Hong-Ha Troung, presented more data from San Francisco characterising new HIV infections. STIs remain a significant cofactor in new infections and 57% of recent infections are related to clusters. The definition of cluster was quite restrictive and did not include sequential infections so perhaps underestimates related infections. Important for the Australian setting was the very strong take home message that STI testing, treatment and prevention messages must become decoupled from HIV prevention activities. Abstract #37
Alison Rodgers presented data from UCL on condomless sex. This work goes to the heart of what we are seeking which is greater understanding of the extent of the prevention benefit of treatment. The data looked impressive with no transmissions reported, in any of the arms where partners had a VL <200 copies. But Rodgers was eager to point out that the confidence levels meant that this did not translate to 100% protection and that this was particularly the case with the MSM group. A factor which makes answering this question difficult is that most studies are looking at condom use AND treatment. So it was useful to see an analysis of condomless sex. Abstract #153LB
The importance of adherence to PrEP was highlighted by a number of speakers throughout the day. A number of speakers in the Prevention and Epidemiology session Evolving Trends (Session O-3) made reference to poor performance being a result of lack of adherence rather than failure of prophylaxis. And many speakers reflected on this emphasising the need for a good understanding of the social and other pressures on study participants.
PrEP is getting attention from both developing and developed country settings. It is sobering that so few studies are actually underway. Nelly Mugo, Abstract #62, found that only 1 of 10 studies had actually started, yet drugs for use as PrEP have been licensed for a considerable time.