Pig Disease Spreading in the U.S. Porcine epidemic diarrhea virus (PEDV) has been spreading across the U.S. since earlier this month, according to health and government officials. The first case was diagnosed in mid-April. The strain is 99.4 percent similar to the strain found in China last year, which resulted in a loss of 1 million pigs. Older pigs aren't affected in the same manner as younger pigs -- though they do suffer symptoms that impact weight gain and can delay marketing by one to two weeks. Younger pigs face a mortality rate between 50-100 percent, which can wipe out a month's worth of pigs.The strain is not contagious for humans. Research studies are ongoing and include a new initiative from the National Pork Board. It is t...