The United States on Wednesday reported its first serious human case of avian influenza, with a Louisiana resident hospitalized in critical condition after suspected contact with an infected backyard flock.
California, the most populous state, declared a state of emergency over the H5N1 virus after it spread more widely on dairy farms and infected dozens of farm workers this year.
Federal and state authorities have been unable to control the country's outbreak, which first infected dairy cows in 2024, as some farmers resist testing and containment measures.
The Louisiana patient's severe respiratory illness points to an increased public health risk from the virus, which previously caused red eyes and conjunctivitis in infected dairy workers.
The U.S. Centers for Disease Control and Prevention said bird flu remains a low risk to the general public.
The CDC has confirmed 61 human infections nationwide since April, most of them among dairy farm workers who infected cows with the virus.
A worker who slaughters infected poultry also tested positive.
The Louisiana patient has severe respiratory illness, the Louisiana Department of Health said in a statement.
Police say the person has underlying health conditions and is over 65 years old, putting him at high risk.
Demetre Daskalakis, director of the CDC's National Center for Immunization and Respiratory Diseases, said in a call with reporters that this case is the first involving non-commercial backyard poultry.
The CDC notes that sporadic severe cases of H5N1 avian influenza infection are not unexpected and that such cases, including deaths, have occurred in other countries in 2024 and even earlier. He said that
“The mild cases identified in the United States primarily reflect the fact that many people are infected from dairy cows, which is very different from infection from infected birds,” said Johns Hopkins University Research Center Sr. said researcher Amesh Adalja. health safety.
“If you look at the genotype of this patient in Louisiana, it wasn't a cattle lineage. It was a wild bird lineage.”
According to the CDC, partial viral genomic data from infected patients indicates that the virus belongs to the D1.1 genotype, recently detected in wild birds and poultry in the United States, and in recent human infections in British Columbia, Canada, and Washington state. However, it was detected.
The genotype of the virus is different from the B3.13 genotype detected in dairy cattle, human cases in several states, and some domestic poultry outbreaks, the CDC said.
Bird flu has infected more than 860 dairy herds in 16 states since March and killed 123 million poultry since the 2022 outbreak began.
In California, the country's largest milk-producing state, 649 cows, or about 60% of the herd, have tested positive since late August, according to U.S. data.
California Governor Gavin Newsom declared a state of emergency on Dec. 12 after positive tests at four Southern California dairy farms “necessitated a shift from local containment to statewide surveillance and response.” mentioned in.
Previous cases were concentrated in the Central Valley in the central part of the state.
Newsom said the declaration is aimed at streamlining and speeding California's response by increasing flexibility in staffing, contracts and other rules.
The U.S. Department of Agriculture announced that it has enrolled 13 states, representing nearly half of the nation's milk supply, into its newly launched National Milk Avian Influenza Mass Testing Program.
