CategorySwine Health - General Disease
Date Full Report Received
Date Abstract Report Received
Seneca virus A (SVA) is clinically indistinguishable from other vesicular diseases such as foot-and-mouth disease virus (FMDV). Since 2015, the Iowa State University Veterinary Diagnostic Laboratory (ISUVDL) has experienced an increased number of SVA positive swine cases and while SVA has little impact on production and is not a reportable disease, swine veterinarians in the United States are required to report animals exhibiting vesicular lesions to State or Federal animal health officials. The increased incidence of SVA has stressed state and federal resources to conduct FAD investigations and has reduced the sense of urgency when vesicular lesions are observed because of the assumption “it is just SVA”. Carrying agents that are either infected or contaminated with live virus may transmit SVA, as well as other swine pathogens, from one herd to another. One approach to reducing the risk of transmitting the virus is to mitigate the contamination of carrying agents after they become contaminated. Ultraviolet C (UVC) light disinfection has been applied in many industries including human medicine and food processing, but the practical application of the technology in livestock production has not been well studied. Despite the lack of research, the technology is increasingly being used on swine farms. UVC disinfection is potentially an economically feasible, easily managed, effective way to mitigate risk associated with the entry of carrying agents contaminated with SVA and other viruses.
The objective of this study is to evaluate the efficacy of UVC for inactivating Seneca virus A (SVA) on three different contaminated surfaces (cardboard, cloth and plastic) commonly found in swine farms under challenged conditions.
An experimental design study under controlled conditions assessed the effect of UVC on a SVA isolate on three different surface types: cardboard, cloth and plastic. Each coupon was inoculated with 1 ml of SVA and 1 ml of PBS or 1 gram of feces on the top or bottom surface of the coupon and allowed to dry. Coupons were exposed to UVC in a commercially available pass through chamber (PTC) for 5 minutes or in a simulated supply entry room (SER) for 120 minutes face up or face down on a metal wire shelf. After exposure, virus was recovered from each coupon and virus titration was performed on the sample collected. Virus log titer reductions of the UVC treated groups were compared to their relative positive controls.
The plastic coupons inoculated with SVA and PBS had a significantly lower virus log titer, (>7 log virus titer reduction) in both the PTC and SER when compared to their relative positive controls. All other study groups had only a 2 log virus titer reduction or lower in the PTC and SER compared to their positive controls. There was no significant statistical difference between the UVC top and bottom inoculated surfaces. UVC was efficacious as a disinfection for SVA on plastic that was free of organic material. UVC has the potential to serve as an appropriate method of disinfection for SVA on materials that are free of organic material and non-permeable, such as plastic.