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USDA Studying Iowa Rodents for Avian Flu

Flickr / J. N. Stuart
Some researchers believe it's possible small mammals and birds are carrying infected material into poultry barns, and thus causing the ongoing avian flu outbreaks.

A team of wildlife biologists from the United States Department of Agriculture will be trapping small mammals and birds in Iowa and testing them for avian influenza over the next couple of weeks. USDA epidemiologists will also be interviewing workers at poultry operations about bio security practices. 

Iowa is the nation's leading poultry producer and so far more a third of the state's hens have been affected by the H5N2 virus. Nationwide the number of affected birds totals to 33 million. Avian influenza presents no food safety concerns.

The Centers for Disease Control and Prevention says there are no confirmed cases of avian flu in mammals, and the USDA still believes migratory birds are responsible for carrying the virus to the Midwest. But the in between steps of how avian flu travels from wild birds into poultry barns is a mystery.

"There's actually evidence in the scientific literature that mice and other small rodents can actually carry the virus. Maybe not as a biological vector, but as a mechanical one," says Dr. Brian McCluskey, the chief epidemiologist for the USDA's Animal and Plant Health Inspection Service.

Credit Urner Barry
Urner Barry chart of egg prices for 2013, 2014 and 2015 over a 12 month period.

McCluskey says a mouse might enter a poultry barn with contaminated material in its fur or on its paws. Once a single bird tests positive for avian flu the entire flock is eradicated so as to prevent the spread of the disease. 

The USDA is also investigating other theories about how the virus continues to inflect flocks, despite heightened bio security measures. Some theories include examining poultry feed, different bio security practices, the movement of vehicles from facility to facility, the distance of a poultry barn from water, and a barn's distance from crop fields.

In the meantime egg and turkey prices have risen slightly, according to New Jersey-based Urner Barry, a commodities analyst firm. Compared to this time last year, the price of a dozen large, white eggs is up roughly 5 cents.

"I think it's too early to tell what the consequences will be price-wise," says Randy Olson, director of the Iowa Poultry Association. "We're an important state, but we're not the only state. There will be some price consequences, but...prices fluctuate." 

Ultimately, a lot rides on how many more hens are lost to the flu. Officials are hopeful the hot summer weather will soon kill the virus.