A patient in Louisiana has been hospitalized with a severe case of avian influenza A (H5N1) virus, it is the first Louisiana bird flu case marking the first instance of severe illness associated with the virus in the United States. The case, confirmed by the Centers for Disease Control and Prevention (CDC) on December 13, is part of the 61 reported human cases of H5 bird flu in the U.S. since April 2024.
Louisiana Bird Flu Case Details of the Virus Strain
Preliminary genome analysis of the H5N1 virus infecting the Louisiana patient revealed it belongs to the D1.1 genotype. This genotype has also been detected in recent cases in wild birds, poultry in the U.S., and human cases in British Columbia, Canada, and Washington state. This strain differs from the B3.13 genotype, which has been linked to outbreaks in dairy cows, sporadic human cases, and certain poultry incidents across the United States.
Further genomic sequencing and efforts to isolate the virus from clinical samples are currently being conducted by the CDC to understand more about the strain and its characteristics.
Source of Infection
Investigations into the source of the Louisiana Bird Flu Case suggest the patient was exposed to sick and dead birds in backyard flocks, making this the first case of H5N1 in the U.S. directly linked to backyard poultry. Such sporadic cases of severe H5N1 infection in humans are not unexpected, as the virus has been associated with severe illness and fatalities in other countries during 2024 and previous years.
No evidence of person-to-person transmission of the virus has been detected. The CDC emphasized that this case does not alter the overall assessment of the risk to public health, which remains low.
Risk and Precautions
This case highlights that backyard flocks, in addition to wild birds and commercial poultry, can serve as sources of exposure to H5N1 bird flu. Individuals involved in activities such as poultry farming, hunting, or bird watching are at a higher risk and are encouraged to take precautionary measures to prevent infection.
To reduce the risk of exposure, the CDC recommends avoiding direct contact with sick or dead animals, particularly birds. Infected birds can shed the virus through saliva, mucus, and feces, while other animals can spread the virus through respiratory secretions and bodily fluids, such as unpasteurized milk.
Individuals working with animals that are infected or potentially infected with H5N1 are advised to wear personal protective equipment (PPE) and follow strict hygiene protocols. It is also important to avoid touching contaminated surfaces such as animal litter or bedding material.
Preventive Measures
The best way to prevent H5N1 bird flu is to limit exposure to infected animals. People should avoid contact with wild birds or poultry that appear sick or have died. Even if wild birds do not exhibit symptoms, they can still carry and spread the virus.
For those who handle poultry, game birds, or other animals, using protective equipment such as gloves and masks is crucial. Proper disposal of animal waste and thorough cleaning of equipment and clothing after exposure to animals are also recommended.
The Louisiana case serves as a reminder that bird flu remains a concern for public health, especially for individuals in high-risk occupations or recreational activities involving animals. While the overall risk to the general population remains low, taking preventive measures is essential to minimize potential exposure to this virus.
