Today, we are sharing a recent publication from a UMN VDL team led by Dr. Albert Rovira regarding porcine circovirus type 3 (PCV3) and its prevalence among UMN VDL submitted cases in recent years. The full article is available on the Journal of Veterinary Diagnostic Investigation website.
Materials and Methods
- 730 case submissions from 2016-2018 in which at least one PCV3 PCR was done.
- These cases represented 2,177 samples from 474 sites in 21 states.
- PCV3 frequency was calculated and broken down by state.
- Association of PCV3 with clinical signs, histologic lesions, and age
- Special emphasis on fetal death cases
Overall, 35% of the cases and 27% of the samples were PCV3 positive.
North-Carolina, South Dakota and Nebraska had the highest percentage of PCV3-positive samples. (73%, 50%, and 45% respectively)
The majority of specimen types tested positive for PCV3 PCR at least once. Oral fluids and processing fluids had the highest percentage of positive PCR tests among the commonly submitted sample types.
PCV3 was detected in around 50% of the adult pig samples whereas it was detected in only 15-20% of the samples from other age groups including fetuses.
Co-detection of PCV3, PRRS and PCV2 was overall uncommon with the maximum frequency found in adult pigs (16-29%).
Out of the 64 fetal death submissions, 70% were negative for all tested viruses. PCV3 was the most commonly found virus (22% of cases) in this dataset.
Porcine circovirus 3 (PCV3) is widespread in pigs worldwide. Diverse clinical signs and lesions have been associated with PCV3, but the role of PCV3 as a cause of disease in swine remains unclear. We investigated the association of PCV3 with clinical signs and histologic lesions in 730 diagnostic swine cases between February 2016 and January 2018. The cases contained 2,177 samples submitted from 474 sites located in 21 states in the United States. PCR assay results were positive for PCV3 for 577 of 2,177 (27%) samples, 255 of 730 (35%) cases, 181 of 474 (38%) sites, and 17 of 21 (81%) states. We detected PCV3 in 19 of 28 specimen types and in pigs of all ages and clinical presentations, including healthy pigs, with the highest detection rate in adult pigs. PCV3 detection was not associated with respiratory, gastrointestinal, or CNS signs, weight loss, or sudden death. Of 58 types of histologic lesions evaluated, PCV3 detection was associated with myocarditis, cardiac vasculitis, and interstitial pneumonia in growing pigs. A high PCV3 detection rate was observed in aborted fetuses.