The first U.S. case of highly pathogenic avian influenza of the year apparently was limited to a turkey flock in southwestern Indiana, but authorities ordered the extermination of 401,163 turkeys and egg-laying hens as a precaution. Investigators recorded more than 220 negative test results after an initial flurry at the start of the Martin Luther King weekend. The USDA and state officials boosted their bird flu detection and response plans following last year’s epidemic that led to the loss of 50 million fowl, mostly turkeys and laying hens — the worst U.S. loss ever to the disease.
“It appears that there was a low pathogenic virus circulating in the poultry population in this area and that virus likely mutated into a highly pathogenic virus in one flock,” said USDA chief veterinarian John Clifford. Highly pathogenic avian influenza, meaning a flu virus with high mortality rate, was confirmed in a commercial turkey flock of 62,213 birds in DuBois County. Nine other cases of avian influenza, also in DuBois County, were confirmed, with the USDA saying eight of those cases were low pathogenic flu. Additional tests were being run on the ninth flock.
All the same, the 10 flocks totaling 245,163 turkeys were marked for destruction along with 156,000 hens on a nearby farm. “These chickens do not have influenza,” said the Indiana Board of Animal Health. “The laying facility is located very close to an infected barn, putting the birds at high risk of contracting the disease.”
“Extreme cold,” which caused some water supplies to freeze, hampered the work of killing the flocks, said the Indiana board.
The USDA said the highly pathogenic virus in Indiana was H7N8, different from the H5 virus responsible for last year’s epidemic. Low pathogenic H7 viruses have been known to mutate to high pathogenic viruses in the past, it said. No human cases of H7N8 flu virus have been reported.
Depopulation, as theUSDA and the industry term the process, is the primary method of preventing bird flu from spreading. Highly pathogenic avian influenza can kill a flock in two days. The usual response to the discovery of bird flu is to quarantine the infected farm and restrict movement of poultry on nearby operations while checking those flocks for disease.
Indiana officials said they visited more than 900 residences in a 10-kilometer (six-mile) radius of the first infected farm to identify backyard flocks of domestic fowl for monitoring and testing. Some 27 small flocks have been located.
The 2015 bird flu epidemic barely touched Indiana. The Hoosier state reported one case, a backyard “hobby” flock of 77 birds in Whitley County, just west of Fort Wayne in the northeastern corner of the state. The epidemic peaked in late winter and spring. Iowa, the No. 1 egg state, and Minnesota, tops in turkeys, had the largest losses.
Some 69 cases of highly pathogenic avian influenza have been reported in France, said the website The Poultry Site.