Characterization of porcine circovirus type 2 in Taiwan.
In an effort to understand the genetic diversity of porcine circovirus type 2 (PCV2) and the prevalence of PCV2 infection in Taiwanese herds, we have sequenced the complete genomes from PCV2-infected specimens and individually measured the antibody titer against PCV2 from pigs reared in Taiwan between the years 2000 and 2002. A total of 623 specimens originating from pigs displaying varied clinical signs were screened with the polymerase chain reaction (PCR). Results showed that 309 pigs (49.6%) tested positive for PCV2. Eight of the positive specimens were used for the amplification of the complete viral genome. Sequence comparison of the complete genomes indicated that the 8 Taiwanese PCV2 isolates shared 95-99% similarity. Phylogenetic analysis of all 40 PCV2 isolates from North America, Europe, Asia and Taiwan revealed that those isolates were grouped together in one large group containing two minor subgroups. The Taiwanese PCV2 isolates were classified into the two minor subgroups. The prevalence of serum antibodies to PCV2 in pigs was investigated, and results showed that approximately 83.5% of the pigs in Taiwan were seropositive. Finishing pigs possess the highest titers of antibodies, while 9-week-old pigs contained the lowest titers for specific antibodies. Our results suggest that PCV2 infections have become common in Taiwanese pig farms.
Wang
Chun
C
Department of Hog Cholera Research, National Institute for Animal Health, Council of Agriculture, Taipei, Taiwan.
Huang
Tien-Shine
TS
Huang
Chin-Cheng
CC
Tu
Chien
C
Jong
Ming-Hwa
MH
Lin
Shih-Yuh
SY
Lai
Shiow-Suey
SS
D000367:Age Factors; D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D001483:Base Sequence; D018173:Circoviridae Infections / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary*; D017925:Circovirus / Q000235:genetics*; D016000:Cluster Analysis; D017931:DNA Primers; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D034421:Sus scrofa; D013553:Swine Diseases / Q000453:epidemiology / Q000276:immunology / Q000821:virology*; D013624:Taiwan / Q000453:epidemiology
D000914:Antibodies, Viral; D017931:DNA Primers