SHIC-Funded Research Identifies Potential Role of PPV2 in PRDC Development

Discovered in 2001, porcine parvovirus 2 (PPV2) is prevalent in swine worldwide. A recently completed Swine Health Information Center (SHIC)-funded research project on PPV2 confirmed the high prevalence of PPV2 in diseased pigs and provided insight into its significance in porcine respiratory disease complex (PRDC). Results supported PPV2 as one of the primary viral pathogens in the natural development of PRDC, particularly in weaned to finishing pigs.

Identifying high levels of PPV2 in the lung of a pig with pneumonia led researchers to seek SHIC funding so this investigation into its role in respiratory disease could begin. In the final research report, researchers said PPV2 was detected in 39% of lungs submitted for routine diagnostic testing. There was a significant positive correlation between PPV2 viral load and pig age. Histologically, PPV2 was mainly detected in alveolar macrophages in 28% of lungs with interstitial pneumonia, with PPV2 viral load tending to correlate with the number of macrophages in the lungs. While co-infections with PPV2 and established swine respiratory pathogens influenza A virus and porcine reproductive and respiratory syndrome virus (PRRSV) were commonly detected, assessment of viral loading and tissue locations showed no obvious association between PPV2 and other viral pathogens. Relatedly, in a third of PPV2 positive lungs analyzed by metagenomic sequencing, no other pathogens were identified.

SHIC, launched in 2015 with Pork Checkoff funding, continues to focus efforts on prevention, preparedness, and response to novel and emerging swine disease for the benefit of US swine health. As a conduit of information and research, SHIC encourages sharing of its publications and research. Forward, reprint, and quote SHIC material freely. SHIC is funded by America’s pork producers to fulfill its mission to protect and enhance the health of the US swine herd. For more information, visit http://www.swinehealth.org or contact Dr. Sundberg at psundberg@swinehealth.org.