Location: Virus and Prion ResearchTitle: Experimental Seneca Valley virus infection in market-weight gilts
|BUCKLEY, ALEXANDRA - Oak Ridge Institute For Science And Education (ORISE)|
|KULSHRESHTHA, VIKAS - Orise Fellow|
|VAN GEELEN, ALBERT - Orise Fellow|
|MONTIEL, NESTOR - Animal And Plant Health Inspection Service (APHIS)|
|GUO, BAOQING - Iowa State University|
|YOON, KYOUNG-JIN - Iowa State University|
Submitted to: Veterinary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/11/2019
Publication Date: 2/13/2019
Citation: Buckley, A., Kulshreshtha, V., van Geelen, A., Montiel, N., Guo, B., Yoon, K.-Jin, Lager, K. 2019. Experimental Seneca Valley virus infection in market-weight gilts. Veterinary Microbiology. 231:7-10. https://doi.org/10.1016/j.vetmic.2019.02.019.
Interpretive Summary: Seneca Valley virus (SVV) causes a vesicular disease in swine that is recognized as a blister-like skin disease located around the hoof and on the snout, which looks the same as clinical disease caused by foot-and-mouth disease virus (FMDV). FMDV can rapidly spread among livestock and cause an economically devastating disease that can affect the food supply. Although the United States is free of FMDV, there is constant vigilance for this disease. Every time vesicular disease is observed, a foreign animal disease (FAD) investigation must occur; therefore, the dramatic increase of swine vesicular disease cases that began in 2015 in the United States is causing a strain on resources to complete these FAD investigations. This increase in SVV-related vesicular cases has raised questions about changes in the virus to explain the upsurge in cases. In order to better understand the pathogenesis of recent SVV isolates, a study was completed to better characterize early SVV infection in market-weight swine, which is the age group that is commonly affected in the field. Clinical signs were observed in some pigs in less than 48 hours after viral challenge and these lesions took 1-2 weeks to heal. Virus was detected in serum for around 1 week in most pigs after challenge and neutralizing antibodies development coincided with the disappearance of virus. This study has described the acute SVV infection in market-weight pigs, but additional studies are warranted to better understand the ecology of this FMDV look-alike disease.
Technical Abstract: Seneca Valley virus (SVV) is a picornavirus that causes vesicular disease in swine. Since it is clinically indistinguishable from vesicular disease caused by food-and-mouth disease virus (FMDV), investigations must be performed to rule out this high consequence pathogen. A large portion of these investigations have involved market-weight swine at slaughter plants. The objective of this study was to describe acute infection dynamics of market-weight gilts (8 months of age) experimentally infected with SVV. At 0 days post inoculation (dpi) all gilts (n=15) were given an intranasal SVV inoculation. Vesicular lesions on the coronary band were first observed on one or more feet by 2 dpi in 4 of the 15 gilts and in all by 5 dpi. Vesicles on the snout were observed in 6 of the 15 gilts beginning at 4 dpi. All gilts became viremic post challenge for about 7 days and developed anti-SVV neutralizing antibodies by 7 dpi. Most vesicular lesions were resolved by 14 dpi. Understanding the pathogenesis of SVV is critical in order to inform decisions that veterinarians and producers must make at the farm level to control this disease.