DETECTION OF DIFFERENT VIRUSES IN PORCINE ABORTION MATERIAL

Background and Objectives Abortion in sows occurs worldwide. The cause of abortion is often difficult to identify, especially when it comes to infectious diseases. Material and Methods We investigated abortion material from 93 different farms over 2 years (2021: 55; 2022: 38) by PCR for the occurrence of porcine viruses known being involved in abortion: porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus (PCV) 2, PCV3, PCV4, encephalomyocarditis virus (EMCV), porcine parvovirus (PPV), porcine teschovirus (PTV), porcine sapelovirus (PSV). PPV was only investigated in cases with mummified foetuses (n=25/93). Results EMCV, PCV4 and PPV could not be detected. In total, 36.6% (34/93) of investigated samples resulted in at least one positive PCR reaction. Highest detection rate was found for PCV2 (27.7%) with viral loads of 104 to 1012 genome equivalents (GE) per gram tissue followed by PRRSV (10.8%), PCV3 (5.4%) with viral loads of 102 to 1011 GE/g tissue, PTV (3.2%) and PSV (1.1%). In three cases double infections were diagnosed with involvement of PRRSV, PCV2, PCV3 and PTV each in different combinations. One sample showed positive PCR results for PRRSV, PSV and PTV and another one for PRRSV, PCV2, PCV3 and PTV. Discussion and Conclusion This study shows that viruses can be regularly detected in porcine abortion material. Most prevalent virus species is PCV2 followed by PRRSV possibly also reflecting their active involvement in abortion. However, when looking at the viral load of PCV2 in foetal hearts, only six samples reached the threshold of 109 GE/g tissue as value with most probable clinical relevance. For PCV3 no threshold values are available for interpretation, therefore histopathologic investigations are still needed for final diagnosis to confirm clinical relevance. Since PTV and PSV was only detected in 3 or 1 specimen respectively, it seems there is only little relevance in abortion cases in Austrian sows.