Porcine Circovirus

Porcine circovirus (PCV) infections associated with post-weaning multisystemic wasting syndrome (PMWS) are characterized by weight loss, respiratory distress, jaundice, etc. Although PCV2 infection is ubiquitous, the prevalence of clinical disease is lower and the most common form is PCV2 subclinical infection. Recently, a novel porcine circovirus (PCV3) has been identified in pigs in the USA that is associated with porcine dermatitis nephropathy syndrome, acute myocarditis and multisystemic inflammation, etc. Genetic heterogeneity of PCV2 has been studied in Indian pig population. Different genotypes like PCV2a-2D, PCV2b-1C, PCV2d and recombinant strain between PCV2a-2C and PCV2b-1C are reported from different studies. PCV2 has been discovered in human faeces, human vaccines and beef. But its pathogenicity in humans is not clear. PCV detection is based on common golden standard techniques including nucleic acid and antigen detection in the tissues, in situ hybridization (ISH) and immunohistochemistry (IHC) using monoclonal or polyclonal antibody against PCV2, respectively. The commercial vaccines available are effective in reducing the severity of clinical diseases and improving production parameters. Recently, antiviral compounds have also shown promising results against PCV2. This chapter summarizes aetiology, epidemiology, transmission, immunopathobiology, diagnosis, prevention and control of porcine circovirus.