Photo: Getty Images
Highly Pathogenic Avian Influenza (HPAI) has been circulating in wild birds in North America since December 2021 and continues to be detected in waterfowl in Oregon. More detections are expected during this fall and winter as waterfowl migrate through Oregon or spend the winter here.
An increase in cases and mortality, especially among cackling geese, is already being seen at Staats Lake in Keizer, Fernhill Wetlands in Forest Grove and multiple wildlife refuges and locations where geese are congregating in the valley.
The current strain of the virus (H5N1) was first detected in Oregon in May 2022. Unlike previous outbreaks of HPAI in 2005 and 2014-15, this strain of the virus did not disappear by the following spring. The H5N1 strain continues to circulate in wild birds and is also infecting backyard poultry flocks. Waterfowl are the natural host of avian influenzas and increased spread is occurring during waterfowl migrations.
During fall 2022, most mortality in wild waterfowl occurred in cackling and snow geese, however the virus is also commonly detected in wild ducks that had been harvested by hunters.
Although many Low Pathogenic strains of Avian Influenza naturally occur in wild waterfowl, detections of Highly Pathogenic strains in wild birds are less frequent. Typically, HPAI does not cause large-scale mortality in wild waterfowl or other groups of wild birds but often causes severe illness and death in domestic chickens and turkeys.
However, the current H5N1 strain has caused increased mortality for wild waterfowl (especially geese), shorebirds, raptors and scavengers such as vultures. Currently, there have been 7,476 confirmed detections in 136 species of wild birds throughout the U.S. This strain has also been detected in 15 mammalian species including scavenging carnivores such as coyotes, foxes and skunks that have likely fed on infected birds.
Wildlife managers continue to monitor for the disease by testing birds found dead and sampling live birds and birds harvested by hunters for presence of the virus.
What do to if you encounter groups of sick or dead birds
ODFW asks that members of the public report groups of sick or dead wild birds to the Wildlife Health lab at 866-968-2600 or wildlife.health@odfw.oregon.gov. ODFW staff are monitoring and tracking continued mortalities. Samples may be collected in cases of large groups of dead birds or when multiple different species are involved.
Typical symptoms in wild waterfowl include cloudy eyes, head shaking, swimming in circles, and incoordination. However, HPAI can occur in dabbling duck species that show no signs of disease. These are the carrier host species that spread the virus to other birds and wetlands. Infected wild mammals may be found sick, dead or acting neurologically abnormal after consuming an infected bird and should also be reported.
ODFW veterinarians recommend that you do not handle wildlife that is sick or found dead. If it is necessary to dispose of a carcass, use a shovel or wear impermeable gloves, wash hands with soap and water and change clothing before having contact with domestic poultry or pet birds.
According to the U.S. Centers for Disease Control and Prevention, humans appear to be at low risk for infection with the current H5N1 strain. More info can be found at https://www.cdc.gov/flu/avianflu/avian-in-humans.htm
What hunters need to know
Hunters may come in contact with infected waterfowl during the hunting season and should always practice the following safe bird handling and cooking techniques, especially this season due to HPAI:
- Do not harvest birds that are obviously sick or found dead.
- Wear rubber or latex gloves when handling and cleaning game birds.
- Do not eat, drink, smoke or touch your face when handling birds.
- Keep the game bird and its 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 one gallon 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 ensure the inside of the bird has reached at least 165° F.
- Do not feed dogs raw meat, organs or other tissue from harvested waterfowl.
Falconers are advised to avoid hunting waterfowl and other waterbirds during the HPAI outbreak because of the risk it presents to raptors. HPAI is killing raptors that come into contact with infected avian prey or carcasses.
Danger to domestic poultry
This strain of HPAI (H5N1) is also deadly to domestic birds (chickens, turkeys, Guinea fowl). The Oregon Department of Agriculture (ODA) strongly encourages backyard poultry producers to prevent contact between their birds and wild birds. Any sick domestic birds should be reported to the State Veterinarian’s office at 1-800-347-7028 or AHHotline@oda.oregon.gov
ODFW is part of the State of Oregon’s multi-agency response to HPAI, along with the Oregon Department of Agriculture, the Oregon Health Authority and the US Department of Agriculture’s Animal Plant Health Inspection Service (USDA-APHIS).For information on avian influenza in domestic birds, visit ODA’s website: https://www.oregon.gov/oda/programs/animalhealthfeedslivestockid/animaldiseases/pages/avianinfluenza.aspx
Source: Oregon Department of Fish and Wildlife