Templates: SOP & Signage

Downloadable On-Farm SOP:

Downloadable Biosecurity Signage (click to download PDFs - can be printed on corrugated plastic; contact Grace Atherton to request printed copies):

↓ 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

Federal & State Resources

Agency Resource
CDC H5N1 situation summary
FDA HPAI updates (includes latest dairy product testing results)
USDA HPAI detections in livestock | National Milk Testing Strategy
WDATCP Avian influenza in cattle (includes free PPE request form)
WDHS Dairy processing fact sheet (English) | Dairy processing fact sheet (Spanish)
UW–Madison Signs of on-farm stress & resources | Supporting farmer mental health and well-being

Background & Technical Detail

H5N1 was first confirmed in U.S. dairy cattle on March 25, 2024, and has since been confirmed in herds across 20 states. Symptoms in dairy cattle can include a sudden drop in milk production, production of thicker colostrum-like milk, reduced feed consumption, loose feces, fever, pneumonia, and mastitis. USDA required mandatory Influenza A testing for dairy cattle prior to interstate movement beginning April 29, 2024. In December 2024, USDA launched the National Milk Testing Strategy, requiring raw milk samples nationwide to be collected and tested for H5N1. In September 2024, USDA authorized the first field safety trials of an H5N1 cattle vaccine; that process is ongoing.
All individuals who have tested positive for H5N1 following exposure to infected dairy cattle reported mild symptoms and have since recovered. The CDC assesses the risk to the general U.S. population as low. People with close or prolonged, unprotected exposures to infected animals face a higher risk. People exposed to infected animals — even while wearing PPE — should monitor themselves for new respiratory symptoms for 10 days after their last exposure. Anyone who develops symptoms should seek prompt medical evaluation. CDC interim recommendations →
In January 2025, FDA began collecting 300 samples of aged raw milk cheese (aged 60+ days) from warehouses and distribution hubs nationwide. No viable H5N1 virus has been detected in any retail dairy products tested to date. FDA will not require any action solely in response to a PCR-positive result; viability testing is required before any follow-up action is considered. FDA testing updates →
A UW–Madison study found that pasteurization is 99.99% effective in inactivating H5N1 in milk. Additionally, FDA has conducted retail surveys on hundreds of products and detected no viable virus. In March 2025, FDA published findings from a Cornell University study showing that H5N1 virus could remain stable in raw milk cheese throughout the minimum required 60-day aging period. However, the study importantly found that the virus' survival was pH-dependent, and that heat treatment of raw milk 54°C (130°F) for at least 15 minutes or 60°C (140°F) for at least 10 seconds inactivated the virus. Throughout the outbreak, researchers and officials have maintained that the commercial milk and dairy product supply is safe for consumers.