On December 18, 2024, health officials in Louisiana reported a patient hospitalized due to a severe case of avian influenza A(H5N1) — commonly known as bird flu. This incident marks the first severe illness associated with H5N1 in the United States, as confirmed by the Centers for Disease Control and Prevention (CDC) on December 13. Since April 2024, there have been 61 documented human cases of this virus in the U.S.
Preliminary viral genome analysis of the strain involved in the Louisiana case suggests it belongs to the D1.1 genotype, which is linked to other D1.1 strains identified in wild birds and poultry within the U.S., as well as in recent human cases in British Columbia, Canada, and Washington state. This strain contrasts with the B3.13 genotype that has appeared in dairy cows and sporadic human instances across various states. The CDC is currently conducting additional genomic sequencing and isolating the virus from the patient’s clinical specimens for further study.
An ongoing investigation has revealed that the Louisiana patient had direct contact with sick and deceased birds in local backyard flocks, marking the first instance of H5N1 bird flu linked to this source in the U.S. Although cases of severe H5N1 infections in humans are uncommon, they have been recorded in other countries during 2024 and prior years. Thus far, no instances of human-to-human transmission of bird flu have been reported. The CDC continues to assess the immediate health risk to the public from H5N1, which remains categorized as low.
This situation serves as a crucial reminder that both commercial poultry operations and private backyard flocks can pose a risk of exposure to the virus. Individuals who interact with birds, whether for work or recreational purposes, should adhere to the precautionary measures recommended by the CDC, ensuring they protect themselves when engaging with potentially infected animals.
To minimize the risk of H5N1 infection, the CDC advises avoiding contact with sick or deceased birds, along with practicing proper hygiene protocols. Infected birds can spread the virus through their saliva, mucous, and feces. If a person must handle wild birds or sick poultry, wearing recommended personal protective equipment (PPE) is essential. Additionally, individuals should refrain from touching surfaces contaminated with animal waste from birds or animals suspected of having the avian influenza virus.
For ongoing updates and detailed information regarding H5N1 bird flu in the U.S., including current case counts, the public is encouraged to visit the CDC’s dedicated H5 Bird Flu page.
In summary, while this recent case highlights the potential risks associated with avian influenza, it also underscores the importance of vigilance and adherence to safety guidelines among those exposed to birds. The CDC’s proactive response serves as a reassurance, reminding us all of the effectiveness of preventive measures in protecting public health.