A case of acute hepatitis C caused by interspousal transmission after 30 years of marriage.

We describe a case of interspousal transmission of hepatitis C virus (HCV) infection after 30 years of marriage which was confirmed by gene analysis. A 60-year-old man was referred to our hospital because of severe hepatic dysfunction. Laboratory findings showed that HCV-Ab titer and qualitative Amplicor HCV were both positive in low levels. Because the patient regularly consumes various health foods, it was initially difficult to rule out drug-induced hepatopathy, but the patient was diagnosed with acute hepatitis C when HCV antibody titer increased 4 months later. Because his wife also tested positive for HCV antibody, interspousal transmission was suspected, and gene analysis was performed. Both husband and wife had HCV 1b, and the base sequence homology of 1087 base pairs (bp) in the NS5B region was 98.6% (99.4% at the amino acid level). In addition, upon analysis of the E1 and E2 junctional region sequence (268 bp) including hypervariable region 1 (HVR-1), a close relationship (89.2-99.6%) between clones obtained from each spouse was observed, thus confirming that the source of infection was his wife. Thorough medical history taking suggested that sexual intercourse was the most likely route of infection. In previous large-scale clinical studies, the frequency of HCV infection between married couples has been extremely low, but it is important to obtain informed consent regarding the potential risk of infection.