Levels of cytomegalovirus seropositivity in homosexual and heterosexual men.

The prevalence of antibodies to cytomegalovirus (CMV) among 57 homosexual men (77.2%) was significantly higher than that among 155 heterosexual men (32.3%) attending a sexually transmitted disease clinic. The difference in prevalences was most pronounced in those under 30 years of age. No difference in CMV seroprevalence was observed between the heterosexual patients and a control group of blood donors. The geometric mean titer of seropositive homosexuals (1:79) was significantly higher than that of heterosexuals (1:28) in both younger and older age groups. These data suggest that homosexual men are exposed to CMV at a much earlier age than heterosexuals and that homosexuals experience frequent reactivation or reinfection with CMV.