Porcine circovirus: a serological survey of swine in the United States.

Summary: An indirect-fluorescent antibody procedure was used to assay swine serum for the presence of porcine circovirus (PCV)antibodies. We tested sera from II Georgia swine herds, one herd from North Carolina and one herd from Iowa.Antibodies against PCV were found in an average of 53 % of the samples tested. The incidence varied from a low of 2 7 % to a high of 100%.The antibody titers on one of the farms varied from 1:8 to 1:256.A titer of 1:8 or greater is considered to be positive. The significance of PCV infections has not been determined and further studies are needed to determine the possible role this virus might have in disease. B ecause porcine circovirus (PCY) infections in the United States have not been documented, we conducted a serological survey to determine whether these infections also occur in this country. Serological surveys in Germany ' and Canada2 indicate that the virus is indigenous to those countries. Porcine circovirus is an extremely small virus that contains a circular single-stranded DNA.First characterized in 1982,3 PCYwas originally isolated as a contaminate of the PK-15 cell line obtained from the American Type Culture Collection (Cat. # ATCC CCL 3). The virus is 17 nm in diameter, and the single stranded circular DNAcontains about 1760 nucleotide bases.3 The virus is very similar to the beak-and-feather disease virus (PBFDY) of psittacine birds and also closely resembles the chicken anemia virus (CAY)of chickens.4 The results of the serological surveyin Germany!demonstrated that 85 % of swinefrom three slaughter houses were positivefor PCYantibodies. A breeding group of mini-pigs had a positive incidence rate of 36%, and fiveof eight wild boars (62%) were positive. Dulac and Afshar2reported an incidence of 55 % in commercial herds and 26 % from a slaughterhouse. Theyfound that a specific-pathogen-free (SPF) herd was negative for PCY antibodies.