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Historical Background

Porcine circovirus (PCV) was first recognized as a contaminant of the continuous pig kidney cell line PK-15 (ATCC-CCL31) in 1974 in Germany and described as picornavirus-like virus (Tischer et al., 1974). PCV is a very small, nonenveloped, single stranded DNA virus with a circular genome (Tischer et al., 1982). Under experimental conditions, the PCV-PK-15-isolate did not induce disease in pigs (Allan et al., 1995; Tischer et al., 1986). In the late 1990’s PCV was associated with a newly-emerged disease syndrome in pigs described as “postweaning multisystemic wasting syndrome” (PMWS) (Allan et al., 1998). Sequence analysis of the PMWS-associated PCV revealed differences compared to the earlier described PCV (Allan et al., 1998a; Allan et al., 1999; Ellis et al., 1998; Hamel et al., 1998; Meehan et al., 1998; Morozov et al., 1998). In order to distinguish the pathogenic PMWS-associated PCV from the non-pathogenic PCV, the pathogenic type was designated porcine circovirus type 2 (PCV2) and the non-pathogenic type as porcine circovirus type 1 (PCV1).

The presence of PCV2 can be traced back to 1985 in Canada (Magar et al, 2000), Belgium, and Spain (Rodríguez-Arrioja, 2003), to 1973 in Ireland (Walker et al., 2000), 1970 in the UK (Grierson et al., 2004), and 1969 in Belgium (Sanchez et al., 2000). Magar et al. (2000) tested 177 serum samples from 1985, 145 serum samples from 1989, and 147 serum samples from 1997. All sera were obtained from Canadian slaughterhouses and tested by immunofluorescence assay (IFA) for antibodies to PCV1 and PCV2. In 1985, 8% of the sera were positive for PCV1 and 13.6% were positive for PCV2. In 1989, 41.4% of the sera were positive for PCV1 and 72.4% were positive for PCV2. In 1997, 38.1% of the sera were positive for PCV1 and 66.7% were positive for PCV2 (Magar et al., 2000). Walker et al. (2000) detected PCV2-antibodies in the majority of pig serum samples collected in Northern Ireland from 1973 until 1999. The percentage of sera containing PCV2-antibodies showed an increased incidence in the samples collected in 1988 (100%; 80/80) and 1999 (92.1%; 129/140) when compared to 1973 (69.1%; 56/80), 1981 (61.3%; 49/80), and 1984 (55%; 44/80). Sporadic cases of PMWS were identified in archived tissues before the emergence of PMWS in the 1990’s. Grierson et al. (2004) reviewed formalin-fixed tissues from 68 porcine cases that had been submitted to a laboratory in England between 1970 and 1997 by PCR, open reading frame (ORF) 2-sequencing, and immunohistochemistry (IHC) for PCV2 specific nucleic acids and antigen. The authors found PCV2-specific nucleic acids in 41% (9/22) of submission from the 1990’s, in 31% (4/13) of submission from the 1980’s, and in 32% (8/25) of submissions from the 1970’s. Sequence analysis of 5 archived tissues revealed a high identity to PCV2 sequences obtained from a 2000 porcine dermatitis and nephropathy syndrome (PDNS) case implying that a similar PCV2 isolate has been present in the UK pig population for more than 30 years (Grierson et al., 2004). Rodríguez-Arrioja (2003) investigated archived tissues from 189 pigs for the presence of PCV2-DNA by in-situ-hybridization (ISH) and archived sera from 388 pigs for the presence of PCV2-specific antibodies by indirect immunoperoxidase monolayer assay (IPMA) collected from 1985 to 1997 in Spain and found 41.3% (78/189) tissues ISH positive and 72.7% (282/388) sera IPMA positive. This is indicative of enzootic infection in Spain since 1985 (Rodríguez-Arrioja, 2003b). Sanchez et al. (2001) tested 50 serum samples from 1969, 50 serum samples from 1975, and 50 serum samples from 2000 obtained in slaughter houses in Belgium. All serum samples were positive for PCV2-specific antibodies by IPMA (Sanchez et al., 2001).


