It struck suddenly, last May, at a hog farm in Ohio. Now, a year later, it has spread to 30 states around the United States, wiping out 10 percent of the U.S. pig population. The virus, known as porcine epidemic diarrhea virus, or PEDv, targets the lining of a pig’s small intestine, causing extreme diarrhea. It’s highly contagious, extremely potent (a tablespoon of PEDv is enough to wipe out the entire U.S. hog herd) and spreads by contact with infected manure or feed. Nearly every pig infected will die – it has already killed 7 million of America’s 63 million pigs sending pork prices through the roof.
The PEDv virus is nearly identical to one that infected pigs in China’s Anhui province but scientists have been unable to determine how the virus entered the United States. Some countries, including China, have already banned pig imports from the U.S. The disease has taken root in Canada too.
Tony Forshey, chief of animal health at the Ohio Department of Agriculture, explained how the virus kills its prey:
“The virus acts like a lawn mower on the villi in a pig’s intestines, which are the tiny projections that aid digestion. With their villi gone, the piglets cannot absorb nutrients from food or water, contract diarrhea and die from dehydration.”
PEDv thrives in cold, damp environments and last year’s deep winter may have accelerated its spread. Of nearly 15,000 samples taken by the USDA, about 1/3 produced positive results for the virus. In response, the pig industry has implemented stringent controls in an effort to stem the tide. Outside visitors have been banned from hog farms across the United States while some farms are even requiring workers change clothes before entering and leaving barns. Truck drivers have been instructed to wipe down the steps into their cabs, disinfect their steering wheels and change boots or wear disposable booties before entering farmyards. Some farms require truck drivers to stay inside their vehicles at all times.
So far, no vaccine has been able to protect the pigs and bright yellow signs marked “PED” are popping up outside farms warning the virus is present. Researchers have told the public to keep their fears at bay – in its current state, the virus poses no threat to humans. Still, some scientists fear if it evolves, it could produce an even more catastrophic event across the country.