A backyard chicken raised to lay eggs. (Photo by Jared Strong/Iowa Capital Dispatch)
A highly contagious avian influenza sickened a backyard flock of chickens and ducks in Pottawattamie County, and the birds were incinerated this week to prevent further spread of the virus, state agriculture officials said Wednesday.
The infection of the flock of fewer than 50 birds was confirmed by an Iowa State University veterinary lab on Tuesday, according to the U.S. Department of Agriculture. It’s the state’s first known case this year.
State officials have been on the lookout for the virus — which is deadly for domestic birds but is unlikely to affect humans — since its detection in wild birds and commercial flocks in other states in recent months.
It was discovered in wild birds in South Carolina in mid January, according to the USDA, and has since been confirmed in hundreds of wild birds along the East Coast and also in backyard and commercial flocks in eight states.
Wild birds often do not show symptoms of infection, and they are likely to have transmitted the virus to the Pottawattamie flock, State Veterinarian Jeff Kaisand said Wednesday.
“We can’t say exactly, but there’s a strong concern that migratory birds would be a potential source of the infection,” he said.
The virus can be devastating for large, commercial flocks, and Iowa is the nation’s leading egg producer. A bird flu outbreak in 2014 and 2015 resulted in the culling of more than 34 million birds on 77 Iowa farms, according to a study commissioned by the Iowa Farm Bureau Federation.
The “2015 outbreak was the largest foreign animal disease outbreak in U.S. history, and a significant percent of that activity was in the state of Iowa,” Secretary of Agriculture Mike Naig said Wednesday.
He declined to speculate about how the state will fare this year but said early detection of the virus and swift action to eliminate infected flocks are key to limiting its spread.
Kaisand said there are no commercial operations within 10 kilometers of the Pottawattamie flock, but he is monitoring three backyard flocks within that surveillance zone, which includes part of Mills County.
The virus was first detected in a commercial flock this year in Indiana on Feb. 8, which affected about 29,000 turkeys. The virus has since been found in four other commercial turkey flocks in that state and in backyard and commercial flocks in Connecticut, Delaware, Kentucky, Maine, Michigan, Virginia and New York. The largest flock affected was 1.2 million commercial birds in Delaware on Feb. 22.
There have been four previous outbreaks of highly pathogenic avian influenza in the United States, in 1924, 1983, 2004 and 2014-2015, according to the USDA.
The most recent of those — which began with the virus’ detection in backyard Oregon poultry in December 2014 — was the worst and resulted in the culling of more than 50 million birds.
The 1983 outbreak was the second deadliest and affected about 17 million poultry in the northeastern United States.
The 2004 outbreak was contained to one flock of chickens in the southern part of the country, and the 1924 outbreak was contained to live bird markets on the East Coast, according to the USDA.
Kaisand said Iowans who have flocks of poultry — whether they are large or small — should limit contact with wild birds and avoid their feces. He said it’s crucial to monitor flocks for symptoms of the flu, such as death, lethargy, abnormal egg production, breathing difficulties and others, and to report potential infections to the Iowa Department of Agriculture and Land Stewardship by calling (515) 281-5305.
“This is a time to go to higher alert,” Naig said. “Hard to predict where this season will go, but the next couple of months will be very important that folks keep that focus on biosecurity.”
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