Evaluation of sexual transmission in patients with chronic hepatitis C infection.

BACKGROUND: The transmission of hepatitis C virus (HCV) by parenteral exposure is well documented. However, a proportion of patients with acute or chronic HCV infection have an unknown source of infection.

OBJECTIVES: The purpose of this study is to evaluate the role of sexual transmission in HCV infection.

STUDY DESIGN: 68 patients (median age, 50 years) with chronic hepatitis C and their spouses were tested for the presence of antibody to HCV (anti-HCV) by multi-antigen and chimeric C25 antigen enzyme immunoassays and for HCV RNA by the polymerase chain reaction. Information on sexual activity and risk factors for HCV infection were obtained from all couples via a questionnaire.

RESULTS: All index patients were positive for both anti-HCV and HCV RNA. Antibody to HCV was detected in four (5.9%) of their spouses. One anti-HCV-positive spouse had a history of blood transfusion while the other three (4.4%, 95% CI = 1.5-12.2%) had no known risk factors for HCV infection and thus may have been exposed to HCV via sexual transmission. Two of these 3 spouses had positive serum HCV RNA and had identical HCV genotype to the index patients. The length of sexual exposure was significantly longer in the couples who both were anti-HCV-positive than in patients whose spouses were anti-HCV negative (median: 25 vs. 10 years, P = 0.02, Mann-Whitney test). In our 68 index patients, 96% had antibodies to the recombinant proteins from the C22 (core) and C33C (NS3) regions, and 82% and 76% had antibodies to the proteins from the NS5 and C100-3 (NS4) regions. Identical anti-HCV profiles were noted in two of the four anti-HCV-positive couples.

CONCLUSIONS: Our results indicate that sexual transmission, although uncommon, should be considered as a risk factor for HCV infection, especially in spouses who have had long-term intimate relationships with a chronic hepatitis C patient.