Assessment of temperature and holding times to inactivate PRRSV and PEDV on contaminated surfaces commonly found in supply entry rooms in swine farms
Pedro Mil-Homens, Mafalda
Is Version Of
Fomites can be responsible for virus introduction in swine farms, which highlights the importance of implementing practices such as cleaning and disinfecting, using ultraviolet C light chambers or applying combinations of time and temperature to minimize the probability of virus introduction. The objective of the study was to assess the efficacy of different combinations of temperatures and holding times to inactivate PRRSV and PEDV on cardboard and diamond plate aluminum, surfaces that are commonly found at supply entry rooms in swine farms. An experimental study was conducted to assess the effect of time and temperature on two PRRSV strains and PEDV inactivation on cardboard and diamond plate aluminum. A total of 2 negative controls and 144 treatments with PRRSV MN 184, PRRSV 144 L1C Variant and PEDV were subjected to four different temperatures (20ºC, 30ºC, 40ºC, and 50ºC), and six time-settings (15 minutes, 60 minutes, 6 hours, 12 hours, 24 hours, and 36 hours). Virus titration followed by immunofluorescent staining were implemented after the virus recovery, and the cytopathic effect was observed. The time that it took for the virus to stop being detected, Weibull curves were calculated. Virus was detected at 20ºC after 36 hours, after 15 minutes and after 60 minutes, virus was not detected on aluminum surfaces at 50ºC. The results from the least-squared means suggest that the minimum time that surfaces should be held to stop getting virus detection at 30ºC was 24 hours, at 40ºC was 12 hours and at 50ºC was 6 hours, and that aluminum surfaces take longer to reach the desired temperature.