The highly pathogenic H5N8 avian influenza virus has been found on a California turkey farm, marking its first incursion into US commercial poultry after several recent appearances in wild birds and at least one backyard poultry flock in western states.
The virus was found in turkeys from a ranch in Stanislaus County in California's Central Valley, the US Department of Agriculture (USDA) announced Jan 24. "This is the first finding of HPAI [highly pathogenic avian influenza] in commercial poultry during the ongoing disease incident in the Pacific Flyway," the USDA's Animal and Plant Health Inspection Service (APHIS) said.
The agency added that no human cases have been reported anywhere to date and there is no threat to public health.
Virus detected via surveillance
The turkey farm is a Foster Farms facility. In a statement, the company said it detected the virus through its ongoing avian flu surveillance, adding that it has stepped up its poultry biosecurity measures in response to recent discoveries of H5N8 and H5N2 viruses along the Pacific Flyway.
APHIS said the California Department of Food and Agriculture (CDFA) has quarantined the ranch and that federal and state officials would humanely destroy the remaining turkeys there to keep the virus from spreading further.
The USDA said the turkey flock had increased mortality, which prompted testing by the California Animal Health & Food Safety Laboratory System (CAHFS). The H5N8 finding was later confirmed by APHIS's National Veterinary Services Laboratories in Ames, Iowa.
The USDA did not say how many turkeys the ranch housed or how many were sick or died. But Bill Mattos, president of the Modesto-based California Poultry Federation, estimated that the incident could affect up to 200,000 birds in the area, according to a Jan 24 story in the Modesto Bee, a newspaper in Stanislaus County.
The National turkey Federation, in a brief statement acknowledging the finding, stressed that the virus does not pose a danger to the public.
The California finding comes after a string of recent H5N8 detections that began Dec 16, when the virus was found in a captive gyrfalcon in northwestern Washington state. The virus was found in a backyard poultry flock in the southwestern Oregon town of Winston on Dec 19.
Next the virus turned up in a gadwall duck in northern California in early January, and on Jan 13 it was reported in an American widgeon duck in north-central Utah's Davis County.
H5N8 was blamed for widespread outbreaks in South Korea in early 2014, and it found its way into commercial poultry in several European countries in November and December. In addition, farms in Taiwan have been battling the virus this month.
H5N1 in Nigeria, H5N2 in Belize
In other developments, Nigerian officials reported that recent avian flu outbreaks on seven poultry farms were caused by the H5N1 virus, according to a report they filed with the World Organization for Animal Health (OIE) on Jan 23.
The report said the virus struck 2,015 of 36,684 susceptible birds, and 2,000 died. At one of the seven sites, the 298 remaining birds were killed to stop the outbreak, but the report did not mention any culling at the other six sites. The farms are in central and north-central Nigeria.
In still other avian flu news, Belize has reported its first detection of a low-pathogenicity H5N2 virus, says a Jan 23 report the government submitted to the OIE.
Officials said the virus was found through routine testing, with infections in 11,572 of 17,400 susceptible birds; none of the infected birds were clinically sick. The outbreak occurred at Spanish Lookout, which was described as a major poultry production area.
The report said planned control measures included quarantine, control of poultry movements, and "modified stamping out."
Jan 24 USDA press release
Jan 24 Foster Farms press release
Jan 24 Modesto Bee story
Jan 24 National Turkey Federation statement
Jan 23 OIE report on Nigerian outbreaks
Jan 23 OIE report on Belize outbreak