After a relatively tame period for most of 2024, an uptick in highly pathogenic avian influenza is being reported among Utah’s wild birds, the state’s Division of Wildlife Resources said.
Migrating birds are often how infection spreads, according to a spokesperson from the Utah Department of Agriculture and Food.
According to DWR, the current outbreak started in 2022, and cases have been confirmed in 16 counties.
The flu virus has been found in tests of 122 wild birds, a mountain lion, some skunks and three red foxes. Since November, cases have been seen in wild birds in Box Elder, Cache, Carbon, Davis, Emery, Millard, Salt Lake, San Juan, Tooele and Weber counties.
DWR said the virus primarily affects wild birds, including shorebirds and scavengers, as well as raptors and waterfowl. Songbirds normally aren’t affected.
According to DWR, biologists have confirmed an estimated 15,000-20,000 eared grebes have died near the Great Salt Lake, mainly due to the disease. John Luft, the Great Salt Lake’s ecosystem program manager, said it’s unlikely that number will have a meaningful effect on the population.
“Roughly 4 million eared grebes migrate through the Great Salt Lake each year,” he said. “The salinity of the Great Salt Lake almost ‘pickles’ the carcasses, so they don’t decompose or get scavenged like they would in a freshwater environment. The birds will likely continue to wash ashore in the coming months.”
According to DWR veterinarian Ginger Stout, the department “saw a lull” in cases among wild birds between January 2024 and November 2024. Since then, Stout said “we have seen another uptick in new cases across Utah.”
Effects on domestic birds
According to data from the Utah Department of Agriculture and Food, a large outbreak of avian flu was found in October 2024, when 1.8 million egg layers in Cache County were affected. Since then, there have been smaller cases of infections in several counties, though none that reportedly reached even 60,000 birds.
In Salt Lake County, 253 “backyard poultry” birds were listed as affected on Nov. 19.
Bailee Woolstenhulme, the food and agricultural department’s public information officer, said there are currently no known livestock cases in Utah, but that doesn’t mean the virus’ effects aren’t showing up in consumers’ wallets.
She said current high prices for eggs and shortages can be attributed to the 1.8 million affected birds in Cache Valley last year, as well as to ongoing cases nationwide.
(Centers for Disease Control) A transmission electron microscope image of an avian flu strain, seen in gold, grown in canine kidney tissue epithelial cells, seen in green.
In the coming months, Woolstenhulme said she’s not sure if domestic animals will stay free of avian influenza.
“We tend to see more avian influenza cases in the spring and the fall months,” Woolstenhulme said. “That’s because migratory birds are the main carriers of this disease, and so they bring them through when they’re migrating through the state, and that’s the same for the whole country.”
People worried about their own backyard poultry can take steps to protect their livestock — like keeping them in a shelter, preventing contact with wild birds, keeping wild birds away from their food and water and changing clothes and wearing shoes to their coop they don’t wear anywhere else.
Those measures, Woolstenhulme said, can prevent people from stepping in infected bird poop and bringing the virus to their own birds.
Risks for mammals and humans
Along with birds, Utah Department of Health and Human Services epidemiologist Pamela Gomez said there have been infections in about 13 dairy cattle farms in Utah, but no humans have been infected.
“For the general public, I would say that the risk is low of contracting avian influenza,” Gomez said.
For people working with animals like wild birds, dairy cows or poultry, though, the risk could be higher. Gomez advised people who work with animals should avoid direct contact with sick animals. When people do handle or work with animals that have become infected with avian influenza, she advised them to wear protective equipment.
Also, she said, everyone should avoid contact with dead or sick birds or animals in the wild, and report possible cases.
Gomez also said people who haven’t received their flu vaccines could do so to “reduce the chances of getting co-infected with flu and avian flu.”
Since the start of 2024 across the United States, she said 68 people have been infected. Only one person died, and Gomez said that person was over 65 and had underlying medical conditions.
“So far, we have seen that most people that contract avian influenza don’t develop a very severe illness,” Gomez said. “We do want to make sure that we try to avoid humans getting infected with it, because of the possibility that it could mutate and turn into something a little more severe.”
If a person is infected, she said a common symptom is pink eye. People can also develop coughs, runny noses, chills, fevers, headaches, body aches or sneezing.
If someone is concerned they might be infected, Gomez advised them to call the state or their local health department.
