Low prevalence of HIV in high-risk seronegative homosexual men evidenced by virus culture and polymerase chain reaction.
OBJECTIVE: To assess the presence of covert HIV-1 infection. SETTING: High-risk seronegative homosexual men from the Pittsburgh portion of the Multicenter AIDS Cohort Study were examined for the presence of HIV-1 infection. PATIENTS, PARTICIPANTS: Ten men (group 1) were examined prospectively for the presence of HIV-1 in their freshly-obtained peripheral blood mononuclear cells (PBMC). Furthermore, cryopreserved PBMC from 26 men (group 2) at their first visit (1984-1985) were examined retrospectively for the presence of HIV-1. MAIN OUTCOME MEASURES: PBMC samples from groups 1 and 2 were examined for HIV-1 by polymerase chain reaction (PCR) using gag, env and strong-stop (long terminal repeat) specific primers. In addition, fresh PBMC samples from group 1 were examined for HIV-1 by virus culture. RESULTS: None of the 10 PBMC samples from group 1 were positive for virus culture and PCR. Only one of the 26 men from group 2 was positive for gag and strong-stop DNA sequences. This PCR-positive, seronegative subject was found to be negative for HIV-1 by PCR at follow-up visits up to 48 months later. None of 15 seronegative, low-risk homosexual men and 12 seronegative heterosexual men were found to be PCR-positive for HIV-1. However, six HIV-1-seropositive men were positive by PCR for gag, env, and strong-stop HIV-1 DNA sequences. CONCLUSIONS: These results suggest a low prevalence of covert HIV-1 infection in high-risk seronegative homosexual men in our geographic area.