In October 2020, diagnostic laboratory sequencing of lung tissue from a US pig revealed the presence of canine parvovirus 2 (CPV2). The unexpected detection of CPV2 was assumed to be an incidental finding in lung tissue lacking significant lesions and not a contributor to disease. However, since this was the first known detection of CPV2 in swine, SHIC funded research to determine if CPV2 may be an emerging disease risk to US swine.
CPV2 is a non-enveloped single-stranded DNA virus which infects domestic dogs globally, resulting in gastrointestinal disease and immunosuppression. However, CPV2 originated from a cross-species transmission of feline parvovirus into dogs over 40 years ago and has since been detected in many wildlife species. Led by Dr. Ben Hause, an Assistant Professor at South Dakota State University, the SHIC-funded research project had three objectives to determine the cross-species transmission and pathogenesis risk to swine.
First, tissues previously submitted to the diagnostic lab from US swine were screened for the presence of CPV2 genome using PCR. Approximately 13% of tissues had CPV2 detected at relatively low DNA levels (mean Ct = 31). Second, serum samples previously submitted to the diagnostic lab from US swine were screened for the presence of CPV2 antibodies using hemagglutination inhibition assays. Approximately 66% of serum samples had CPV2 antibodies detected at low levels (most titers ≤ 80). Third, colostrum-deprived one day old neonatal pigs were inoculated through the oronasal route with CPV2 to assess their ability to replicate the virus and the ability of CPV2 to induce disease. Experimentally inoculated swine did not appear to develop productive CPV2 infections.
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