January 23, 2025
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Latest information on avian influenza in humans, cats, and chickens
H5N1 avian influenza continues to spread among commercial and backyard poultry, with additional cases reported in domestic cats
As the avian influenza outbreak affecting poultry, dairy cattle and humans in the U.S. continues to make headlines, here’s what you need to know about the situation as of January 23.
human cases
The United States reported its first human case of H5N1 avian influenza in two years in April 2024. Since then, the Centers for Disease Control and Prevention has reported a total of 67 confirmed human cases. The first death from avian influenza in the United States was announced in Louisiana earlier this month, but most human infections in the country have remained extremely mild.
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The CDC maintains there is no evidence of human-to-human transmission. Most people with avian influenza are infected through contact with sick dairy cows or poultry. Cows infected with avian influenza excrete large amounts of the H5N1 virus into their milk, but it has been confirmed that pasteurization kills the virus, making commercially available milk safe to drink. (Raw milk is not safe.) Poultry workers are infected primarily through slaughtering operations. The source of some human infections remains difficult to identify.
poultry case
Avian influenza continues to spread among commercial and backyard poultry. As of Jan. 23, the U.S. Department of Agriculture reported 98 infected flocks in the past 30 days, affecting more than 15 million birds. Avian influenza is highly contagious and deadly to poultry, so entire flocks are culled as soon as the presence of the virus is confirmed. Since the avian influenza outbreak began in February 2022, more than 140 million birds have been infected or actively culled.
Recent poultry infections include two large commercial poultry farms in Georgia that are important sources of so-called broilers raised for meat. Maryland and Virginia have also reported recent cases at broiler facilities, and Missouri has confirmed avian influenza cases at egg farms. And New York state health officials announced an outbreak at a duck farm on Long Island. Egg prices are rising rapidly as cases of bird flu are on the rise. Fortunately, although eggs can carry many infectious diseases and should never be eaten raw, you are unlikely to catch avian influenza from commercial chicken eggs.
cat case
Recently, a number of cases of avian influenza have been detected in domestic cats. Positive samples were taken in California, Kansas, Louisiana and Iowa in January, and several more cases from December were confirmed this month. There is usually little information available in these cases, and there are several ways cats can become infected with avian influenza. Cats in dairy farms are particularly susceptible. Such cats can become infected by drinking milk from sick cows. However, cats who are outdoors can also catch avian influenza from wild birds. Indoor cats can also be exposed to the virus through raw milk and raw food. Recognizing this last threat, the Food and Drug Administration on January 17 ordered raw pet food manufacturers to update their food safety plans to include H5N1.
federal communications
Surveillance of avian influenza has been a challenge since it first entered North America, likely through wild birds outside the jurisdiction of specific health agencies. And while poultry farmers have extensive experience with avian influenza and strict biosecurity protocols, experts don’t expect the virus to jump to dairy cows, which, like poultry, are under the jurisdiction of the Department of Agriculture and its state equivalents. I hadn’t. Local and state public health departments are responsible for human cases, with federal CDC coordination.
The inauguration of President Donald Trump further clouded the situation. The administration has ordered the Department of Health and Human Services, including the CDC, to suspend all public communications until at least the end of the month.
