Detection and quantification of PCV-3 in Austrian pigs using duplex Real-Time PCR

Porcine circovirus 3 (PCV-3) is a circular DNA-Virus, which was first discovered in swine in the USA in 2015. It beiongs to the family Circoviridae, together with porcine circovirus 1, 2 and 4. PCV-3 is distributed globally and has Been detected in severa) European, Asian and American countries. The pathogenicity of this virus is stil) controversial. In this study, a published PCV-3 real-time PCR method was improved by inciusion of a parallei endogenous control assay, in order to be better suited to testing clinicai sampies (PCV-3/(3-Actin dupiex Real Time PCR), and validated. Using this test, clinicai sampies from Austrian pigs were subsequentiy screened for the presence of PCV-3 DNA. A sensitive (limit of detection: 25 copies/PCR) and specific dupiex real-time PCR for the detection of PCV-3 and (3-Actin as endogenous control was established. Afterwards, 27 sera from heaithy boars, as well as 30 sera and 119 tissue poois from sick pigs of different ages and 41 tissue poois from aborted pig fetuses were tested for PCV-3. Finally, 15.4 % of sera from heaithy pigs, 6.7 % of sera and 12.6 % of tissue poois from sick pigs as well as 9.8 % of aborted fetuses were tested positive for PCV-3.The highest virai load (9.1 x 108 copies/mi) was observed in an aborted fetus, while ali PCV-3 positive sera remained beiow the limit of quantifica-tion (250 copies/PCR).