Evaluation of Time and Temperature Sufficient to Inactivate PED Virus in Swine Faeces on Metal Surfaces

In a new study at Iowa State University, heating scraped, unwashed aluminium trays to 71°C for 10 minutes or allowing them to sit for seven days at room temperature may be sufficient to prevent transmission of the porcine epidemic diarrhoea (PED) virus present in pig faeces.

15 April 2015

3 minute read

By: Jackie Linden

In the current issue of Journal of Swine Health and Production, Dr Paul Thomas of Iowa State University College of Veterinary Medicine and co-authors there and with AMVC Management Services and USDA Agricultural Research Service report their work to determine temperature and time applications sufficient to inactivate PED virus (PEDV) on a commercial livestock trailer, and practical within the constraints of current thermo-assisted drying and decontamination (TADD) capabilities in the industry.

They inoculated 32 four-week-old barrows via oral gastric tube with 5mL as follows:

PEDV-negative faeces (Neg; n=4)
untreated PEDV-positive faeces (Pos; n=4)
PEDV-positive faeces subjected to 71°C for 10 minutes (71C-10M; n=4)
PEDV-positive faeces subjected to 63°C for 10 minutes (63C-10M; n=4)
PEDV-positive faeces subjected to 54°C for 10 minutes (54C-10M; n=4)
PEDV-positive faeces subjected to 38°C for 12 hours (38C-12H; n=4)
PEDV-positive faeces subjected to 20°C for 24 hours (20C-24H; n=4), or
PEDV-positive faeces subjected to 20°C for 7 days (20C-7D; n=4).

These pigs served as a bioassay to determine the infectivity of virus following treatment.

Bioassay results were determined by reverse-transcriptase polymerase chain reaction on rectal swabs collected from the inoculated pigs on days 3 and 7 post inoculation.

None of the pigs in the 71C-10M or 20C-7D groups became infected with PEDV. This result differed significantly from that of the Pos group (P<0.05).

Results of the other groups did not differ significantly from that of the Pos group (P>0.05).

Thomas and co-authors concluded that holding PEDV in the presence of faeces at 71°C for 10 minutes or at 20°C (room temperature) for seven days is sufficient to inactivate the virus, preventing transmission under the conditions of this study.

Reference

Thomas P.R., L.A. Karriker, A. Ramirez, J.Q. Zhang, J.S. Ellingson, K.K. Crawford, J.L. Bates, K.J. Hammen and D.J. Holtkamp. 2015. Evaluation of time and temperature sufficient to inactivate porcine epidemic diarrhea virus in swine feces on metal surfaces. J Swine Health Prod. 2015;23(2):84-90.