Abstract: | An infant born prematurely and infected with hepatitis C virus (HCV) one month after birth was followed for 4.5 years. The patient did not produce detectable anti-HCV antibodies until two years after the onset of hepatitis. Before seroconversion, a single clone of HCV, as determined by quasispecies of the hypervariable region (HVR) of the HCV genome, was almost exclusively found in the serum. After seroconversion, however, another distinct lineage of HCV clones replaced it within half a year. As HCV infection persisted further in the presence of anti-HCV antibodies, many derivatives of both sequence lineages emerged to exhibit the typical quasispecies feature of HVR sequences. Neither seroconversion nor the changes in HVR sequences influenced the serum aminotransferase titers. |