A patient in Louisiana has died of bird flu. Health authorities considered the case to be the first severe H5N1 infection in a U.S. resident.
The U.S. has recorded its first human death from bird flu, a grim milestone that comes as at least 67 cases have been recorded in the country.
The patient, who was over 65 and had underlying medical conditions, was hospitalized in Louisiana in December; the case was considered the country’s first severe human H5N1 infection.
The Louisiana Department of Health said the patient had been exposed to a combination of a backyard flock and wild birds.
“The Department expresses its deepest condolences to the patient’s family and friends as they mourn the loss of their loved one,” it said in a statement. “Due to patient confidentiality and respect for the family, this will be the final update about the patient.”
All but one of the human bird flu infections confirmed so far in the U.S. were diagnosed in the last 10 months, according to the Centers for Disease Control and Prevention. Most cases have been relatively mild, with symptoms including pinkeye, coughs or sneezes.
The majority of the patients became sick after exposure to infected cattle or poultry. The Louisiana patient was the first case linked to exposure to a backyard flock.
Just two cases have involved patients who did not have known exposure to animals. One was a person in Missouri who was hospitalized with bird flu in September but recovered after being treated with antiviral medications. The other was a child in California who experienced mild symptoms in November.
The CDC maintains that the immediate risk to public health is low. Public health officials have not found any evidence that the virus has spread person-to-person, which would mark a dire step in bird flu’s evolution.
“While tragic, a death from H5N1 bird flu in the United States is not unexpected because of the known potential for infection with these viruses to cause severe illness and death,” the agency said in a statement on Monday.
“There are no concerning virologic changes actively spreading in wild birds, poultry, or cows that would raise the risk to human health,” the statement added.
However, samples of the virus collected from the Louisiana patient showed signs of mutations that could make it more transmissible to humans, according to the agency.
The strain of bird flu behind the ongoing outbreak began spreading globally among wild birds and poultry in 2020. Since it took root in the U.S. in 2022, more than 130 million birds have been infected or culled. The virus has also spread to dairy cows and other mammals. More than 900 bird flu cases have been detected in cattle since March.
Rising transmission among animals increases the odds that humans could be exposed and that the virus could mutate in ways that could lead to a pandemic. Bird flu appears to spread efficiently on dairy farms, likely because cows shed the virus through their mammary glands, then infect other animals through their raw milk. The virus has also turned up in wastewater in several states, including in sites without dairy or poultry facilities.
For people concerned about bird flu risk, the CDC advises against drinking unpasteurized raw milk and suggests avoiding contact with sick or dead animals. Workers on poultry or dairy farms affected by H5N1 should wear personal protective equipment and monitor for symptoms.
The federal response to bird flu ramped up a month ago, when the U.S. Department of Agriculture ordered testing of the national milk supply, starting in six states. The Biden administration also set aside $306 million last week for additional surveillance, laboratory testing and medical research for bird flu.
But some experts have criticized the U.S.’s response for being too slow or limited.
“The Biden administration has been mishandling the outbreak in cattle for months, increasing the possibility of a dangerous, wider spread,” two former Food and Drug Administration officials wrote in an editorial in The Washington Post on Friday.
