USDA Confirms Highly Pathogenic Avian Influenza in Wild Birds in Three States
Veterinary officials confirmed highly pathogenic avian influenza, or HPAI, has been confirmed in wild birds in Virginia, as well as in additional wild birds in North Carolina.
These new cases follow two earlier cases of HPAI reported this year in South Carolina and one earlier case in North Carolina.
HPAI in North Carolina
The initial North Carolina case was reported on January 14 in Hyde County. A press release from the North Carolina Department of Agriculture and Consumer Services, issued on January 27, stated that the virus has now been confirmed in 53 hunter-harvested wild waterfowl at three sites in the state – two in Hyde County and one in Bladen County.
The state’s agriculture department also reported these are the first wild birds in the United States to have Eurasian H5 HPAI since 2016. The positive samples were collected by USDA as part of its ongoing surveillance program for early detection of HPAI in collaboration with state wildlife agencies.
“These findings continue to support evidence that high path avian influenza is currently present in the Atlantic Americas migratory flyway,” said State Veterinarian Mike Martin. “Wild birds can carry this virus asymptomatically and potentially spread it to domestic poultry. We strongly encourage all poultry owners to follow strict biosecurity measures for at least the next 30 days, which is the time frame these birds are anticipated to be migrating through the state.”
HPAI in Virginia
HPAI has been detected in wild birds in Henrico County, Virginia.
Michael Wallace, spokesman for the Virginia Department of Agriculture and Consumer Services, said a highly pathogenic H5 Eurasian strain was confirmed in two hunter harvested birds.
Wallace added there were earlier reports that there were five confirmed cases in both Henrico and Surry counties, but in actuality, there were no confirmed cases in Surry County and only two birds tested positive.
Dr. Charlie Broaddus, Virginia’s state veterinarian, informed the Delmarva Chicken Association, or DCA, the birds were hunted on January 8 and were tested for avian influenza as part of routine disease surveillance.
"This detection is not unexpected, and we continue to recommend the practice of the highest practical level of biosecurity," Broaddus wrote in a memo to DCA.
HPAI in South Carolina
USDA's Animal and Plant Health Inspection Service, or APHIS, confirmed Eurasian H5 HPAI in a wild American wigeon in Colleton County, South Carolina Jan. 14.
Eurasian H5 HPAI has not been detected in a wild bird in the United States since 2016. There was a case of HPAI (H7N3) in one commercial meat turkey flock in South Carolina in 2020 due to a North American lineage virus.
The Centers for Disease Control and Prevention considers the risk to the general public from HPAI H5 infections to be low. No human infections with Eurasian H5 viruses have occurred in the United States. As a reminder, the proper handling and cooking of poultry and eggs to an internal temperature of 165 ̊F kills bacteria and viruses, including HPAI.
Anyone involved with poultry production from the small backyard to large commercial producer should review their biosecurity activities to assure the health of their birds. APHIS has materials about biosecurity, including videos, checklists and a toolkit available at https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/avian/defend-the-flock-program/dtf-resources/dtf-resources.
The United States has the strongest AI surveillance program in the world, and USDA is working with its partners to actively look for the disease in commercial poultry operations, live bird markets and in migratory wild bird populations. APHIS Wildlife Services collected the sample from the hunter-harvested American wigeon, and it was initially tested at the Clemson Veterinary Diagnostic Center (a member of the National Animal Health Laboratory Network). The presumptive positive samples were then sent to APHIS’ National Veterinary Services Laboratories for confirmatory testing.
Since wild birds can be infected with these viruses without appearing sick, people should minimize direct contact with wild birds by using gloves. If contact occurs, wash your hands with soap and water, and change clothing before having any contact with healthy domestic poultry and birds. Hunters should dress game birds in the field whenever possible and practice good biosecurity to prevent any potential disease spread. Biosecurity information is available at: https://www.aphis.usda.gov/publications/animal_health/2015/fsc_hpai_hunters.pdf.
In addition to practicing good biosecurity, all bird owners should prevent contact between their birds and wild birds and report sick birds or unusual bird deaths to state/federal officials, either through their state veterinarian or through USDA’s toll-free number at 1-866-536-7593. Additional information on biosecurity for backyard flocks can be found at http://healthybirds.aphis.usda.gov.
Additional background Avian influenza (AI) is caused by an influenza type A virus which can infect poultry (such as chickens, turkeys, pheasants, quail, domestic ducks, geese, and guinea fowl) and is carried by free flying waterfowl such as ducks, geese and shorebirds. AI viruses are classified by a combination of two groups of proteins: hemagglutinin or “H” proteins, of which there are 16 (H1–H16), and neuraminidase or “N” proteins, of which there are 9 (N1–N9). Many different combinations of “H” and “N” proteins are possible. Each combination is considered a different subtype and can be further broken down into different strains which circulate within flyways/geographic regions. AI viruses are further classified by their pathogenicity (low or high)—the ability of a particular virus strain to produce disease in domestic chickens.