The New York State Department of Environmental Conservation (DEC) has confirmed that Highly Pathogenic Avian Influenza (HPAI) virus has been found in multiple wild bird species in several areas of New York State.
No known HPAI human infections are documented in the U.S., and according to the U.S. Centers for Disease Control and Prevention, these recent cases of HPAI do not present an immediate public health concern for most people. However, people in contact with known infected or possibly infected birds should take precautions to protect against infection and avian researchers are concerned that bird baths and bird feeders can help spread the virus and are asking that they be taken down for a few months.
Avian influenza (AI) is caused by an influenza virus carried by free-flying wild birds, especially ducks, geese, gulls, and shorebirds, but also songbirds. Generally, influenza viruses can infect some wildlife species without causing signs of disease, but new strains can emerge that cause illness with high mortality in both wild birds and domestic poultry. These strains are designated as highly pathogenic, and in wild birds are often cyclical and tied to migration when birds are concentrated in large numbers. As birds spread out on the landscape during the nesting season, disease transmission is expected to decrease.
According to the U.S. Department of Agricultural (USDA), some 31 million birds have been infected so far in commercial and backyard flocks in 29 states.
DEC says it is working cooperatively with the New York State Department of Agriculture and Markets (AGM) and the USDA’s Animal and Plant Health Inspection Service, the agencies leading the joint HPAI incident response, as well as the State Department of Health and Cornell University.
This recently detected HPAI strain likely came from Europe, where it has been circulating since 2020. Since late November 2021, the HPAI H5N1 Eurasian strain began being detected across North America. This outbreak expanded rapidly in mid-March 2022 in North America and HPAI has been detected in many other states, including those that share a border with New York. In February 2022, the first case of HPAI in New York was found in Suffolk County in a domestic flock. Since that time, AGM has detected HPAI in domestic poultry flocks, gamebird breeder facilities, and shooting preserves.
To date in New York, HPAI has been found in captive chickens, pheasants, and ducks in Dutchess, Ulster, Monroe, and Fulton counties. HPAI was detected in free-ranging wild birds in Cayuga, Clinton, Montgomery, Monroe, Onondaga, Seneca, Suffolk, Nassau, Livingston, and Wayne counties.
Wild birds confirmed as infected include snow geese, Canada geese, tundra swan, mute swan, sanderling, mallard duck, redhead duck, ring-necked duck, wood duck, hooded merganser, great blue heron, bald eagles, great horned owls, snowy owl, cooper’s hawk, red-tailed hawk, fish crow, and turkey vulture. Many species of waterfowl, including shorebirds, gulls, raptors, herons and cranes, are also vulnerable.
According to DEC small songbirds have not been adversely affected in New York or other states, but some bird experts are concerned that songbirds gathering at bird feeders and bird baths can spread the virus to more vulnerable birds. It has also infected domestic parrots and according to news reports has killed several. Dr. Victoria Hall with the Raptor Center at the University of Minnesota, said this is an “unprecedented outbreak” about which little is known with regards to songbirds.
“Unfortunately, we have a lot of gaps in knowledge about the role of songbirds in HPAI outbreaks. We have some data from previous outbreaks around the world, but this outbreak is very different. The 2022 outbreak is unique because of the very high levels of transmission of the currently circulating H5N1 virus strain in wildlife. With minimal viral surveillance being done with songbirds, it is hard to measure the risk of transmission from songbirds to other birds,” she said.
“Because the science is unclear on the role of songbirds in this current H5N1 outbreak, one consideration is to not encourage birds to gather together at places such as bird feeders or bird baths. These are places where things like viruses could easily be exchanged between individuals,” Hall said
While the risk of a person becoming infected is low for most people, individuals can protect themselves by only harvesting game that appears to be healthy and properly cooking any game meat being eaten to an internal temperature of 165° F, which kills the virus. If handling wild birds, particularly waterfowl, gulls, and raptors, individuals should follow precautions such as using personal protective equipment like masks, gloves, and eye protection, and washing hands thoroughly.
To assist DEC’s efforts to track HPAI in wildlife and provide an early warning to the State Department of Agriculture and Markets and local poultry or gamebird operations, please report any suspicious deaths to your local DEC regional office.
More information on HPAI may be found at CDC Avian Influenza; New York State Wildlife Health Program Field Biosafety Prototcol; USDA Avian Influenza Updates 2022; USGS HPAI Distribution 2021/2022; and USDA Guidance for Captive Wild Birds.
Illustration of Distribution of Highly Pathogenic Avian Influenza H5 and H5N1 in North America, 2021/2022.