Allan GM, McNeilly F, Kennedy S, Daft B, Clarke EG, Ellis JA, Haines DM, Meehan BM, Adair BM: Isolation of porcine circovirus-like viruses from pigs with a wasting disease in the USA and Europe. J Vet Diagn Invest. 10:3-10, 1998

Allan GM, McNeilly F, Cassidy JP, Reilly GA, Adair B, Ellis WA, McNulty MS: Pathogenesis of porcine circovirus; experimental infections of colostrum deprived piglets and examination of pig foetal material. Vet Microbiol. 44:49-64, 1995

Allan G, Meehan B, Todd D, Kennedy S, McNeilly F, Ellis J, Clark EG, Harding J, Espuna E, Bøtner A, Charreyre C: Novel porcine circoviruses from pigs with wasting disease syndromes. Vet Rec. 142:467-468, 1998a

Ellis J, Hassard L, Clark E, Harding J, Allan G, Willson P, Strokappe J, Martin K, McNeilly F, Meehan B, Todd D, Haines D: Isolation of circovirus from lesions of pigs with postweaning multisystemic wasting syndrome. Can Vet J. 39:44-51, 1998

Grierson SS, King DP, Sandvik T, Hicks D, Spencer Y, Drew TW, Banks M: Detection and genetic typing of type 2 porcine circovirus in archived pig tissues from the UK. Arch Virol. 149:1171-1183, 2004

Hamel AL, Lin LL, Nayar GPS: Nucleotide sequence of porcine circovirus associated with postweaning multisystemic wasting syndrome in pigs. J Virol. 72:5262-5267, 1998

Magar R, Müller P, Larochelle R: Retrospective serological survey of antibodies to porcine circovirus type 1 and 2. Can J Vet Res. 64:184-186, 2000

Meehan BM, McNeilly F, Todd D, Kennedy S, Jewhurst VA, Ellis JA, Hassard LE, Clark EG, Haines DM, Allan GM: Characterization of novel circovirus DNAs associated with wasting syndromes in pigs. J Gen Virol. 79:2171-2179, 1998

Morozov I, Sirinarumitr T, Sorden SD, Halbur PG, Morgan MK, Yoon KJ, Paul PS: Detection of a novel strain of porcine circovirus in pigs with postweaning multisystemic wasting syndrome. J Clin Microbiol. 36:2535-2541, 1998

Rodríguez-Arrioja GM, Segalés J, Rosell C, Rovira A, Pujols J, Plana-Durán J, Domingo M: Retrospective study on porcine circovirus type 2 infection in pigs from 1985 to 1997 in Spain. J Vet Med B Infect Dis Vet Public Health. 50:99-101, 2003

Sanchez RE Jr, Nauwynck HJ, McNeilly F, Allan GM, Pensaert MB: Porcine circovirus 2 infection in swine foetuses inoculated at different stages of gestation. Vet Microbiol. 83:169-176, 2001

Sanchez R, Nauwynck H, Pensaert M: Serological survey of porcine cirovirus 2 antibodies in domestic and feral pig populations in Belgium. Proc Conf ssDNA Viruses Plants Birds Pirmates, pp. 122. 2000

Tischer I, Glederblom H, Vettermann W, Koch MA: A very small porcine virus with circular single stranded DNA. Nature. 295:64-66, 1982

Tischer I, Mields W, Wolff D, Vagt M, Griem W: Studies on epidemiology and pathogenicity of porcine circovirus. Arch Virol. 91:271-276, 1986

Tischer I, Rasch R, Tochtermann G: Characterization of papovavirus- and picornavirus-like particles in permanent pig kidney cell lines. Zbl Bakt Hyg I Abt Orig A. 226:153-167, 1974

Walker IW, Konoby CA, Jewhurst VA, McNair I, McNeilly F, Meehan BM, Cottrell TS, Ellis JA, Allan GM: Development and application of a competitive enzyme-linked immunosorbent assay for the detection of serum antibodies to porcine circovirus type 2. J Vet Diagn Invest. 12:400-405, 2000




Biologic and Physical Properties

General Info






Molecular Organization


Host Range


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