Reconsideration of the diagnostic criteria required for PCV2 reproductive disease

Vet J. 2021 Jun:272:105660. doi: 10.1016/j.tvjl.2021.105660. Epub 2021 Mar 23.

Abstract

Porcine circovirus type 2 (PCV2) causes a variety of clinical conditions including PCV2-associated reproductive disease (PCV2-RD) characterized by late term abortions and mummifications. The generally accepted diagnostic triad includes the presence of reproductive disorders, the histopathological finding of myocarditis, and detection of moderate to high viral loads within the heart tissue. A new threshold of 109 PCV2 genome equivalents (GE)/g heart tissue is suggested to fulfil the third criterion using the diagnostic settings of quantitative real time PCR and in situ hybridization of 30 fetal heart tissues. The need to identify histopathological lesions in fetal heart tissue appears to be invalid or overestimated in confirming a diagnosis of PCV2-RD, at least at the individual fetus level. The highest viral loads (1012 GE/g tissue) were detected in autolyzed and mummified piglets and were identified as PCV2d, although concurrent detection of PCV2d + a and PCV2d + b also occurred.

Keywords: Diagnostics; Histological fetal heart lesions; In situ hybridization; Porcine circovirus 2 reproductive disease; Quantitative PCR.

MeSH terms

  • Abortion, Veterinary / diagnosis
  • Abortion, Veterinary / virology
  • Animals
  • Circoviridae Infections / diagnosis
  • Circoviridae Infections / pathology
  • Circoviridae Infections / veterinary*
  • Circovirus*
  • Female
  • Fetal Death / etiology
  • Pregnancy
  • Pregnancy Complications / diagnosis
  • Pregnancy Complications / veterinary*
  • Pregnancy Complications / virology
  • Swine
  • Swine Diseases / diagnosis*
  • Swine Diseases / pathology
  • Swine Diseases / virology*