Bird flu cases have increased in the U.S. between species since 2022 with 67 confirmed cases in humans in January, according to the CDC.
The CDC said the current health risks for humans and animals are low, but exposures are being carefully monitored. Bird flu symptoms include eye infections and upper respiratory symptoms.
Concerns about bird flu heightened after the U.S.’ first reported human death of the disease was reported on Jan. 6 by the CDC, University of Minnesota professor of epidemiology Shalini Kulasingam said.
Bird flu, a disease that originated in wild birds and domesticated poultry, recently spread to cattle in March 2024, Kulasingam said. Humans have contracted the disease from working with or eating infected dairy cows and poultry.
University professor in the Department of Veterinary Medicine Declan Schroeder said the current bird flu outbreak is abnormal because of how long it has persisted. Normally, an outbreak of bird flu will last a few months, but this one has been around since 2022.
“The key difference is it has gone into dairy cattle and has been in our dairy industry now for at least a year,” Schroeder said. “The other key thing is we are still getting positive outbreaks in the wild bird population. Usually comes and it disappears, but it just, it has persisted.”
Schroeder said the disease has yet to mutate to be able to spread from person to person, but it can spread from cattle or poultry to humans.
“There’s a few people who work on the farms, and they’ve contracted the virus from working on the farms,” Schroeder said. “So there is no evidence for human-to-human transmission.”
Schroeder said the disease likely spread from wild birds to cattle through bird feces ending up in the cows’ food.
While there is no human-to-human transmission at the moment, there are concerns about the virus mutating as more people become infected, Schroeder said.
“At the moment, we are concerned that if it’s circulating, and it’s been around for a long time, that there’s a chance that it might be taken then come to humans and become human transmitted,” Schroeder said.
However, the chances of the disease mutating in humans in the near future are low, Schroeder said.
“We as humans, unless you’re working on a dairy farm, we’re not exposed to it as much, and so the chances of it mutating in us is low,” Schroeder said.
Kulasingam said it is important to be aware of the poultry and dairy products you consume.
“I think the bigger thing is not eating raw eggs, not drinking raw milk and then cooking your meat to a temperature that’s recommended to kill any viruses,” Kulasingam said.
As the virus multiplies in an animal’s body, it can shed into the milk or meat of the animal.
“That’s why you would want to cook it or have it pasteurized so you could then know that you’re not being exposed,” Kulasingam said. “An analogy would be, remember with HIV, where a concern is that mothers who are breastfeeding and infected can infect their children. It’s not unlike that.”
For those working with infected animals, wearing personal protective equipment like masks and gloves is necessary to protect yourself from the virus, Kulasingam said.
