On January 6, a Louisiana resident died from bird flu after exposure to an infected backyard flock, becoming the U.S.’s first human bird flu death. The person was 65+ with underlying medical conditions. Samples of the bird flu virus from the patient showed mutations from the backyard flock, which likely contributed to more severe illness. There is currently no evidence of human-to-human transmission, and the risk to the public remains low.

Genetic testing showed that the genotype of the virus the person was infected with was D.1.1, which is related to other D.1.1 genotypes spreading in wild birds and poultry. This is a different type from the B3.13 genotype currently spreading in dairy cows and some poultry flocks. 

The D.1.1 genotype also caused severe disease in a teenager in British Columbia and is linked to several mild cases in Washington State.

Mutations in the virus likely increased the virus’ ability to attach to the human respiratory tract. This mutation was also seen in the severe case of bird flu in Canada.

No person-to-person transmission has been identified, and this is the only human case of bird flu reported in Louisiana as of 1/10/25. The risk to the public remains low.

People who have contact with wild or farm animals, especially poultry, cattle, or wild birds should take precautions to protect themselves. More information for backyard chicken flock owners can be found here, and for hunters here.

Public health and government officials continue to monitor cases of H5N1 or bird flu and genetically sequence human cases for any signs of virus mutations. These mutations could result in increased transmission between humans, increased resistance to vaccines, or reduced susceptibility to antiviral drugs.