Background:  Although guidelines exist for non-occupational post-exposure prophylaxis (PEP) to prevent HIV infection, the safety and efficacy of pre-exposure prophylaxis (PrEP) are unknown. Media reports and sparse data suggest that some men who have sex with men (MSM) may already be using PrEP. In 2004, the Centers for Disease Control and Prevention (CDC) used self-administered questionnaires to survey a convenience sample of MSM at minority gay pride events:  25% of MSM reported that they had heard of PrEP, and 5% reported that they had used PrEP. The extent to which HIV⁺ persons may share ART with HIV^– sex partners is unknown.

Methods:  In collaboration with community-based organizations and state and local health departments, we conducted surveys at minority gay pride events in 2005 (Detroit, Michigan; Jackson, Mississippi; San Francisco, California; Washington, DC) and 2006 (Chicago, Illinois; Charlotte, North Carolina; St Louis, Missouri). We selected respondents by using systematic sampling. We collected demographic and behavioral data and assessed knowledge and use of PrEP and PEP to prevent HIV. Specifically, respondents were asked whether they had ever heard of people who take ART to keep from getting HIV and whether they had ever used ART just before (PrEP) or after (PEP) engaging in a risky activity. HIV⁺ respondents were asked whether they had ever given ART to an HIV^– sex partner to keep the partner from getting HIV. Data were collected by using a hand-held computer to conduct in-person interviews.

Results:  The analysis included 468 MSM. Respondents’ median age was 32 years (range 18 to 66 years), 363 (77.6%) were non-Hispanic blacks, and 68 (14.5%) identified themselves as HIV⁺. Of the 400 respondents who did not report being HIV⁺, 1 (0.3%) reported PrEP use, and 7 (1.8%) reported PEP use. Of all 468 respondents, 102 (21.8%) had heard of the use of ARV to prevent HIV. Knowledge of prophylactic use of ART was significantly associated with HIV⁺ sero-status (OR 2.4, 95%CI 1.4 to 4.2) and having ≥10 male anal sex partners vs 1 anal sex partner during the past year (OR 2.5, 95%CI 1.3 to 5.1). No HIV⁺ respondents reported providing ART to HIV^– sex partners.

Conclusions:  In contrast to the results of the 2004 CDC surveys, the use of ART to prevent HIV was low among men surveyed at minority gay pride events during 2005-2006. Different methods used in the more recent surveys (eg, systematic sampling and in-person interviews) may account for the different results.