First bird flu death in US reported in Louisiana

A patient in Louisiana who had been hospitalized with severe bird flu has died, the first such death in the United States, state health officials reported Monday.

The patient was older than 65 and had underlying medical conditions, officials said. The individual was infected with the bird flu virus, H5N1, after being exposed to a backyard flock and wild birds.

There is no sign of the virus spreading from person to person anywhere in the state, and Louisiana officials have not identified any other cases in the state. Pasteurized dairy products remain safe to consume.

“I still think the risk remains low,” said Dr. Diego Diel, a virologist at Cornell University.

“However, it is important that people remain vigilant and avoid contact with sick animals, sick poultry, sick dairy cattle and also avoid contact with wild birds,” he added.

The news comes on the heels of a report that the patient had carried mutations that could help the virus infect humans more easily.

The Centers for Disease Control and Prevention said late last month that the mutations were not present in virus samples taken from the backyard herd, suggesting that they developed in the patient as the disease progressed.

One of the mutations was also present in virus taken from a 13-year-old Canadian girl who was hospitalized and required respiratory support. She has since recovered.

Both patients carried a version of the virus that circulates in wild birds, different from the one that caused the outbreak in dairy cattle.

Although these are isolated cases, the two together point to the potential for the virus to mutate into dangerous new forms, experts have said.

The news “should remind us that H5N1 influenza has been and continues to be a dangerous virus,” said Dr. James Lawler, director of the University of Nebraska’s Global Center for Health Security.

“The more widely the virus circulates, particularly infections in humans and other mammals, the greater the risk of the virus acquiring mutations that adapt the virus to human disease and transmission,” he said. “This puts us all at risk.”

This risk is especially heightened as the nation faces a severe flu season.

An individual simultaneously infected with both avian and seasonal influenza viruses may provide H5N1 with ample opportunity to acquire the mutations it needs to spread efficiently among humans.

H5N1 has been circulating in wild birds for several years and in dairy cattle for about a year. The outbreak has shown no signs of abating more than 900 crews in 16 states. The virus has also spread from dairy farms to poultry farms and remains widespread in wild birds.

In December, California, hardest hit by the cattle outbreak, declared a public health emergency.

In any case 66 people have been infected of the virus in the United States this year, according to the CDC Almost all of the cases have been in people who worked on farms with infected cows or poultry.

Most people have had mild symptoms, often conjunctivitis, or pink eye, and respiratory symptoms. Globally, there have been about 500 deaths reported in the past 20 years, most of them in Southeast Asia.

The Louisiana patient was reported to have been hospitalized last month. But state officials have declined to release further details, citing patient confidentiality.

Before last year, only one human H5N1 infection — in a poultry worker in Colorado in 2022 — had been reported in the United States.

Experts have warned against drinking raw milk, which may contain high levels of the virus. No human cases have yet been linked to raw milk, but cats in several states have died after drinking virus-laden milk.