Serotypes, genotypes and levels of hepatitis C viremia in pregnant women in Taiwan

The correlation between a new serotyping method for grouping different genotypes of hepatitis C virus (HCV)) and those identified by a polymerase chain reaction (PCR) assay with type-specific primers was investigated in 3,400 pregnant women. The correlation between HCV genotypes and serum HCV levels in HCV-positive pregnant women was studied as well. The new serologic assay used an enzyme-linked immunosorbent assay (ELISA) based on highly group-specific recombinant peptides (Cl4-1 and Cl4-2) within the NS4 region and deterred group-specific antibodies against different HCV genotypes. Serum HCV levels were assayed by a competitive PCR method. In all, 43 pregnant women were found to be positive for HCN antibodies by the second-generation ELISA method and were positive for HCV-RNA by PCR with primers from the 5' untranslated region. All 43 had defined genotypes: 28 (65%) with HCV 1b, 11 (26%) HCV 2a, 3 (7%) HCV 2b and 1 (2%) HCV1b + 2a. In 40 (93%) of the 43 viremic pregnant women, the results of serotyping by ELISA showed complete agreement with those determined by PCR genotyping, and none of the women showed a group different from that of the HCV genotype. In addition, serum levels of HCV Ib were significantly higher than those of HCV 2a. The results show that this new serotyping assay is highly sensitive and specific for the determination of HCV genotypes and that serum HCV levels in pregnant women with genotype Ib are higher than those with genotype 2a.