Sero-epidemiologic study to determine the prevalence and risk of hepatitis B in a Canadian heterosexual sexually transmitted disease population.

This prospective study was carried out to determine the seroprevalence and to examine the sexual determinants of hepatitis B virus in a Sexually Transmitted Disease (STD) Clinic population. 217 men and 81 women were entered. The overall prevalence of hepatitis B markers was 7.7%. Women with more than ten lifetime sexual partners were twice as likely to have been exposed to hepatitis B (OR 1.9). Both men and women who had been sexually active for more than seven years were two to three times as likely to have been in contact with hepatitis B (OR 2.2 (men), 3.1 (women)). Injection drug use was also associated with hepatitis B infection (OR 4.69). There was no association between hepatitis B infection and type of sexual contact. The presence of an STD was associated with an increased prevalence of hepatitis B virus infection. This population should be considered for hepatitis B vaccination.