Background: Interspousal transmission of hepatitis C virus (HCV) has been documented; however, the annual risk of interspousal transmission remains unclear.
Methods: A long-term prospective study to define the risk of interspousal transmission of HCV was conducted. One hundred and twelve index patients with chronic hepatitis C and their anti-HCV seronegative spouses were enrolled.
Results: The mean follow-up period was 45.9 months. Antibodies to HCV (anti-HCV) and HCV-RNA were tested for in each seronegative spouse every year. Seroconversion of anti-HCV occurred in only one spouse, 2 years after enrolment, with a concomitant acute hepatitis. This subject and his spouse were infected with HCV genotype 1b. Nucleotide sequence comparison of the hypervariable region of their HCV genomes showed a homology of 98%. Further phylogenetic analysis suggested that they had virtually the same isolate. Accordingly, the annual risk of interspousal transmission of HCV infection was 0.23% per year.
Conclusions: These findings suggest a low incidence of interspousal transmission of HCV; however, the risk may be cumulative and such couples should be educated to avoid HCV infection from their spouses.