US Reports First Case of Severe Bird Flu Infection
The US Centers for Disease Control and Prevention (CDC) has confirmed a severe case of H5N1 bird flu infection in a patient hospitalized in Louisiana, marking the first known instance of a severe human illness linked to the virus in the country. The patient was hospitalized with a severe case of H5N1 infection, which is not unexpected, as sporadic cases of severe H5N1 bird flu illness have been reported in other countries in 2024 and prior years.
Partial viral genome data from the infected patient shows that the virus belongs to the D1.1 genotype, which has been detected in wild birds and poultry in the US and in recent human cases in British Columbia, Canada, and Washington state. This genotype is different from the B3.13 genotype detected in dairy cows, human cases in multiple states, and some poultry outbreaks in the country.
The Louisiana case is the first to be linked to backyard, non-commercial poultry, according to Demetre Daskalakis, director of CDC’s National Center for Immunization and Respiratory Diseases. The virus has infected more than 860 dairy herds in 16 states since March and has killed 123 million poultry since the outbreak began in 2022.
There has been no evidence of dairy herds being reinfected once they have cleared the virus, said U.S. Department of Agriculture Deputy Under Secretary Eric Deeble. The agency has enrolled 13 states in its newly launched national bulk milk bird flu testing plan, representing nearly half of the nation’s milk supply.