Nearly 74,000 chickens were killed and buried on a farm in southern Tennessee in an effort to stem an outbreak of highly pathogenic avian influenza, said state officials. The first round of samples from flocks on neighboring farms were free of the disease, said state veterinarian Charlie Hatcher, who cautioned, “We’ll be in this thing for a long haul.”
The discovery of “high path” bird flu on a broiler-breeder farm in Lincoln County was the first U.S. case this year. It involved an H7 strain of North American lineage, said Hatcher. Health officials are worried about an H7N9 strain involved in an ongoing outbreak in China that has jumped species to infect and kill humans.
“Although some limited human-to-human spread continues to be identified, no sustained human-to-human (H7N9) transmission has been observed,” said the CDC in a discussion of the disease in China. “Most human infections continue to result in severe respiratory illness and have been associated with poultry exposure.” Tennessee officials emphasized the risk to humans from the virus on the Lincoln County farm was low and the disease was not foodborne.
Wild birds, particularly migratory waterfowl, are believed to spread bird flu. It’s not clear, Hatcher said, how the virus infected the flock. The disease was confirmed in only one of the eight chicken barns on the farm. “Biosecurity was excellent,” he said during a news conference in Nashville.
The farm, under contract to Tyson Foods, produced eggs for hatching into chicks that were destined for slaughter to yield broiler meat. Agriculture officials quarantined at least 30 poultry farms in a 10-mile radius to keep the disease from spreading.
Hatcher said the incubation period for high-path bird flu, which gets its name for its high mortality rate, is a week or so. “Our surveillance period is for at least two weeks on all premises,” he said. Asked how long it would take to be sure the disease was eradicated, he replied, “We’re talking several weeks at least.”
Some 50.4 million chickens and turkeys, including 10 percent of the hens that lay eggs for table consumption, died in the worst-ever U.S. bird flu epidemic from late 2014 through spring 2015. Cases were confirmed on 211 commercial flocks and 21 backyard flocks in 15 states. Dozens of countries banned or restricted import of U.S. chicken meat although the broiler industry was not involved.
In response to the new U.S. case, South Korea, Japan, Taiwan and Hong Kong restricted imports of U.S. poultry, said Reuters.
“We do not currently have any additional cases,” said a USDA spokeswoman. “We are asking for producers and growers to stay on top of their biosecurity. It’s extremely important to remain vigilant with biosecurity practices.”
To watch a video of the Tennessee news conference, click here.