The study followed over 600 people, of which 99% were gay men or men who have sex with men, as they used the drug Truvada daily for 32 months. The researchers found that none of the participants became infected with HIV during this period.
Lead author Jonathan Volk, physician and epidemiologist at Kaiser Permanente San Francisco Medical Center, said that, “until now, evidence supporting the efficacy of PrEP to prevent HIV infection had come from clinical trials and a demonstration project.”
He explained that, “Our study is the first to extend the understanding of the use of PrEP in a real-world setting and suggests that the treatment may prevent new HIV infections even in a high-risk setting.”
While PrEP may have protected these men from HIV, it has no effect on other sexually transmitted infections (STIs), which is why condom use is still recommended.
In fact, six months after initiation, 30 percent of the PrEP users had been diagnosed with at least one STI. At 12 months, 50 percent of PrEP users had been diagnosed with an STI; 33 percent had a rectal STI, 33 percent had chlamydia, 28 percent had gonorrhoea, and 5.5 percent had syphilis.
“Without a control group, we don’t know if these STI rates were higher than what we would have seen without PrEP,” commented co-author Julia Marcus, postdoctoral fellow at the Kaiser Permanente Division of Research. “Ongoing screening and treatments for STIs, including hepatitis C, are an essential component of a PrEP treatment program,” she added.
PrEP use by gay, bisexual and other men who have sex with men, especially those at high risk, has been endorsed by America’s Centres for Disease Control and Prevention (CDC) and the World Health Organisation (WHO).
PrEP is not currently offered in public hospitals and clinics in South Africa, although those who can afford to pay for it may request a prescription from a private doctor or a gay-friendly clinic, such as OUT in Pretoria. The use of PrEP will require regular monitoring.
The new study was published in the journal Clinical Infectious Diseases.