Since it was first detected in the United States in 2013, porcine epidemic diarrhea virus (PEDV) has spread rapidly across much of the swine industry causing catastrophic losses in suckling pigs. As the manure pumping season of 2014 draws closer and closer, little was known about how long this virus is able to survive in swine manure and if we are at high risk of spreading this virus during manure hauling. Therefore, the veterinarians and researchers at Swine Veterinary Center of St. Peter, MN, led by Steve Tousignant, DVM, designed a study to begin to shed some light on this question.
During the last week of August leading into the first week of September, a total of 30 sites were sampled. Fifteen of these were sites that had PEDV-positive pigs placed approximately six months before sampling (pigs were placed at the end of February through early March) and another 15 sites with positive pigs placed approximately four months before sampling (end of April through early May). At each site, manure was collected through pit pump-outs, and tested for the presence of live virus using swine bioassay. Of the 30 samples, there were two that tested positive for live virus from sites that were filled with PEDV-positive pigs four months ago. All other samples did not contain live virus.
This study begins to shed light onto the question of how long PEDV can survive in swine manure. This data supports previous pit-pumping recommendations. Whenever possible, it is best to pump healthiest, disease-free sites first. Continue sequencing pumping locations so the last sites pumped are the ones that have had disease challenges. Try to pump the sites most recently infected with PEDV last.
Additionally, good hygiene should continue to be promoted between sites including washing and disinfecting vehicles, tools and equipment. Communication with neighbors is essential. Try to apply manure (especially if from disease-challenged sites) as far away from other farms as possible, even consider manure exchanges when necessary. With the efforts of everyone working together, it is hopeful that the frequency of spreading PEDV through manure hauling and application in the fall of 2014 will be low.
The National Pork Board and the U.S. Department of Agriculture provided funding for this project.