US - A recent study of Senecavirus A offers valuable new insights into this increasingly important disease pathogen to the US pork industry.
This work, partially funded by the Swine Health Information Center (SHIC), led by Dr Diego G. Diel, DVM, MS, PhD, South Dakota State University, has uncovered more information about the infection biology and pathogenesis of the virus that may help to ease detection, and ultimately, control of the tenacious virus, reports the AASV.
“This study provides significant insights on the pathogenesis and infectious dynamics of SVA in swine,” Dr Diel said.
“In addition to confirming findings of previous studies that demonstrate the role of SVA as the causative agent of vesicular disease in pigs, our study shows that SVA is shed in oral and nasal secretions and feces of infected animals for up to four weeks post-infection.”
Study Finds Tonsil Is One Primary Target Tissue
Clinical signs characterised by lethargy and lameness were first observed four days post-inoculation and they persisted for about two to 10 days. Vesicular lesions were observed on the snout and feet, affecting the coronary bands, dewclaws, interdigital space and heel/sole of SVA-infected animals.
In addition, the investigators detected a short-term viremia between days 3 to 10 post-inoculation. Also, they found virus shedding between days 1 to 28 post-inoculation in oral and nasal secretions and feces.
Interestingly infectious SVA was consistently recovered from the tonsil during the first seven days of infection and, the virus RNA was detected in the tonsil of all SVA-infected animals using real-time quantitative PCR and in situ hybridization (ISH) performed on tissues collected on day 38 post-inoculation.
Serological responses to SVA were characterised by early neutralising antibody responses (5 days post-inoculation), which coincided with a progressive decrease in the levels of viremia, virus shedding and viral load in tissues.
“We have shown that SVA has a predilection for lymphoid tissues with the tonsil being one of the main targets of virus replication,” Dr Diel said.
“These results provide an improved understanding of SVA infection biology and may lead to enhanced prevention and control strategies in the future.”
You can view the full report by clicking here.
ThePigSite News Desk