Transmission of hepatitis C virus infection from asymptomatic mother to child in southern India.

BACKGROUND: Little information is available on the mother-to-child transmission of hepatitis C virus (HCV) in India, and no interventions to decrease transmission rates have been identified. Hence, we performed a long-term prospective study in infants born to HCV-positive mothers, with the aim of evaluating vertical transmission of HCV and correlated risks factors.

METHODS: Three thousand one hundred and fifteen healthy asymptomatic pregnant women were included in the study. We used third-generation (Murex anti-HCV) ELISA and HCV RNA reverse transcription PCR (RT-PCR) for screening, and the commercial line probe assay (Inno-LiPA) and direct sequencing HCV genotyping assays were performed to confirm the transmitted HCV genotypes.

RESULTS: Of the total 3115 healthy asymptomatic pregnant women, 18 (0.6%) were positive for anti-HCV. Of the 18 anti-HCV-positive women, eight (44.4%) were positive for HCV RNA RT-PCR. HCV transmission was observed in two of the eight babies born to eight HCV RNA-positive mothers who were followed up for 12 months. HCV genotyping of the mother/child pairs revealed the persistent presence of mixed genotypes 1a and 4 throughout the follow-up period. None of the non-viremic (HCV RNA-negative) mothers transmitted HCV infection to their baby. In our study approximately 25% of vertical/perinatal transmission of HCV was observed among HCV RNA-positive antenatal women.

CONCLUSIONS: This study is of importance as it is the first report from India of a successful attempt to analyze the rate of vertical/perinatal transmission of HCV from infected mothers to their children by a prospective longitudinal follow-up study, and to characterize the pattern of genotype(s) of HCV present in the infected mother/baby pairs, so as to confirm the source of HCV acquired by the newborn babies.