Composting as a biosecure disposal method for PEDv-infected pig carcasses

Authors: SCHMIDT, AMY - University Of Nebraska; Miller, Daniel; LOY, JOHN - University Of Nebraska

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 2/16/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Porcine epidemic diarrhea virus (PEDV), an enteric disease of swine, has emerged as a worldwide threat to swine health and production. Little is known about virus persistence in PEDV-infected carcasses and effective disposal methods thereof. Two studies were conducted to quantify the persistence of PEDV RNA via quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) at various time-temperature combinations and in infected piglet carcasses subjected to composting. In the first study, PED virus was suspended in cell culture media at 1 x 105 TCID50 per sample (1 mL sample size) and subjected to time and temperature combinations in triplicate including temperatures of 37, 45, 50, 55, 60, 65, 70°C and exposure times of 0, 1, 2, 3, 4, 5, 7, and 14 d. At all temperatures, viral RNA copies declined over time, with the decline most marked and rapid for 65 and 70°C. Detectable RNA persisted in all but the most extreme condition; two of three samples incubated at 70°C yielded undetectable viral RNA after 14 d. In the second study, PEDV-infected piglet carcasses were subjected to two cycles of composting lasting 36 and 37 days, respectively. Composting was performed in triplicate windrow sections in biosecure, climate-controlled rooms using insulated bins designed to represent a continuous windrow. Compost samples collected at ten locations throughout the cross-section of windrow sections following each compost cycle yielded no detectable viral RNA. Composting appears to be an effective disposal method for PEDV-infected piglet carcasses under the conditions examined.