Of 3,816 homosexual men examined in five sexually transmitted disease clinics in the United States, 6.1% had hepatitis B surface antigen, 52.4% had antibody to hepatitis B surface antigen, and 3.0% of the men who had no other indicator of infection with hepatitis B virus (HBV) had antibody to hepatitis B core antigen. The rate of seropositivity for HBV indicated by the presence of one or more of these serologic markers was 61.5%; seropositivity was significantly related to the duration of regular homosexual activity and to the number of nonsteady male sexual contacts in the four months before the patients were interviewed. Anal-genital intercourse, oral-anal intercourse, and rectal douching were significantly related to evidence of HBV infection, but oral-oral contact and oral-genital contact were not. Trauma to the rectal mucosa is a feature common to the practices that were significantly related to seropositivity for HBV.

To estimate the risk of hepatitis B virus (HBV) infection among hospital workers, we measured the prevalence of HBV infection in employees in five hospitals in different parts of the country and examined the effect of occupational and non-occupational factors on HBV prevalence. Among 5,697 persons studied, serologic markers of HBV infection were found in 807 (14%). Prevalence of infection was strongly related to race (Asian > Black > White), sex (male > female) and increasing age.Risk related to health occupation, studied by examining the change in HBV prevalence with duration in occupational group, was most strongly correlated with frequency of contact with blood during work. Workers having frequent blood contact had the highest estimated infection rate (1.05 per 100 person-years) and those with moderate contact an intermediate infection rate, compared to a negligible infection rate in workers with no blood contact. Frequency of needle accidents had an independent, positive effect on HBV infection rates, while degree of patient contact had no effect. Infection risk was uniform among all hospitals for groups with frequent blood contact. Among different occupation groups, risk of HBV infection also correlated closely with degree of blood-needle contact during daily work. This study provides a general approach to assessing risk of HBV infection in hospital personnel, and indicates that risk may be most easily estimated by quantitating degree of blood-needle contact during daily work.