Alkaline stabilization of manure slurry inactivates porcine epidemic diarrhea virus

Authors: STEVENS, ERIN - University Of Nebraska; Miller, Daniel; BRITTENHAM, BETHANY - University Of Nebraska; VITOSH-SILLMAN, SARA - University Of Nebraska; BRODERSEN, BRUCE - University Of Nebraska; Jin, Virginia; LOY, JOHN - University Of Nebraska; SCHMIDT, AMY - University Of Nebraska

Submitted to: Swine Health and Production
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2017
Publication Date: 3/1/2018
Citation: Stevens, E.E., Miller, D.N., Brittenham, B.A., Vitosh-Sillman, S.J., Brodersen, B.W., Jin, V.L., Loy, J.D., Schmidt, A.M. 2018. Alkaline stabilization of manure slurry inactivates porcine epidemic diarrhea virus. Swine Health and Production. 26:95-100.

Interpretive Summary: The porcine epidemic diarrhea virus (PEDv) outbreak in North America has substantially impacted swine production. Since the virus is shed in feces, manure may remain a source of reinfection. Quicklime is used to control pathogens in human biosolids by raising pH and might control PEDv in swine manures in a similar way. Two laboratory studies examined how increasing amounts of quicklime affected PEDv. Molecular detection methods and swine bioassay were used to enumerate the virus and to determine whether it remained infectious. Quicklime additions that increased manure slurry to pH 10 or higher not only decreased PEDv abundance, but also inactivated PEDv. With higher pH to control PEDv, ammonia emissions may also increase and be an undesirable consequence. Quicklime treatment would be a recommended management tool to help limit potential PEDv infection from manure sources containing the virus.

Technical Abstract: The porcine epidemic diarrhea virus (PEDv) outbreak in North America has substantially impacted swine production since it causes nearly 100% mortality in infected pre-weaned piglets. The PED virus is transmitted via the fecal oral route and manure may remain a source of reinfection; therefore, proper manure management practices to limit outbreaks need to be developed and evaluated. Two laboratory studies simulating manure pit treatment with increasing amounts of quicklime were conducted to determine PEDv susceptibility to increasing pH. Quantitative PCR and live swine bioassay were used to enumerate PED virus and to determine PEDv infectivity. PEDv sequences were detected in all manure slurry samples (both control and quicklime treated), but liming manure slurry to pH 10 or higher not only decreased PEDv abundance, but also inactivated PEDv; pigs exposed to pH 10 or higher treated manure showed no indication of disease. Enhanced ammonia emissions above pH 9.25 may be an undesirable consequence. Quicklime treatment of PEDv manure slurry would be a recommended management tool to help limit potential infection from manure sources.