Strain of bird flu virus never before reported in people is behind first human case in U.S. in nine months

As of mid-September, 71 human cases of bird flu have been reported in the US as part of the ongoing outbreak, with one death. (Credit: Cynthia Goldsmith/Jackie Katz/CDC/AP via CNN Newsource)

A Washington resident has been hospitalized with bird flu, according to the Washington State Health Department, and they’re infected with a strain of the virus that hasn’t been seen in humans before.

It’s the first reported case of bird flu in a human in the U.S. in nine months, but the U.S. Centers for Disease Control and Prevention says that the risk to the general public from the virus remains low.

The patient, who has been hospitalized with H5N5 avian influenza since early this month, is described as an older resident of Grays Harbor County who has underlying health issues. It isn’t clear exactly how they caught the virus; state and local public health and agriculture officials are investigating, but they suspect that the person may have been exposed through backyard poultry.

The virus spreads through an animal’s saliva, mucus and feces, or through milk from dairy cattle. The general risk of bird flu goes up in the late fall and winter as birds migrate and come into contact with other animals like backyard flocks.

Bird flu has been infecting wild birds around the world for decades, but the latest U.S. outbreak started in January 2022 and has featured more spread among mammals than in past years.

There has been no known human-to-human transmission of the virus in the U.S., but public health leaders in Washington are contacting people who may have been in close contact with the Grays Harbor patient to check for symptoms and offer testing and treatment.

Even though the overall risk to the public is low, Dr. Richard Webby says, the virus still has “pandemic potential.”

“I think it’s clear it’s not an easy leap for this virus to make, to switch from being a duck virus to being a human virus. I think that’s pretty clear, but I certainly wouldn’t put money on the fact that it can’t make that leap,” said Webby, director of the World Health Organization Collaborating Centre for Studies on the Ecology of Influenza in Animals and Birds. “It’s going to take a little bit of the biologic stars aligning for that to happen. We could argue exactly how likely that is, but no one actually knows. Only time will tell us, unfortunately.”

Seventy other human cases of bird flu have been reported in the U.S. as part of the ongoing outbreak, according to the CDC. One person died in January who was also elderly and had underlying conditions.

Although a handful of cases have been severe, most people who have been infected have had mild illness, the CDC said, with symptoms like red eyes and fever.

The majority of those who have caught bird flu work closely with animals. There have been 41 cases in people who work with cattle and 24 cases among poultry workers. Two other cases have had some other animal exposure that the CDC does not list, and in three cases, the exposure was unknown.

The CDC recommends that anyone who works closely with animals wear appropriate protective equipment and use caution around animal feces.

The Washington State Department of Health urges people cleaning up around bird feeders and other areas exposed to bird feces to wear gloves and disinfect the area with a mixture of one part bleach to 10 parts water or a commercial disinfectant like Lysol spray.

Avoid contact with sick or dead wildlife. If disposing of a dead bird, wear a well-fitting face mask and disposable gloves, and use an inside-out plastic bag to pick up the carcass. The health department suggests double-bagging the bird and disposing of it in a sealed trash can so other animals don’t try to eat it. Wash hand thoroughly afterwards.

Avoid consuming uncooked, undercooked or unpasteurized food like raw cheese or raw milk.

The health department also recommends getting a flu shot. Although the regular influenza vaccine can’t protect against bird flu, it reduces the slight chance that someone could get sick with both viruses at once and cause the bird flu virus to mutate into something that would spread easily among humans.