This IAS 2017 session was dedicated to addressing HIV in 4 main populations that have been identified as “key” around the world, including migrants, sex workers, men who have sex with men and people who inject drugs. The studies presented had varied countries of origin which helped to demonstrate that key populations vary worldwide.
The first presentation presented data from the aMASE study to determine the rate of migrant acquisition of HIV in Spain. This was a multi-centre cross sectional study that collected data from both patient questionnaires and clinical notes in 6 regions around Spain of patients who had been diagnosed with HIV in the preceding five years and had lived in Spain for a minimum of six months at time of diagnosis. A range of information was collected including socioeconomic, behavioural, migratory, previous HIV testing, CD4 and viral load levels and resulted in a statistical analysis to determine most likely time and place of acquisition.
Of 710 participants, there was sufficient data to estimate time of acquisition for 685. 77% of the analysed respondents were men and 60% were MSM, 20% heterosexual women and 14% heterosexual men. Median age was 35 years and median time in Spain was 9 years. The region of origin were Europe 17%, Latin America 64%, Sub Saharan Africa 13% and others 6%, this trend is reflective of the large numbers of Latin American people migrating to Spain and so mirrors broader population trends. A total of 72% of the sample were estimated to have acquired HIV whilst living in Spain. Factors associated with post migratory acquisition were Latin American origin, younger age and increased duration of stay in Spain and the proportion was also higher in MSM. This highlights 2 key populations that are being failed with regards to prevention, migrants (especially Latin American) and MSM and suggests who needs targeting in national prevention strategies, such as PrEP.
The second presentation presented data collected on transactional sex in MSM from Vancouver, Canada and has been blogged about by one of my colleagues, so I will only briefly touch on this presentation as it has been covered more extensively elsewhere. The motivation for this study was to ascertain whether transactional sex in MSM is a causative factor in HIV transmission. The study objectives were to determine prevalence of transactional sex events and evaluate temporal trends and consequences such as HIV risk or acquisition in a prospective cohort study. Results of 690 participants and 8990 sexual events revealed that transactional sex was rare with 2.4% reporting receiving, 1.2% reporting giving, 0.3% reporting both giving and receiving. To assess HIV risk, the investigators focussed on condomless anal sex and HIV concordance, discordance and unknown status and there was no statistically significant difference between these groups and whether they engaged in transactional sex or not. Factors that did increase the risk of transactional sex included low income, loneliness, substance use of the partner (GHB and methamphetamine) and meeting online.
A third presentation of a study nested into France’s Ipergay study presented data about the suitability of on demand PrEP for chemsex participants. The objectives of this sub study were to better characterise chemsex participants and study the association between engagement in chemsex and PrEP use. Chemsex participants were found to be more likely to use anxiolytic medications, be sensation seeking and have increased numbers of sexual encounters. They were also more likely to have condomless anal sex, hardcore sexual practices and perceive themselves to be at higher risk of HIV. What was notable was that they were also more likely to use PrEP perhaps due to their justifiably perceived higher risk.
Fourth was a study from south Africa on health outcomes of children of female sex workers, who have about a 60% HIV prevalence rate. This was undertaken in the form of a cross sectional study at sex work venues and mobile health centres from September 2015- February 2016. The mothers completed a questionnaire and HIV testing. The children were also tested for HIV and growth parameters measured. Results demonstrated maternal HIV prevalence at 67.5% and ART at 63.6% and overall HIV prevalence in their children was 3%, rising to 4.5% in HIV positive mothers. Full vaccine coverage decreased as the children got older and 27% of children’s growth was stunted, a reflection of their nutritional status. This study really highlighted that health services for sex workers would be well placed to expand into caring for the children of their key population as well.
The Vietnamese DRIVE-IN study presented data on HIV and HCV incidence and risk in people who inject drugs in a longitudinal follow up of 204 eligible participants. Of the 204, 105 were HCV positive only, 94 were negative for both HIV and HCV and 5 were HIV positive only. No HIV seroconversions occurred during the 1 year follow up period but 18 HCV seroconversions occurred. Factors associated with HCV seroconversion included more injections and being arrested. This data supported the perception that HIV was low in this population but also brought to light that HCV needs to be addressed as a priority for this population.
Finally, data from a Kirby institute run, multi-site Opposites Attract trial presented more data to support treatment as prevention in male serodiscordant couples. A total of 358 couples enrolled worldwide and the total couple year follow up was 591 years. During this time, 3 seroconversions occurred. All 3 seroconversions reported condomless anal sex outside the principal relationship and phylogenetic analysis of the seroconverted participants and their principal partner demonstrated overwhelmingly that there were no linked transmissions. The data demonstrated that in over 12,000 acts of condomless anal sex with a virally suppressed HIV positive partner and a HIV negative partner not on PrEP, there were no transmissions of HIV.