The San Francisco AIDS Foundation’s Truvada (tenofovir/emtricitabine) as pre-exposure prophylaxis (PrEP) program has not seen any participants contract HIV, even as high proportions of those who have thus far made later clinic visits reported more recent condomless sex, the National AIDS Treatment Advocacy Project (NATAP) reports. By comparison, 82 individuals at the foundation’s clinic, called Strut, have tested positive for the virus during the same two-year period.
Investigators analyzed data from Strut and presented their findings at the 21st International AIDS Conference in Durban, South Africa (AIDS 2016).
The clinic has screened 1,252 individuals since 2014 and enrolled 95.5 percent of them in the PrEP program. All participants were cisgender men who have sex with men (MSM) with the exception of three who were transgender men. On average, the men were 35 years old; the youngest was 18 and the oldest 72.
Broken down by race, the participants were 55 percent white, 25 percent Latino, 12 percent Asian, 4 percent black and 3 percent mixed race. Blacks make up 6 percent of San Francisco residents, while 17 percent of local new HIV infections were among blacks in 2015.
At enrollment, the participants reported an average of 17.4 sex partners during the previous year and a median of 10 partners. A total of 92.7 percent reported having condomless sex as the reason for wanting PrEP; 3.8 percent said being in a monogamous relationship with an HIV-positive partner was the reason; 3.6 percent reported consistent condom use.
Participants in the Strut PrEP program are seen one month after receiving a Truvada prescription and every three months thereafter. Data about the series of clinic visits are cross-sectional, meaning that any findings about the visits apply only to the group of people who kept each particular appointment in the series. Some participants might have dropped out of the program and others have been in it only a short while. This means the proportions of various outcomes identified at each visit are not necessarily comparable to one another, since they are not necessarily derived from the same group of people.
If attendance had been perfect, a respective 1,144 people, 692 people, 433 people, 260 people, 102 people and 25 people would have made the 1-, 4-, 7-, 10-, 13- and 16-month visits. The proportion of those sets of people that did make each visit was a respective 80.5 percent, 79.3 percent, 78.5 percent, 76.9 percent, 88.2 percent and 84 percent.
The respective proportions of those making each study visit who reported taking four or more doses of Truvada during the previous week (which research has shown offers maximum protection against HIV) were 95.1 percent, 91.3 percent, 90.3 percent, 91 percent, 92.2 percent and 100 percent.
The proportion of participants diagnosed with sexually transmitted infections at each visit was largely between 10 and 20 percent. However, the proportion of participants reporting a recent increase in the amount of condomless sex was higher among those attending the later visits. The proportion of those at the 1-, 4-, 7-, 10-, 13- and 16-month visits reporting “about the same amount” of recent condomless sex was a respective 61.3 percent, 51.9 percent, 52.9 percent, 46 percent, 48.9 percent and 38.1 percent. Meanwhile, the respective proportion at each visit that reported having more condomless sex recently was 16.4 percent, 30.1 percent, 34.1 percent, 39 percent, 37.8 percent and 47.6 percent. Again since these figures are not reflective of the same group of people over time, direct comparisons cannot be made.
No one enrolled in the program has tested positive for HIV. This is compared with 82 new infections seen in attendees of the Strut clinic who are not enrolled in the PrEP program during the same period.
To read the NATAP report, click here.