Awareness and use of HIV pre-exposure prophylaxis (PrEP) are found to be low in San Francisco gay and bisexual men

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Over the past two years, the media has shown a keen interest in reporting on HIV pre-exposure prophylaxis (PrEP) animal studies presented at AIDS conferences

and in the highly controversial PrEP safety trial conducted amongst African female sex workers . In turn, some speculate that there is a heightened awareness of PrEP as a possible new HIV prevention strategy in gay men and that a significant number are actively using it as an “evening-before pill” prior to engaging in risky sexual behavior.

This speculation was given credence last summer when Scott Kellerman and colleagues from the US CDC presented data at the Third International AIDS Society Conference on HIV Pathogenesis and Treatment in Rio de Janeiro, Brazil, detailing heightened awareness and use of PrEP in urban gay men of color. In the subgroup of men from San Francisco, 29% and 9%, reported awareness and use of PrEP, respectively.


post-exposure prophylaxis (PEP)

A month-long course of antiretroviral medicines taken after exposure or possible exposure to HIV, to reduce the risk of acquiring HIV.

unprotected anal intercourse (UAI)

In relation to sex, a term previously used to describe sex without condoms. However, we now know that protection from HIV can be achieved by taking PrEP or the HIV-positive partner having an undetectable viral load, without condoms being required. The term has fallen out of favour due to its ambiguity.


Studies aim to give information that will be applicable to a large group of people (e.g. adults with diagnosed HIV in the UK). Because it is impractical to conduct a study with such a large group, only a sub-group (a sample) takes part in a study. This isn’t a problem as long as the characteristics of the sample are similar to those of the wider group (e.g. in terms of age, gender, CD4 count and years since diagnosis).

sexually transmitted diseases (STDs)

Although HIV can be sexually transmitted, the term is most often used to refer to chlamydia, gonorrhoea, syphilis, herpes, scabies, trichomonas vaginalis, etc.


The presence or absence of detectable antibodies against an infectious agent, such as HIV, in the blood. Often used as a synonym for HIV status: seronegative or seropositive.

Findings from a study presented last week by Liu and colleagues from the San Francisco Department of Public Health and the University of California, San Francisco at the Sixteenth International AIDS Conference in Toronto seriously call into question this robust awareness and use of PrEP in gay men. A cross-sectional survey of PrEP awareness and knowledge was administered to 851 gay or bisexual men who self-reported having a negative or unknown HIV serostatus. These men were sampled from three different subgroups: 403 men were randomly sampled from San Francisco gay venues; 176 were attendees of a circuit party in Palm Springs; and the third group consisted of 272 men attending the San Francisco STD (sexually transmitted diseases) clinic. Approximately 40% were men of colour; close to 50% were college-educated and about 30% earned $60,000 a year or more. The circuit party sample had significantly more college-educated men and a higher yearly income compared to the San Francisco and sexual health clinic groups. There was a substantial amount of recreation drug use reported in San Francisco and circuit party groups, and 37% and 51%, respectively, reported unprotected anal intercourse.

Overall, 18% of the men had heard of PrEP: San Francisco = 20%; circuit party = 19%: sexual health clinic = 15%. Unprotected anal intercourse in the last six months was the only variable significantly associated with PrEP awareness (adjusted OR: 2.0 [95% CI: 1.3, 3.0]). Newspapers and magazines were overwhelmingly noted as the top source of PrEP knowledge, followed by conversations with friends.

Reports of PrEP use in the entire sample were basically non-existent; only one patient from the sexual health clinic claimed prior use (overall 0.12%). Investigators question the veracity of the patient’s claim because upon further questioning, he reported being administered 30 days of antiretroviral medication from his doctor, and thus probably confused PrEP with post-exposure prophylaxis (PEP).

Importantly, 68% overall said they would take PrEP medication daily if it was found to be safe and effective in preventing HIV transmission. In the multivariate model, independent correlates of anticipated future PrEP use were significant for: 1) men of color; 2) those reporting unprecedented anal intercourse; 3) men noting recreational drug use.

According to Liu, “contrary to prior reports, PrEP use appears to be rare in three different samples of gay and bisexual men.” He did say that because PrEP awareness and anticipated future PrEP use were associated with high risk behaviors, “PrEP use in the future would need to be integrated into existing prevention strategies and would not be a replacement for these measures.” Liu concluded with a call for more “responsible media reporting” because it was the main source of PrEP knowledge in the survey, and that how PrEP is portrayed in the media “could potentially influence how it is used in the community in advance of definitive efficacy data.”


Kellerman S, et al. Knowledge and use of pre-exposure prophylaxis among attendees of minority gay pride events, 2004. Third International AIDS Society Conference on HIV Pathogenesis and Treatment, Rio de Janeiro, abstract WePe10.3P03, 2005.

Liu A et al. Low levels of pre-exposure prophylaxis awareness and use among HIV-negative/unknown gay/bisexual men: San Francisco Bay Area residents, circuit party attendees, and clients of an urban STD clinic. Sixteenth International AIDS Conference, Toronto, abstract THLB0101, 2006.