Avian flu detected in three wild birds in California. How dangerous is the virus?

Three cases of avian flu have been detected in wild birds in Colusa and Glenn counties, the California Department of Fish and Wildlife announced.

The U.S. Fish and Wildlife Service collected the three infected birds — two Canada geese and one American white pelican — during a mortality event at the Sacramento National Wildlife Refuge Complex on July 5. The U.S. Department of Agriculture confirmed the presence of avian influenza H5N1 in the birds on Wednesday.

“These are the first detections of avian influenza H5N1 in wild birds in California,” state wildfire officials said in a Thursday news release. “Although avian influenza viruses naturally circulate among waterbirds, the strain of H5N1 currently in circulation in the U.S. and Canada has been causing illness and death in a higher diversity of wild bird species than during previous avian influenza outbreaks.”

The first cases of this strain of the virus were detected in captive and wild birds along the Atlantic coast of Canada in late 2021, according to the California Department of Fish and Wildlife website. Since January 2022, the strain has been detected in 1,825 wild birds in 42 states and the District of Columbia, as well as 386 domestic poultry and mixed-species flocks in 37 states.

No infections of this strain of the virus have been detected in humans in the United States, and the U.S. Center for Disease Control and prevention considers the risk to the general public to be low. The disease, which is rare in humans and typically caused by direct contact with birds or infected surfaces, can cause symptoms similar to those of human influenza. There is no treatment for the disease.

However, the disease remains highly contagious for domestic poultry. California wildlife officials cautioned against feeding or providing water to wild birds, especially near backyard poultry or captive birds like ducks, geese, pigeons, doves and parrots.

There is potential for the virus to infect other mammals as bird flu viruses evolve.

Last month, Washington state officials announced the first case of avian flu confirmed in a raccoon in North America. Avian flu has previously been detected in red foxes and skunks in North America. Elsewhere in the world, it has infected pigs in Asia, domestic cats in Germany, and a domestic dog in Thailand.

The department also suggested that bird owners avoid allowing wild birds into enclosures with domestic birds or allowing wild and domestic birds to share food or water.

Sacramento Zoo officials said Friday that they will continue taking steps to protect animals as part of its comprehensive disease prevention plan.

“In some cases, birds – like the flamingos and others who live on the zoo’s open-air lake habitat – will be temporarily relocated to safer housing off exhibit,” zoo officials said. “Some of the larger birds – ostrich and emu – are currently remaining in their habitats under the watch of the animal care and veterinary teams but may be moved into shelters.”