Epidemiology of sexually transmitted hepatitis B infections in heterosexuals: a review.

The evidence that hepatitis B virus is transmitted between heterosexuals as a result of sexual contact is indirect, incomplete, and depends on definitions. In developed western countries, the highest attack rate for endemic hepatitis B is found in sexually active young adults. Compared to the prevalence among "controls," the prevalences of hepatitis B surface antigen (HBsAg) and/or its antibody are significantly higher in female prostitutes, in women with venereal diseases, and in spouses of patients with hepatitis B. Prospective studies of serosusceptible spouse contacts of persons infected with hepatitis B virus have established secondary attack rates of 20-27%. No study has determined what types of heterosexual contact lead to infection or the risk of infection from a single sexual encounter. The highest concentration of HBsAg is found in blood, but HBsAg also appears in saliva, semen, menstrual discharge, vaginal secretions, feces, urine, and tears. Although HBsAg-positive blood transmits infection to humans when given by mouth and injections of HBsAg-positive human saliva will transmit hepatitis B virus to gibbons or chimpanzees, the epidemiologic importance of saliva and other secretions and excretions in transmitting hepatitis B virus during sexual contact is unknown. Hepatitis B vaccine may be indicated for preexposure prophylaxis of serosusceptible heterosexuals at high risk hepatitis B.