By Lisa Rapaport

(Reuters Health) – A growing proportion of American men who have sex with men know they can take a daily pill to avoid infection with HIV and more of them are using it, a U.S. study suggests.

So-called HIV pre-exposure prophylaxis (PrEP) is highly protective against the virus that causes AIDS, but many people worldwide don’t get this pill because they aren’t aware of it, don’t think they need it, or because it’s unavailable or unaffordable. Efforts to raise awareness among one high-risk group – men who have sex with men – have been complicated because some of these men don’t identify as gay or bisexual and mistakenly think heterosexual people don’t need PrEP.

In 2014, the U.S. Centers for Disease Control and Prevention (CDC) launched an effort to get PrEP to all men who have sex with men who might benefit from the pill, not just gay and bisexual individuals. The current study looked at national health survey data to track changes in awareness and use of PrEP from 2014 to 2017 in 20 American cities.

Overall, there was “a significant increase in the percentage of gay and bisexual men at high risk for HIV who are using PrEP,” said Teresa Finlayson, lead author of the study and a researcher at the CDC in Atlanta.

By 2017, the percentage of at-risk men who have sex with men who were aware of PrEP had risen from 60% to 90%. And 35% of these men were using PrEP by 2017, up from 6% in 2014.

“Although PrEP use has increased, PrEP use remains too low, particularly among gay and bisexual African American and Latino men,” Finlayson said by email.

Among black men in the study, awareness of PrEP rose from 47% to 86%, while use of the pill climbed from 4% to 26%.

For Hispanic or Latino men, awareness of PrEP increased from 49% to 87%, while use rose from 4% to 30%

White men fared better, with awareness of PrEP growing from 72% to 95% and use increasing from 8% to 42%.

Men who identified as heterosexual were less aware of PrEP and less likely to use the daily pill by the end of the study than men who identified as gay or bisexual, researchers report in the CDC’s Morbidity and Mortality Weekly Report.

One limitation of the study is the potential that men didn’t accurately report their awareness or use of PrEP in the surveys.

A potential drawback of increased PrEP use is that it might lead to a decline in condom use and a rise in other sexually transmitted infections, some previous research suggests.

One recent study compared rates of three sexually transmitted infections – syphilis, gonorrhea and chlamydia – before and after PrEP became a standard of care.

Compared to the pre-PrEP period, syphilis infection rates rose 25% in the post-PrEP period and gonorrhea rates rose 26%. Chlamydia rates fell 12%.

Still, the current study results show that many people who need PrEP may mistakenly think they don’t, said Aaron Siegler, a health education researcher at Emory University who wasn’t involved in the study.

“Guidance regarding persons that should be on PrEP has remained consistent from CDC, but misperceptions in what makes a person eligible for PrEP are rampant,” Siegler said by email.

In surveys of black men who have sex with men, for example, Siegler and colleagues found one participant who articulated a common reason people don’t take the pill. This man said, “PrEP is for people… having sex like bunnies,'” Siegler noted.

“In fact, PrEP can be right for a person who has just one sexual partner but does not know the HIV status of their partner or is unable to use condoms each and every time,” Siegler said.

SOURCE: CDC Morbidity and Mortality Weekly Report, online July 12, 2019.