More than 20% of gay and bisexual men in Washington State considered to be at high risk for HIV infection were taking Truvada pre-exposure prophylaxis (PrEP) in 2015, and a large majority of both higher- and lower-risk men were aware of it, according to a study published in the January 28 edition of AIDS.
Daily Truvada (tenofovir/emtricitabine) PrEP has been shown to be more than 90% effective in preventing HIV infection among people who take it consistently. The US Food and Drug Administration (FDA) approved Truvada for PrEP in July 2012, but uptake was initially slow, as most people either did not know about PrEP or had concerns about its safety and efficacy. But PrEP use has accelerated in recent years in conjunction with community advocacy, especially among men who have sex with men (MSM).
Julia Hood of the Seattle and King County Public Health Department and colleagues assessed trends in PrEP awareness and use among gay and bisexual men in the US state of Washington – home to Seattle – which has the country's first PrEP drug assistance programme and a Medicaid programme that pays for PrEP.
The researchers conducted a cross-sectional survey annually at the Seattle Pride Parade between 2009 and 2015. The Gay Pride survey collects data on respondents’ demographic characteristics, access to healthcare, risk behaviours, HIV and sexually transmitted disease testing, and awareness of HIV prevention strategies and campaigns. The anonymous survey could be done by an interviewer or self-administered in English or Spanish, and respondents received condoms, information about local services and a $5 gift card.
This convenience sample included 2168 gay and bisexual men who reside in Washington State and said they had never tested HIV-positive. Most (71%) were white and the median age was 32. About half had a college education and a third reported an annual income over $50,000. The majority (70%) lived in King County, which includes Seattle, the state's largest city.
About a quarter of the men met the health department's criteria for 'high risk' for HIV infection, which included having at least ten anal sex partners, condomless anal sex with a man who was HIV-positive or of unknown status, having a bacterial sexually transmitted infection, or using methamphetamine or poppers.
Prior to FDA approval of Truvada for PrEP in 2012, only five men reported having ever used PrEP (< 1% of 2009-2011 respondents). Yet by 2015, 26 out of 115 high-risk MSM – or 23% – said they were currently taking PrEP; 72% of men who reported ever using PrEP were currently doing so.
The percentage of high-risk men who reported ever taking PrEP increased from 5% in 2012 to 31% in 2015. PrEP use among lower-risk gay and bi men remained low and stable, between 1 and 3% during the period of 2012 to 2015.
In multivariate analyses PrEP use was associated with later calendar years (adjusted relative risk 2.29) and higher HIV risk (adjusted relative risk 2.29).
The percentage of high-risk gay and bi men who had heard of PrEP increased from 13% in 2012 to 86% in 2015, while the proportion of lower-risk men who were familiar with it rose from 29 to 58%.
"PrEP awareness is high and the use has rapidly increased over the last year among MSM in Seattle, Washington, USA," the study authors concluded. "These findings demonstrate that high levels of PrEP use can be achieved among MSM at high-risk for HIV infection."
The researchers added that a number of factors distinguish the survey area from much of the rest of the US, including a relatively well-educated and affluent population, a large number of medical providers offering PrEP, the state PrEP drug assistance programme and a Medicaid programme that pays for PrEP without co-payments, and a state health department campaign to raise PrEP awareness among gay men.
However, they noted that despite the dramatic recent increase in PrEP use among high-risk MSM, only 7% of all 2015 survey respondents said they were currently taking PrEP. As a limitation of the study, they said that gay and bi men who attend Pride events may differ from MSM who do not, and the survey included a relatively small number of black and Latino men – populations disproportionately affected by HIV nationwide.
"Achieving a population-level effect on HIV transmission may require substantially higher levels of use than we observed," the researchers wrote. "At the same time, modelling studies in the USA and Australia have suggested that given current drug costs, PrEP is only cost-effective if targeted to high-risk MSM. Our findings suggest that such targeting is occurring in King County, Washington, USA."
"However, some MSM categorized as being low risk in our analysis may be at significant risk for HIV acquisition," they continued. "Future efforts should focus both on increasing PrEP uptake among high-risk MSM and developing better criteria to identify segments of the MSM population that would benefit most from PrEP."
Hood JE et al. Dramatic increase in preexposure prophylaxis use among MSM in Washington State. AIDS 30:515-519, January 28, 2016.