All poultry shows at the Ohio State Fair and county fairs across the state have been canceled this year because of the threat of a deadly bird flu virus, the state's agriculture department announced Tuesday.

The virus that has led to the deaths of more than 44 million chickens and turkeys in the Midwest hasn't been found so far in Ohio, but state officials said banning all poultry shows is a needed step to protect Ohio's $2.3 billion poultry industry.

The order applies to poultry auctions, swap meets and all other gatherings of birds for show or sale as well as fairs.

"This was a difficult decision because it means young people can't show their birds at fairs, but it's in the best interest of an industry that literally thousands of Ohio families and businesses depend on and which provides billions of dollars to our state's economy," Ohio Agriculture Director David Daniels said in a statement.

Several other states already have canceled poultry shows at fairs this summer, including Indiana, Pennsylvania, West Virginia and Michigan.

Iowa, the nation's leading egg producer, has lost more than a third of its egg-laying chickens, causing prices to soar.

Scientists believe migratory waterfowl carry and help spread the H5N2 avian influenza virus. Wild ducks and geese don't become sick from it but can spread it through their droppings. It's thought that the virus can get into poultry barns on workers' shoes or clothing, or perhaps on contaminated dust.

Health officials say humans are not at risk of getting this strain of bird flu.

Ohio's state veterinarian, Dr. Tony Forshey, said fairs and other poultry shows have a high risk of unintentionally spreading the virus to other farms.

"Until we can be sure that there has been no transference from the wild bird population migrating through the state, we need to do all we can to minimize the exposure for our domestic birds," he said.

The directors who oversee Ohio's county fairs and the state fair both said they supported the decision.

"Ohio's poultry industry plays a vital role in our state's economy and agricultural development, and we want to do everything we can to preserve the health of Ohio's birds," said Virgil Strickler, general manager of the Ohio State Fair.