Fall migration brings an increase in bird flu detections in Oregon

PORTLAND, Ore. (KATU) — With migratory waterfowl returning to the cold seasons, Oregon is the first state to report new increases in bird flu detections during fall migration.

Avian flu and wild bird mortality are seen again in the state, especially with cackling geese flocking to the Willamette Valley. Highly pathogenic avian influenza (HPAI) was first detected in wild birds in North America in December 2021 and was first seen in Oregon in May 2022.

According to Oregon Fish and Wildlife, this specific strain of the virus (H5N1) did not disappear the following spring like the outbreaks before it in 2005 and 2014-15.

The H5N1 strain continues to circulate among wild birds, backyard poultry flocks,dairy herds and other livestock. It was discovered that it is also contagious pigs in Oregon and farm workers in 14 states.

Waterfowl such as geese, ducks and swans are the natural host for bird flu, making it easy for the virus to move throughout North America during their spring and fall migrations. In Oregon, the majority of wild waterfowl mortality occurs in cackling geese, especially young birds.

The virus is also commonly found in wild ducks harvested by hunters.

Many low-pathogenic strains of avian influenza can occur naturally in wild waterfowl, but detection of highly pathogenic strains in wild birds is less common. HPAI does not typically cause large-scale mortality in wild birds, but often causes severe illness in domestic chickens and turkeys.

The H5N1 strain has caused increased mortality in wild waterfowl (especially geese), shorebirds, raptors and vultures. So far, there are 10,400 confirmed cases in 153 species of wild birds across the United States

MORE COVERAGE: 4 farm workers test ‘presumably positive’ for bird flu, first case in WA

This strain has also been detected in at least 20 wild mammals, including three marine mammals, and carnivores such as coyotes, foxes and skunks, which likely ingested infected birds.

HPAI has been confirmed in dairy cattle in three states, California, Utah, and Idaho. Oregon has confirmed HPAI cases in poultry and recently in a pig from a non-commercial farm. Three commercial poultry flocks and 38 backyard flocks have been affected in the state.

There are currently 404 cases of HPAI detected in wild mammals, including red foxes, striped skunks, bottlenose dolphins, raccoons and domestic cats.

The USDA is taking note cats and other scavenging species “are typically hapless for this avian influenza virus, meaning that, with rare exceptions such as transmission among family groups or where they roost together, they are not significantly involved in onward transmission.”

People stay at low risk for infection with the current strain according to the US Center for Disease Control and Prevention. There are currently 46 confirmed cases in humans, according to the CDC.

Oregon had its first human case on Friday, October 16, as confirmed by the Oregon Health Authority.There is limited information about the individual infected. However, the case is in Clackamas County and was reported to be a mild case, making a full recovery.

READ MORE ON OREGON’S FIRST HUMAN CASE: Medical officials confirm Oregon’s first human case of bird flu in Clackamas County

Virologist and professor Dr. Alex Greninger at the University of Washingtonexplained winter and colder seasons increase the transmission of respiratory infections and lead to the emergence of new strains. Bird flu, he said, is not spreading like COVID-19 did in 2020 and that there are effective antiviral drugs such as Tamiflu and Baloxavir.

While not on the same level as COVID-19, the strain’s newness to the United States means officials must closely monitor and protect those most at risk, such as farm workers and hunters.

Typical symptoms to look out for in wild waterfowl include blurry eyes, head shaking, swimming in circles and incoordination. However, HPAI can occur in poodle duck species without showing signs of disease.

Infected mammals may be found sick, dead, or neurologically abnormal after eating an infected bird.

Hunters may come into contact with infected waterfowl during the hunting season and should practice safe bird handling and cooking techniques.

Veterinarians at ODFW recommend that you do not handle sick or dead wildlife. When necessary to handle a carcass, be sure to use a shovel or wear impervious gloves. Wash hands thoroughly and change clothes before coming into contact with domestic poultry or pet birds.

ODFW has issued the following guidelines for hunters handling wild birds:

• Do not harvest or eat birds that are obviously sick or found dead

• Field dress and prepare game birds outdoors or in a well-ventilated area

• Wear rubber or latex gloves and eye protection when handling and cleaning game birds. An N95 respirator or tight-fitting face mask (eg, surgical mask) is an optional additional layer of protection referenced in current CDC guidelines.

• Do not eat, drink, smoke or touch your face when handling birds.

• Keep game birds and their juices away from other foods.

• Thoroughly clean knives and any other equipment or surfaces that touch birds. Use a solution of one-third cup of chlorine bleach per gallons of water.

• Wash your hands with soap and water for at least 20 seconds after handling birds (or with alcohol-based hand products if your hands are not visibly soiled).

• Cook all game meat thoroughly (up to at least 165 F) to kill disease organisms, including bacteria, viruses and parasites. Use a food thermometer to make sure the inside of the bird has reached at least 165 F.

• Do not feed raw meat, organs or other tissue from harvested waterfowl to dogs.

• Falconers are also advised to avoid hunting waterfowl and waterfowl during the current HPAI outbreak to avoid the risk it poses to raptors. The strain continues to sicken and kill raptors that come into contact with infected bird prey or carcasses.

ODFW encourages the public to report groups of sick or dead wild birds to the Wildlife Health Lab at 866-968-2600 or [email protected] and to report death or illness among domestic birds (chickens, turkeys, guinea fowl) ) to ODA at 503-986-4711.

To learn more about protecting backyard herds, read morehere.