Avian Influenza A(H5) Outbreak | Center for Outbreak Response Innovation

Current US Outbreak

As of January 9, 2025:

Critical Updates:

The Louisiana Department of Health has reported the first H5N1-related death in the United States. The individual tested positive and was hospitalized in November with known risk factors, including age over 65, and reported preexisting conditions.
Genetic sequencing of the Louisiana mortality case conducted by the CDC indicates that the individual had several genetic mutations found in other severe H5N1 cases, one of which was the E186E/D mutation identified in the British Columbia severe case in late 2024 that is known to be associated with better binding to the human lung receptors. Genetic analysis of the two specimens collected from the Louisiana human case and the specimens from the wild birds in Louisiana and on the individual’s property indicate the mutation most likely arose during the course of human clinical infection. There is no evidence of human-to-human transmission currently.
Reports of H5N1 in domestic house cats are becoming common. Pet owners can take precautions by not feeding their animals raw food, being mindful to check for and remove any recalled contaminated food, limiting their pets’ exposure to wild birds or other outdoor flocks, and contacting their vets if they exhibit signs of illness (lethargy, loss of appetite, etc)

Routine Surveillance Updates

The Centers for Disease Control and Prevention (CDC) is reporting 66 confirmed human cases of H5 in the United States Outbreak as of January 9, 2024. Two of these cases have not had a known source of infection and reported no contact with animals or raw milk, while 23 have had contact with poultry, 40 have had contact with dairy cows, and one had exposure to a backyard flock.
CDC reports that for the duration of the outbreak, 160 tests have been conducted for individuals with exposure to dairy cows and 400 tests have been conducted for individuals exposed to birds and other animals, resulting in a positivity rate since March 2024 of 25.00% (40/160), 5.75% (23/400) respectively.
The United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) has reported 151 new infected cattle herds across three states (CA, TX, MI) in the last 30 days, bringing the total for the outbreak to 923 cattle herds in 16 states.