A 32-month study at the Kaiser Permanente San Francisco Medical Center found that among sexually active gay men who were taking PrEP (pre-exposure prophylaxis) — the HIV-prevention treatment program using the drug Truvada — no new HIV infections were reported. This is the first "real-world" study of the drug, after clinical trials convinced the FDA and CDC to recommend its use in preventing HIV infection among at-risk individuals, such as those who are HIV-negative with HIV-positive sexual partners.

The study results were published in the journal Clinical Infectious Diseases.

As the Chronicle reports, the study followed 657 people, 99 percent of whom were men who have sex with men, with an average age of 37. All of the participants considered themselves sexually active, and not all used condoms.

The average length of Truvada use in the study was seven and a half months.

Critics of PrEP have cited the fact that other sexually transmitted diseases would be likely to rise among those taking the drug and eschewing the use of condoms, and the study found that yes, there was a 30-percent instance of other STDs within six months, and that went up to 50 percent after a year. However, HIV was not among those STDs.

As study co-author Julia Marcus tells HIVPlusMag, “Without a control group, we don’t know if these STI rates were higher than what we would have seen without PrEP. Ongoing screening and treatments for STIs, including hepatitis C, are an essential component of a PrEP treatment program."

Behavior, it seems, was not drastically different among those newly taking the dug, however condom use did go down. 74 percent of participants said there was no change in the number of sexual partners they had while taking the drug, and only 11 percent said they had more sexual partners. Also, 41 percent said they decreased their use of condoms, while 51 percent said their condom use was unchanged.

The initial clinical study of the drug happened here in SF as well, and this short film from 2014 was meant to highlight its effectiveness as an HIV prevention strategy for anyone who wanted to take it. UCSF medical professor Robert Grant, who took part in the first trial, compared its use and the stigma around it to the early years of the birth control pill, saying, "It takes a while for people to get used to new ideas, especially when it relates to sexuality."

Last year, openly gay Supervisor Scott Wiener came out as a PrEP user, and Supervisor David Campos subsequently pushed for greater access to the drug among low-income people.

Previously: More HIV-Negative Gay Men Should Consider Taking Truvada, Say SF Porn Stars