Survival of porcine epidemic diarrhea virus (PEDV) in thermally treated feed ingredients and on surfaces

Abstract

BackgroundInfection with Porcine Epidemic Diarrhea Virus (PEDV) causes vomiting, diarrhea, and dehydration in young pigs. The virus made its first appearance in the U.S. in 2013, where it caused substantial neonatal mortality and economic losses in the U.S. pork industry. Based on outbreak investigations, it is hypothesized that the virus could be transmitted through contaminated feed or contaminated feed surfaces. This potential risk created a demand for research on the inactivation kinetics of PEDV in different environments. Therefore, the objective of this study was to evaluate the survival of PEDV in 9 different feed ingredients when exposed to 60, 70, 80, and 90 °C, as well as the survival on four different surfaces (galvanized steel, stainless steel, aluminum, and plastic).ResultsOverall, there were no differences (P > 0.05) in virus survival among the different feed matrices studied when thermally processed at 60 to 90 °C for 5, 10, 15, or 30 min. However, the time necessary to achieve a one log reduction in virus concentration was less (P < 0.05) when ingredients were exposed to temperatures from 70 °C (3.7 min), 80 °C (2.4 min), and 90 °C (2.3 min) compared with 60 °C (4.4 min). The maximum inactivation level (3.9 log) was achieved when heating all ingredients at 90 °C for 30 min. There were no differences in the amount of time necessary to cause a one log reduction in PEDV concentration among the different surfaces.ConclusionsThe results of this study showed that PEDV survival among the 9 feed ingredients evaluated was not different when exposed to thermal treatments for up to 30 min. However, different combinations of temperature and time resulted in achieving a 3 to 4 log reduction of PEDV in all feed ingredients evaluated. Finally, PEDV survival was similar on galvanized steel, stainless steel, aluminum and plastic.

The Role of Non-animal Origin Feed Ingredients in Transmission of Viral Pathogens of Swine: A Review of Scientific Literature

“…Collectively, the findings indicate that none of the source ingredients nor the outgoing feed at the feed mills sampled were positive for viral RNA, suggesting the non-animal origin ingredients and feed were not contaminated with PEDV or PDCoV. However, experimental studies by Trudeau et al (33, 34) did show that feed ingredients, soybean meal in particular, spiked with PEDV, PDCoV, and TGEV in a laboratory setting could maintain live virus for a period of time at room temperature. The authors also found that different ingredients supported different virus survival periods which they believe may be due to differences in moisture content, ether content and/or pH of each ingredient.…”

“…Trudeau et al (33, 34) conducted experimental studies to investigate inactivation kinetics of PEDV, PDCoV, and TGEV in feed and feed ingredient matrices and on solid surfaces. Feed and non-animal origin feed ingredients used in these studies included complete feed, corn, soybean meal, corn dried distillers grains with solubles, and vitamin and trace mineral premix.…”

“…The authors found no difference in virus survival in feed and non-animal origin feed ingredients incubated at temperatures higher than 70°C. The maximum level of virus inactivation occurred upon heating the spiked samples at 90°C for 30 min (33, 34).…”

The Canadian 2014 porcine epidemic diarrhoea virus outbreak: Important risk factors that were not considered in the epidemiological investigation could change the conclusions

“…Original research (Dee, Clement, et al, ; Dee, Neill, Clement, Christopher‐Hennings, & Nelson, ; Dee et al, ) and recent review papers (Gordon et al, ; Jones, Woodworth, Dritz, & Paulk, ; USDA APHIS, ) have begun to identify and assess the risk of feed and non‐animal feed ingredient as potential fomites for spreading virus. For example, PEDV has been shown to survive for extended periods of time on conventional and specialty soybean meal (Dee et al, , ; Trudeau, Verma, Sampedro, et al, ; Trudeau, Verma, Uriolla, et al, ). Current biosecurity protocols for sourcing, transport and receiving bulk feed ingredients have been enhanced relative to those in place prior to the introduction of PEDV into North America (AFIA, ; ANAC, ; National Pork Board, ).…”

“…Independent trials demonstrate that, depending on storage temperatures, PEDV inoculated on SDAP does not survive over 1–3 weeks (Dee et al, ; Pujols & Segalés, ; Trudeau, Verma, Uriolla, et al, ). The SDPP investigated by CFIA was produced over 10 weeks before the Index case and over 13 weeks before CFIA collected their sample (NASDBPP, ).…”