ART use, viral suppression, and sexual behaviour among HIV‐diagnosed MSM in the UK: results from the Antiretrovirals, Sexual Transmission Risk and Attitudes (ASTRA) Study

摘要

Objective To assess the associations of ART use, viral load (VL) suppression and transmission risk beliefs with sexual behaviour among HIV‐diagnosed men who have sex with men (MSM) in the UK. Methods ASTRA is a multicentre UK study of >3000 HIV outpatients in 2011/12. A self‐completed questionnaire defined ‘unprotected sex with an HIV‐discordant partner’ (USD) as anal or vaginal sex without a condom in the past 3 months with a partner of negative or unknown HIV status. Transmission risk belief score (TRBS) was classified as 0–2 [2: agree ‘when VL is undetectable, a condom is not needed to prevent HIV transmission’; 1: agree ‘undetectable VL makes someone less infectious to a sexual partner’ 0: do not agree with either statement]. Associations of USD with TRBS, self‐reported ART and VL status, and other factors were assessed using Chi‐squared tests and logistic regression. Results Data are available for 2086 MSM [88% white; mean age: 45 years]. 1767 (84.7%) were on ART; of whom 1470 (83.2%) reported VL≤50 c/mL, 148 (8.4%) reported VL>50 c/mL and 149 (8.4%) did not know VL status. TRBS was 0, 1 and 2 for 48.0%, 47.7% and 4.3% of MSM. Prevalence of USD was 14.8% (n=308) overall; 123 of 308 reported receptive anal sex only. USD prevalence increased with higher TRBS [8.2%, 19.4%, 35.2% for TRBS 0,1,2 respectively; p50 c/mL/unknown (14.7% vs 9.4%; p=0.016). This pattern of association between ART/VL status and USD was similar after adjustment for demographic, lifestyle, and HIV‐related factors: compared to MSM on ART with VL50 c/mL/unknown, and 1.25 (0.87, 1.79) for MSM not on ART, global p=0.006. Absence of an HIV‐positive stable partner, more recent HIV diagnosis and recreational drug use were also independently associated with USD (all p Conclusions Approximately 15% of HIV‐diagnosed MSM report recent USD. Among MSM on ART, self‐reported undetectable VL is associated with USD, suggesting that perceived VL status may influence sexual behaviour and condom use. However, prevalence of USD is also high among MSM not taking ART. These findings have implications for prevention strategies among MSM in the UK.