What you need to know about bird flu and how to protect yourself

Concerns about bird flu are growing among health officials weeks after the first person in the U.S. died from the virus, and as cases of bird flu grow among animals and humans.

Minnesota has no cases of bird flu infection in humans, but does have active infections among poultry and dairy cows. Here are answers to frequently asked questions about bird flu.

The H5N1 virus, known as avian flu or bird flu, is a virus carried by migratory and aquatic birds like ducks and geese. Bird flu has been circulating since the 1990s after being detected in Southeast Asia.

Bird flu spreads when birds like poultry come in contact with wild birds carrying the virus, typically in bodies of water like a pond. Wild birds shed the virus in their saliva, mucus and droppings, which can get on farm equipment and infect domesticated chickens or turkeys, as well as other farm animals.

Stacy Holzbauer, the public health veterinarian with the Minnesota Department of Health, said the first case of poultry in the U.S. contracting this strain of the H5N1 virus was reported last year. The virus has since infected several other species, including domestic cats and aquatic mammals.

Since 2022, more than 200 mammal species have contracted the virus, according to the Centers for Disease Control and Prevention (CDC).

The first reported case of bird flu spreading to dairy cows in the U.S. was reported in March 2024. More than 900 herds in at least 16 states, including Minnesota, were infected. Scientists have found that infected cows shed the virus in their milk, leading to bird flu infections in humans and other animals, such as cats, that consumed raw, infected milk. The virus can spread through contaminated farm equipment.

A concern, Holzbauer said, is that if a person contracts seasonal influenza and bird flu at the same time, the two viruses could mingle and mutate, creating a new, more contagious and drug-resistant strain of flu.

Most humans and other mammals that contract the virus are infected by consuming raw milk or infected poultry, or by coming into contact with the saliva, mucus or feces of infected domesticated animals like chickens, turkeys and dairy cows.

Human-to-human spread, as well as general mammal-to-mammal spread, has not yet been reported.

The people at highest risk are farmworkers who come in close contact with chickens, turkey or cattle, as well as workers at poultry processing plants involved in culling birds. The public’s risk of contracting bird flu remains low, said Jeff Bender, a professor in the University of Minnesota’s School of Public Health.

“If you’re basically somebody that has a backyard flock and your chickens die, and you are cleaning up after them, you might be at risk,” he said. “Or if you’re working on a dairy that has evidence of avian influenza, then you potentially could be at risk, and so there’s extra precautions that are necessary.”

Since 2022, 67 people have been infected in the U.S., and of those, about 40 were dairy workers. The most common symptom in humans with bird flu is conjunctivitis, or pink eye, although many have also displayed mild flu-like symptoms like sore throat, fever, runny nose and a cough, among others.

There is currently no vaccine for bird flu, but the U.S. Department of Health and Human Services recently announced $590 million in funding for Moderna to expedite the development of an mRNA vaccine that would target the H5N1 strain.

Bender suggested that people who come in contact with animals take precautionary measures such as limiting contact between wild birds known to carry the virus and domesticated birds. For people with backyard chickens, that could mean adding extra netting around enclosures and avoiding bodies of water like ponds and streams, where ducks and chickens can mingle.

For larger farms, he recommends communication with animal health officials or veterinarians, providing protective equipment and clothing for workers, and limiting contact with sick birds or cows. Bender also recommends washing hands with soap for at least 20 seconds and getting the seasonal flu shot.

Although bird baths and feeders typically cater to songbirds and the risk of infection remains low for humans, they may attract wild birds that can carry the virus.

The CDC recommends avoiding contact with wild birds like ducks and geese, and observing them from a distance. The agency also recommends avoiding touching any surface that could be contaminated with the saliva, mucus or feces of wild birds.

Rosa Perez, an infectious disease farmworker liaison with the health department, and her team have been traveling the state in recent months to share information about the virus and to administer free flu shots for farmworkers and their families.

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This story comes to you from Sahan Journal, a nonprofit newsroom dedicated to covering Minnesota’s immigrants and communities of color. Sign up for a free newsletter to receive Sahan’s stories in your inbox.