Time and temperature requirements for heat inactivation of pathogens to be applied to swine transport trailers

Objective: Biosecurity in swine transport trailers is of concern for spreading pathogens between premises, and as such, they require extensive cleaning and disinfection between loads. Our goal in this study was to find the optimal time and temperature required to heat inactivate swine pathogens of high concern to producers in a laboratory setting to then be extrapolated to transport trailers. Materials and methods: Using standard microbiological techniques for growth and purification, 5 bacterial and 5 viral pathogens important in swine health were produced and tested. Heat inactivation of these pathogens were tested in the lab using several time and temperature combinations. Fecal matter was added to test the effect of biological material on the time and temperatures required for inactivation. Results: Inactivation was complete for viruses and bacteria tested when heated to 75°C for 15 minutes. The presence of fecal matter resulted in increased time and temperature needed for pathogen inactivation. Implications: Heat baking of transport trailers is now being applied as a useful tool to reduce the transmission of pathogens commonly associated with swine disease. However, operators must ensure consistent heating to 75°C for a minimum of 15 minutes in all areas of the trailer for reliable inactivation. Cleaning trailers plays an important role prior to heat treatment, as the presence of fecal contamination will insulate the pathogens and inactivation may not be complete even at 75°C for 15 minutes.