A virus responsible for killing a large portion of the nation’s pig herd is accelerating, experts said Friday.

The porcine epidemic diarrhea virus, known as PEDV, is a highly contagious corona virus that causes diarrhea, nausea and death in swine and is spread through ingesting contaminated manure,said Tom Burkgren, veterinarian and executive director of the American Association of Swine Veterinarians.

While the association does not know how the virus is carried from farm to farm, it does know it can be transmitted through exposed clothing and equipment.

“It can be transmitted from a shovel, boots, clothes, trucks, trailers and perhaps rodents or birds,” Burkgren said. “Anything that comes in contact with manure can be a transmission route.”

Although it can be spread through clothing, the virus does not affect humans - only pigs.

“There’s no concern about human or food safety at all with this virus,” Burkgren added.

The fast-spreading virus,first diagnosed in U.S.-raised swine in May, has had a major effect on pork producers since its introduction and is attributed to more than 1.4 million pig deaths nationally from September-December alone, according to the U.S. Agriculture Department’s quarterly hogs and pigs report that was issued Friday. So far, there are no reports of the virus in Arkansas-raised pigs.

The U.S. inventory of all hogs and pigs on Dec. 1 was 65.9 million head, down 1 percent from Dec. 1, 2012, and down 2 percent from Sept. 1, the USDA report said.

“We’re not even looking from when the disease started in April or May,” said Altin Kalo, chief economist with Steiner Consulting Group.

“In diagnostic lab cases, we have seen more positive cases in December,” Burkgren said. “The virus likes cooler weather and is easier transmitted in lower temperatures.”

While there are no true impact numbers, Kalo is concerned about the impact the virus will have on the market.

Among the 2,700 independent hog farmers that Tyson Foods Inc. buys from, there has been an increase in the virus since late October, specifically in parts of the Midwest, said Worth Sparkman, public relations manager for Tyson.

To prevent transmission, Sparkman said his company is mindful of biosecurity on farms.

“We’re also talking with pork industry officials about other measures meat processors and those transporting hogs can take [to] help prevent the spread of the disease(e.g. cleaning, disinfecting, reduced foot traffic from truckers),” Sparkman wrote in an email.

The virus is common in Europe where it was first identified in 1971. The strain that entered the U.S. is virtually identical to a strain in China that was reported in 2012, said Liz Wagstrom, chief veterinarian for the National Pork Producers Council.

“The question is how it got from China and how long it had been in China previous to that,” she said.

Business, Pages 31 on 12/28/2013