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

Background: Infection 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 degrees C, as well as the survival on four different surfaces (galvanized steel, stainless steel, aluminum, and plastic). Results: Overall, there were no differences (P > 0.05) in virus survival among the different feed matrices studied when thermally processed at 60 to 90 degrees 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 degrees C (3. 7 min), 80 degrees C (2.4 min), and 90 degrees C (2.3 min) compared with 60 degrees C (4.4 min). The maximum inactivation level (3.9 log) was achieved when heating all ingredients at 90 degrees 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. Conclusions: The 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.