NACCHO is closely monitoring news and information related to avian influenza A(H5N1) (bird flu) and is ready to assist and support local health departments with response as needed. To follow are recent updates and resources regarding bird flu. NACCHO will update this blog post as needed and share information via its Virtual Communities platform. If your health department needs support or has questions, please reach out to NACCHO’s Preparedness team.

Recent Updates:

February 24, 2025: CDC A(H5N1) Bird Flu Response Update

As part of a February 24 bird flu response update, CDC noted that it has confirmed three human cases of H5 bird flu in people who became ill in 2025: a dairy worker with exposure to infected dairy cows (Nevada), a poultry worker with exposure to infected commercial poultry (Ohio), and the owner of an infected backyard poultry flock (Wyoming). These are all considered higher-risk exposures. To date, person-to-person spread of H5 bird flu has not been identified. CDC believes the immediate risk to the general public from H5 bird flu remains low but this risk assessment could change as influenza viruses constantly change.

February 20, 2025: CDC MMWR: Highly Pathogenic Avian Influenza A(H5N1) Virus Infection of Indoor Domestic Cats Within Dairy Industry Worker Households — Michigan, May 2024

In an MMWR released on February 20, CDC shared results of a study showing two indoor-only cats living in separate households in Michigan developed H5N1 bird flu in May 2024 and subsequently died. The cats’ owners were dairy farmworkers who declined testing but reported having symptoms consistent with H5N1 bird flu prior to the cats becoming ill. Ultimately, investigators could not confirm how the cats became infected. CDC experts are tracking the spread and impact of avian influenza A(H5N1) viruses among animals and to people in the United States in order to inform guidance on how to best prevent and treat infections.

January 16, 2025: CDC Recommends Hospitals Accelerate H5N1 Testing

CDC has released a Health Alert Network (HAN) Health Advisory recommending that hospitals expedite H5N1 avian flu testing for patients with influenza. This alert comes amid the current H5N1 outbreak among U.S. dairy cows and poultry and high seasonal rates of influenza. The CDC states that patients hospitalized with influenza A should be tested for avian flu within 24 hours, especially individuals in the intensive care unit (ICU). This recommendation would not increase the volume of subtyping but accelerates the process to ensure a timely response to the avian flu. The CDC maintains that the risk to the public for the H5N1 avian flu is low.

January 6, 2025: First H5 Bird Flu Death Reported in United States

Louisiana has reported that a person previously hospitalized with severe avian influenza A(H5N1) illness (“H5N1 bird flu”) has passed away. While tragic, a death from H5N1 bird flu in the United States is not unexpected because of the known potential for infection with these viruses to cause severe illness and death. As of January 6, 2025, there have been 66 confirmed human cases of H5N1 bird flu in the United States since 2024 and 67 since 2022. This is the first person in the United States who has died as a result of an H5 infection. CDC has carefully studied the available information about the person who died in Louisiana and continues to assess that the risk to the general public remains low. Most importantly, no person-to-person transmission spread has been identified.

December 18, 2024: CDC Confirms First Severe Case of H5N1 Bird Flu in the United States

CDC has confirmed that a patient has been hospitalized with a severe case of avian influenza A(H5N1) virus infection in Louisiana. This marks the first instance of severe illness linked to the virus in the United States. While an investigation into the source of the infection in Louisiana is ongoing, it has been determined that the patient had exposure to sick and dead birds in backyard flocks. This is the first case of H5N1 bird flu in the U.S. that has been linked to exposure to a backyard flock.

December 6, 2024: USDA Implements Testing of Milk Supply for Bird Flu 
USDA issued an order mandating raw milk testing as part of the federal government’s comprehensive surveillance efforts related to avian flu. This mandate comes amid an outbreak that has affected over 700 herds of dairy cows across many states. An initial round of testing is set to begin next week in raw milk from milk silos at dairy processing facilities. After that, USDA will implement bulk milk testing programs as needed, which will help to identify specific herds that are impacted by avian flu. 

November 22, 2024: CDC confirms H5N1 Bird Flu Infection in a Child in California

CDC has confirmed a human infection with H5N1 bird flu in a child in California. This is the first reported avian influenza H5 virus infection in a child in the United States. CDC’s risk assessment for the general public is low. However, people with exposure to infected or potentially infected animals, such as birds, dairy cattle, or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at higher risk of infection. CDC recommends avoiding unprotected exposures to sick or dead animals, including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cows).

November 8, 2024: CDC Expands H5N1 Bird Flu Guidance to Better Protect Farm Workers

CDC updated its guidance for Highly Pathogenic Avian Influenza A(H5N1) Virus: Interim Recommendations for Prevention, Monitoring, and Public Health Investigations following a recent study published in the MMWR that reveals important findings about H5N1 virus exposure among farm workers in Michigan and Colorado. This study builds on earlier findings reported in July and underscores the need for enhanced protective measures for farm workers to prevent H5N1 transmission from infected animals.

Resources

• CDC: Primary page linking to current information and resources
• CDC: Comprehensive collection of materials and tools to help educate and inform the public about H5 bird flu, including fact sheets, posters, and infographics
• CDC: Wastewater surveillance for bird flu
• FDA: Investigation of Avian Influenza A (H5N1) Virus in Dairy Cattle
• Public Health Communications Collaborative: Sample messaging for use in sharing information