Virus isolation and immune studies in a cohort of homosexual men

Virus shedding was detected in 77% of homosexual subjects and in only 6% of heterosexual controls. The overall virus isolation rate in homosexual subjects was not significantly different among HIV-seropositive (79%) and HIV-seronegative (74%) individuals. In about 20% of homosexual subjects, virus shedding from multiple sites was observed. The most frequently isolated virus was cytomegalovirus (CMV) (41%), followed by enteroviruses (23%), herpes simplex virus (HSV) (7%), and adenoviruses (6%). In the control group, about 50% of subjects were seronegative for HSV-1 and 2, and about 70% were negative for CMV and Epstein-Barr virus (EBV). Only 2% of homosexuals were seronegative for CMV, about 5% for HSV-1 and 2, and about 20% for EBV. No differences were found in antibody levels against varicella-zoster virus (VZV) among the control and homosexual groups. The proportion of seronegatives for Coxsackie and hepatitis viruses was significantly higher in control than in homosexual subjects. However, no differences in the proportion of seronegatives for measles, mumps, and rubella were observed. No HIV-antibody-negative individual was detected with an OKT4/OKT8 ratio of less than 0.75. On the other hand, only HIV-positive subjects, with a ratio of less than 0.75, had high serum IFN alpha titers. The results suggest that the high rate of virus shedding among HIV-negative homosexual subjects might be a factor in the development of AIDS in this high-risk population.