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PrEP use is skyrocketing among people at the highest risk of contracting HIV: In a presentation at the 22nd International AIDS Conference in Amsterdam, researchers from the CDC and Emory University’s Rollins School of Public Health revealed that, within the at-risk demographic, the rate of PrEP use went from 7.0 per 1,000 in 2012 to to 68.5 per 1,000 in 2016.
In that same five-year timeframe, new HIV diagnoses decreased in the general population from 15.7 per 100,000 persons to 14.5. States with the highest utilization of Truvada, the anti-HIV therapy’s commercial name, saw the greatest declines in HIV rates, while those with the lowest PrEP rates, on average, saw an increase in new HIV diagnoses.
Even controlling for those variables, though, data from the National HIV Surveillance System showed PrEP use was still associated with serious declines in new HIV diagnoses.
“These data further validate the potential for significant public health impacts of Truvada for PrEP to help reduce HIV transmission in the U.S.,” says lead author Patrick Sullivan. “By documenting significant declines in average new cases of HIV in states where Truvada for PrEP has been most widely adopted, our analysis emphasizes the importance of improving access to HIV screening and a full range of prevention tools, including PrEP, in U.S. states.”
That increase is also having an unintended consequence: a reduction in condom usage among gay and bisexual men.
Using data from the Melbourne and Sydney Gay Community Periodic Surveys (GCPS), scientists at the University of New South Wales found that in 2013, 1% of the 2,692 men who reported condomless anal intercourse with casual partners (CAIC) were HIV-negative and used PrEP.
According to a study published last month in The Lancet, that percentage rose to 5% of 3,660 men in 2016 and 16% of 4,018 men in 2017.
Consistent condom use was reported by 46% of men in 2013, 42% in 2015 and just 31% in 2017, while the rate of men who were HIV-negative or untested and not on PrEP remained fairly consistent. The Australian government approved PrEP in May 2016 — previously access was limited to clinical trials and people who purchased Truvada overseas or were willing to buy it on the black market.
A different presentation at this year’s International AIDS Conference suggested PrEP might be less effective in trans women taking female hormones. Dr. Akarin Hiransuthikul of the Thai Red Cross AIDS Researcher Centre said that, after eight weeks, trans women who combined the two therapies showed a 13% decrease in tenofovir, one of the two ingredients that comprises PrEP.
Previous reports had already pointed to lower blood levels of PrEP in transgender women, but researchers weren’t sure if that was due to drug interaction, noncompliance with PrEP or some other factor. To find the answer, Hiransuthikul adjusted the dosage of both female hormones and PrEP among 20 transgender volunteers.
“This is a small study but it is important to the trans community who have real questions about this,” Linda-Gail Bekker of the International AIDS Society told MedPage Today. “It is important that the trans community knows we are doing research in this area.”
Hiransuthikul said there are still important issues to address before making any determinations. “Does this interaction occur in target tissues such as those in the rectum? And does this reduction in blood concentration of tenofovir mean anything clinically to the effectiveness of PrEP?”
Hiransuthikul added that PrEp use had no real effect on the levels of estrogen medication in their volunteers.