Photo: Justin Sullivan / Getty Images News / Getty Images
Photo: Getty Images
With migratory waterfowl back in Oregon for the winter, the state is again seeing an increase in cases of avian flu and mortality in wild birds, especially among cackling geese congregating in the Willamette Valley. Oregon is the first state to report a new spike in detections this fall.
Highly Pathogenic Avian Influenza (HPAI) was first detected in wild birds in North American in December 2021 and in Oregon in May 2022. Unlike previous outbreaks of HPAI in 2005 and 2014-15, this specific strain of the virus (H5N1) did not disappear by the following spring. The H5N1 strain continues to change and circulate in wild birds and is also infecting backyard poultry flocks, dairy herds and other livestock including pigs in Oregon. It has also infected farm workers in 14 states.
Waterfowl are the natural host of avian influenzas and the virus moves throughout North America during spring and fall waterfowl migrations. In Oregon, most mortality in wild waterfowl occurs in cackling geese, especially juvenile birds, however the virus is also commonly detected in wild ducks harvested by hunters.
Although many Low Pathogenic strains of avian flu 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 10,400 confirmed detections in 153 species of wild birds throughout the U.S. This strain has also been detected in at least 20 wild mammalian species including three marine mammals and scavenging carnivores such as coyotes, foxes and skunks that have likely fed on infected birds. HPAI has been confirmed in dairy cattle in 14 states, including California and Idaho. Oregon has confirmed HPAI in poultry and recently in a pig from a noncommercial farm.
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.
Wildlife managers continue to monitor for the virus by testing wild birds found dead and sampling live birds and birds harvested by hunters.
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.
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 or consume birds that are obviously sick or found dead.
• Field dress and prepare gamebirds outdoors or in a well-ventilated area
• Wear rubber or latex gloves and eye protection when handling and cleaning game birds. A N95 respirator or well-fitting facemask (e.g. surgical mask) is an optional extra layer of protection and is referenced in the current CDC guidelines.
• 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 continues to sicken and kill raptors that come into contact with infected avian prey or carcasses.
Danger to domestic poultry
Death or illness among domestic birds (chickens, turkeys, Guinea fowl) should be reported immediately to ODA. Please report by calling 503-986-4711 (Alt phone 1-800-347-7028). For more tips on protecting backyard flocks, please visit ODA online at Avian Influenza or en Español at Avian Influenza-Spanish.
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 U.S. Department of Agriculture's Animal Plant Health Inspection Service (USDA-APHIS). Find more information on avian influenza in domestic birds from ODA
Source: Oregon Department of Fish and Wildlife