Manure-borne PEDv (porcine epidemic diarrhea virus) survival in soil

The porcine epidemic diarrhea virus (PEDv) outbreak in the US has had a significant impact on swine production in recent years.  Although strictly limited to pigs and hence poses no threat to other animals or humans, it is easily transmitted to suckling piglets where it causes nearly 100% mortality.  Manure can remain a source of the virus in pig production settings, so proper management and disinfection practices need to be developed and evaluated.  Human biosolids are often treated with lime to kill pathogens, therefore a series of incubation were initiated to examine how lime coulld be used to control PEDv in swine manure.  Lime source (ag lime vs. quick lime), various incubation times in manure slurry, and a soil incubation trial mimicing the climate in three US regions was conducted to simulate current manure application practices and its affect on PEDv survival.  PEDv survival was monitored by RNA extraction followed by quantitative rtPCR and was compared to live swine bioassays.  Initial results indicate that quick lime addition to manure slurry storages quickly inactivates virus and would be an excellent management tool to control potential re-infection.  However, ammonia losses from the manure storage would be substantial to do increased pH.