PED can be spread by air, say U.S. researchers

Wednesday, September 10, 2014

by SUSAN MANN

Ontario hog famers should maintain their same heightened biosecurity protocols for now even though American researchers have found there’s a possibility porcine epidemic diarrhea virus can be spread by air.

Mike DeGroot, Ontario Pork’s national biosecurity coordinator, says the virus is predominately spread by fecal-oral contact and not by air but under certain conditions airborne transmission is a possibility.

PED virus is not a food safety or human health risk. It doesn’t affect other animals besides pigs. But it is considered to be a significant production disease and Ontario law makes it mandatory to report the disease to the Ontario agriculture ministry. PED virus wipes out almost all nursing piglets but older animals can recover.

In an article on the Veterinary Research website, University of Minnesota researchers say they’ve demonstrated the porcine epidemic virus (PED) can become airborne and remain infectious in the air, and that the virus’s genetic material can be transported for long distances following natural infections. The researchers say to their knowledge theirs is the first report to establish PED virus can be found in the air and that suspended airborne particles can be infectious.

Veterinary Research says on its website it is an open access journal that publishes high quality and novel research along with reviewing articles focusing on infectious diseases.

DeGroot says the location of the studies in the United States may have been a factor in the findings. “I know the studies were conducted in Oklahoma in a very pig-dense location with large sow farms and very humid conditions,” he notes. “That’s a very different weather type than what we get here sometimes.”

The Minnesota University researchers say further studies are now needed to assess the risk of airborne transmission of PED virus among farms and the need to address this route in biosecurity and health control programs.

DeGroot says the research on airborne transmission of the virus “shouldn’t change any biosecurity protocols. I think we’re still looking at a virus that transmits mostly by what they call the fecal-oral route. We’re looking at manure contamination or contaminated surfaces,” such as boots, equipment or transport trailers. But the surfaces don’t necessarily need to have visible manure on them to be contaminated with the virus. Sometimes “there could be microscopic viruses that we’re dealing with here,” he says.

Ontario farmers don’t need to change their heightened biosecurity protocols for now because of these new findings. DeGroot says factors about the virus that they’ve known about for awhile still apply, such as the virus survives better outside of a pig in cold temperatures.

So far in Ontario there have been 63 confirmed cases on farms since Jan. 22 when the first farm in Middlesex County was confirmed to have the virus. The virus has also been circulating in the United States since April 2013. BF