AHRI report No.40

Phylogenetic analysis of classical swine fever virus isolated from Taiwan 

1.Department of Hog Cholera, National Veterinary Research Institute, Council of Agriculture

2.Graduate Institute of Veterinary Pathology, College of Veterinary Medicine, National Chung Hsing University

3.Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University

By analyzing the E2 sequences of classical swine fever virus from field outbreaks in Taiwan during 1993–2001, three virus populations with distinct genotypes were determined including one historical (subgroup 3.4) and two exotic (subgroup 2.1) strains. The first subgroup 2.1 virus was isolated in 1994 and further sporadic outbreaks occurred after 1996. Phylogenetic analysis using the E2 region has segregated the Taiwanese strains of 2.1virus into two different genotypes (termed 2.1a and 2.1b). The 2.1bviruses were onlyisolated in 2001 andshared approximately94.8%nucleotide identities to the 2.1aviruses in the total genomic sequences. The results suggest that the 2.1a and 2.1b viruses may be introduced from different origins.

Classical swine fever virus; Pestivirus; Epidemiology; Phylogenetics.