Health officials in Louisiana have confirmed a critical case of H5N1 avian influenza, marking the first severe human infection of its kind in the United States. The Centers for Disease Control and Prevention (CDC) indicated that the individual likely contracted the virus through contact with a backyard flock.
“The patient is hospitalized in critical condition with a severe respiratory illness linked to H5N1,” said Emma Herrock, spokesperson for the Louisiana Health Department.
Preliminary investigations suggest that exposure to sick or dead birds on the patient’s property was the likely source of infection, explained Dr. Demetre Daskalakis, director of the National Center for Immunization and Respiratory Diseases.
The Louisiana Department of Health initially flagged the case as a presumptive positive, which was later confirmed through CDC laboratory analysis. Officials are now conducting a thorough investigation, offering antiviral medications and testing to individuals who may have been in close contact with the patient.
The individual, described as being over 65 with pre-existing health conditions, has not been publicly identified. Further details regarding the patient’s symptoms or the flock involved have not been disclosed.
This year, 61 human cases of avian influenza have been reported in the U.S., most of them mild and linked to direct contact with infected poultry or livestock. A probable case in Wisconsin involving exposure to birds at a commercial farm is currently under review by the CDC.
Experts emphasize that human-to-human transmission of H5N1 has not been observed. Infections typically result from direct contact with infected animals, and symptoms often include respiratory distress, conjunctivitis, or flu-like signs.
The strain of the virus identified in Louisiana appears consistent with one circulating in wild birds and poultry in Canada and the Pacific Northwest. Last year, a teenager in British Columbia was hospitalized with a similar strain, though the exact source of that infection was not determined.
H5N1 has been a persistent threat since it began spreading widely among wild birds and poultry in 2022. To date, over 123 million birds in the U.S. have been lost to infection or culling efforts. This year, the virus has also been detected in dairy cattle across multiple states, raising new concerns about its ability to spread among mammals.
Research indicates that infected cows may shed large amounts of the virus through raw milk, suggesting a potential route of transmission within livestock populations. While there is no evidence of human-to-human spread, scientists remain vigilant about the possibility of mutations that could increase transmissibility.
The Louisiana case is being treated as the first severe H5N1 infection in the U.S., distinct from earlier hospitalizations where other health conditions played a larger role.
Separately, Delaware health officials recently reported a suspected case in a person with no known exposure to poultry or livestock. However, CDC testing could not confirm the virus, leaving the case classified as “probable.”
