Circovirus infections in swine

Porcine circovirus (PCV) belongs to the Circoviridae family, a group of ani mal and plant pathogens, Circoviruses have short, circular single stranded DNA genomes, PCV is widespread in pigs world-wide and the infections are of ten subclinical, It has been recently documented that PCV is the etiologica l agent of infectious congenital tremor and postweaning multisystemic wasti ng syndrome (PMWS) in piglets, which primarily affects pigs between 6 and 8 weeks of age. The clinical signs include weight loss, tachypnea, dyspnea a nd jaundice, A new type of PCV has been identified, namely PCV2 in the orga ns of pigs exhibiting symptoms of PMWS. It has been demonstrated that PCV2 shares merely 69% nucleotide identity with nonpathogenic PCV1, which has be en found to be a common contaminating agent in the PK-15 cell line, Circovi rus infection diagnosis occurs mainly by direct detection of viral proteins or DNA in tissue sections and includes immunostating with mono- and polycl onal antibodies, in situ hybridization and polymerase chain reaction, It ha s recently been proposed that PCV together with another circovirus, namely beak-and-feather disease virus, are intermediates between family of geminiv iruses and plant circoviruses.