Distribution of hepatitis C virus genotypes among blood donors in Taiwan.

The aim of this study was to investigate the prevalence and distribution of hepatitis C virus (HCV) genotypes of blood donors in Taiwan. RNA was extracted from the serum of anti-hepatitis C virus-positive carriers and this was followed by reverse transcriptase-polymerase chain reaction (RT-PCR) using type-specific primers for the presence of HCV genotypes, 1a, 1b, 2a, 2b, 3a and 6a. Of the 604 anti-HCV-positive specimens, the PCR demonstrated that 93.0% (562/604) were positive for at least one HCV genotype. The remaining 42 specimens (7%) were HCV negative. Among the 562 HCV-positive specimens, 505 (89.8%) contained HCV 1a, 1b, 2a, 2b and 3a as the only genotype, with a prevalence of 0.4% (2/562), 60.1% (338/562), 15.5% (87/562), 11.9% (67/562), and 2.0% (11/562), respectively. No HCV genotype 6a was found. Thirty-seven specimens (6.6%) exhibited mixed infections with multiple HCV genotypes that included types 1b, 2a and 2b, while 20 (3.5%) HCV RNA-positive sera remained unclassified. These results confirm that the predominant HCV genotype in Taiwan is 1b. In addition, genotypes 1a and 3a can also be found in Taiwan at low frequency.