Is Canine Parvovirus 2 a Potential Risk to the U.S. Swine Herd?
A lung tissue from a U.S. pig revealed the the first known detection of canine parvovirus 2 (CPV2) after diagnostic laboratory sequencing in October 2020. This unexpected detection of CPV2 was assumed to be an incidental finding in lung tissue lacking significant lesions and not a contributor to disease, reports the Swine Health Information Center. Nonetheless, SHIC funded research to determine if CPV2 could be an emerging disease risk to the U.S. swine herd.
What is CPV2?
CPV2 is a non-enveloped single-stranded DNA virus that infects domestic dogs globally, resulting in gastrointestinal disease and immunosuppression, SHIC says. However, CPV2 originated from a cross-species transmission of feline parvovirus into dogs over 40 years ago and has been detected in many wildlife species since.
Determining the Risk to Swine
Ben Hause, assistant professor at South Dakota State University, led the SHIC-funded research project with three objectives to determine the cross-species transmission and pathogenesis risk to swine.
1. Tissues previously submitted to the diagnostic lab from U.S. 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).
2. Serum samples previously submitted to the diagnostic lab from U.S. 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).
3. 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, SHIC reports.
Although CPV2 is capable of spillover into swine, research showed the virus does not appear to be highly pathogenic to pigs. Continued vigilance of the industry is needed, SHIC says, as mutations of CPV2 over time may alter the epidemiological situation and increase the disease risk to U.S. swine.
More from Farm Journal's PORK:
Porcine Circovirus 3: Why SHIC is Seeking a U.S. Case Definition
SHIC-Initiated Swine Disease Reporting System Continues to Expand with PCV2