A patient has been hospitalized with a severe case of avian influenza A(H5N1) virus infection, also known as the H5N1 Bird Flu, in Louisiana. This is the first instance of severe illness linked to the virus in the United States. The case was confirmed by the Centers for Disease Control and Prevention (CDC) on Friday, December 13. Since April 2024, there have been a total of 61 reported human cases of H5 bird flu reported in the United States.
While an investigation into the source of the infection in Louisiana is ongoing, the CDC 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.
A sporadic case of severe H5N1 bird flu illness in a person is not unexpected; avian influenza A(H5N1) virus infection has previously been associated with severe human illness in other countries during 2024 and prior years, including illness resulting in death. Recently, the UK purchased millions of H5 influenza vaccine to prepare in case of a possible H5 influenza pandemic. But, for now, no person-to-person spread of H5 bird flu has been detected. The Louisiana case does not change CDC’s overall assessment of the immediate risk to the public’s health from H5N1 bird flu, which remains low.
This case underscores that in addition to affected commercial poultry and dairy operations, wild birds and backyard flocks also can be a source of exposure. People exposed to infected animals, either through work or recreationally, are at higher risk of infection and should follow CDC’s recommended precautions when around animals that are infected or potentially infected with H5N1 avian influenza virus. The best way to prevent H5 bird flu is to avoid exposure whenever possible. Infected birds shed avian influenza A viruses in their saliva, mucous, and feces. Other infected animals may shed avian influenza A viruses in respiratory secretions and other bodily fluids (e.g., in unpasteurized cow milk or ‘raw milk’).
As a general precaution, whenever possible, people should avoid contact with sick or dead animals, in particular wild birds, and poultry. For individuals with direct/close contact with wild birds or sick or dead poultry or other animals, wear recommended personal protective equipment (PPE). Wild birds can be infected with avian influenza A viruses even if they don’t look sick. Do not touch surfaces or materials (e.g., animal litter or bedding material) contaminated with saliva, mucous, or animal feces from wild or domestic birds or other animals with confirmed or suspected avian influenza A virus infection.
For more information on H5 bird flu in the U.S. and CDC’s response, including regularly updated case counts, visit the H5 Bird Flu: Current Situation page.
