Following the 2017 revision of guidelines indicating who most stands to benefit from taking pre-exposure prophylaxis (PrEP), researchers surveyed men who have sex with men (MSM) and found that a greater proportion of them may be good PrEP candidates than previous research suggested.

In 2017, a Centers for Disease Control and Prevention (CDC) analysis estimated that 24.7% of sexually active HIV-negative MSM were good PrEP candidates, according to the 2014 U.S. Public Health Service (USPHS) clinical practice guidelines. These guidelines were revised in 2017.

The original guidelines indicated that gay and bisexual men and other MSM were good PrEP candidates if they had: reported condomless intercourse during the prior six months; been diagnosed with any sexually transmitted infection (STI) during the previous six months; or were in an ongoing relationship with an HIV-positive partner.

The 2017 revision specified that the STI diagnosis must have been for a bacterial infection, including gonorrhea, chlamydia or syphilis. The revision also struck the criterion about having an HIV-positive partner, acknowledging research indicating that people with an undetectable viral load cannot transmit the virus.

Publishing their findings in the Journal of Acquired Immune Deficiency Syndromes, researchers behind the new study conducted a national web-based survey between July 2017 and January 2019 among 4,904 MSM 15 to 65 years old.

Out of 3,511 sexually active HIV-negative men who responded to the survey, 34.0% met the USPHS indications for PrEP. This figure was consistent across the main regions of the United States and varied only slightly according to race and ethnicity.

Among those who made good PrEP candidates, 93.5% reported engaging in condomless intercourse during the previous six months.

“Estimated percentages of MSM meeting indications for PrEP exceeded the previous CDC estimate across race/ethnicity, age, and census regions, with one third of adult, sexually active HIV-negative MSM exhibiting indications for PrEP,” the study authors concluded. “This study suggests, given current guidelines for PrEP indications, that a different fraction of eligible MSM could be receiving PrEP than previously estimated.”

This study is limited by the fact that it was based on a survey that did not yield a representative sample of the MSM population, as did the previous CDC study. So the new study’s findings may not be generalizable to all MSM.

To read the study, click here.