The Louisiana Department of Health said on Monday that a U.S. patient hospitalized with H5N1 bird flu has died, the country’s first death from an outbreak of the virus that has sickened dozens of people and millions of poultry and cattle.
Nearly 70 people in the U.S. have contracted bird flu since April, according to the U.S. Centers for Disease Control and Prevention, most of them livestock workers exposed to sick chickens or dairy cattle.
The patient in Louisiana, the first person in the country to be hospitalized with the virus, contracted bird flu after exposure to a combination of backyard chickens and wild birds, said Louisiana health officials. The patient was hospitalized on Dec. 18, 2024, state health officials said.
Health officials said the patient was over 65 and had underlying medical conditions. The person had been in contact with sick and dead birds in a backyard flock.
State officials previously said the individual was a resident of southwestern Louisiana. No details were provided about when the death occurred.
There is no sign that the virus is spreading from person to person, a key trait that scientists watch for in assessing the pandemic potential of a flu virus.
Mutations similar to those found inside B.C. patient
The U.S. officials also said a genetic analysis had suggested the bird flu virus had mutated while inside the Louisiana patient. The mutations may have increased the virus’s capacity to attach to cells in the upper respiratory tract, a technical summary from the U.S. Centers for Disease Control and Prevention suggests.
Samples from a teenager in British Columbia showed similar mutations, Canadian and U.S. researchers reported last week. They said the 13-year-old girl had been in critical care and no longer needs supplemental oxygen.
A hospitalized 13-year-old B.C. girl believed to be the first person to acquire H5N1 avian flu in Canada is now out of intensive care and breathing on her own. The source of her infection remains unknown, but she is no longer infectious.
Both patients carried a version of the virus found in wild birds rather than what’s behind the outbreak in U.S. dairy cattle.
Previous illnesses in the U.S. have been mild, and most have been detected among farm workers exposed to sick poultry or dairy cows. In two cases — an adult in Missouri and a child in California — health officials have not determined how they caught it.
“While the current public health risk for the general public remains low, people who work with birds, poultry or cows, or have recreational exposure to them, are at higher risk,” the Louisiana department said in a statement.
The CDC did not immediately respond to a request for comment.
Most U.S. bird flu cases in humans reported mild symptoms, including conjunctivitis, or pink eye.
Wake-up call for public health?
“Though H5N1 cases in the U.S. have been uniformly mild, the virus does have the capacity to cause severe disease and death in certain cases,” said Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security in Baltimore. The Louisiana patient was at high risk from influenza given their age and underlying conditions, he said.
The death is not surprising given that bird flu has killed people in other countries, said Gail Hansen, a veterinary and public health consultant.
“I hate to have the death of somebody be a wake-up call,” she said. “But if that’s what it takes, hopefully, that will make people look at bird flu a little more carefully and say this really is a public health issue we need to be looking at more closely.”
