In this review article we summarize the current evidence regarding the observed relative risks of HIV transmission for each different types of sex act, relationship type and the strategies that have been tested to interrupt transmission.

No abstract

HIV pre-exposure prophylaxis (PrEP) has proven efficacy in reducing the risk of HIV infection in men who have sex with men (MSM), but has not yet been commissioned in the UK. The aim of this study was to investigate perceived need and benefit (or experience of) PrEP among HIV-negative MSM attending sexual health clinics. HIV-negative MSM attending three sexual health centres in London, UK were opportunistically invited to complete a questionnaire. Data collected comprised demographic data and sexual and drug use behaviours as well as questions regarding perceptions of risk and need for PrEP. Logistic regression analysis was undertaken to identify variables predicting acceptability of, and intention to use, PrEP. In addition, data were gathered in respondents already taking PrEP. Eight hundred and thirty-nine questionnaires were analysed. The median age of respondents was 35 years (IQR 28-41, range 18-78), 650 (77%) were of white ethnicity and 649 (77%) had a university education. Four hundred and fifty-six (54%) reported at least one episode of condomless anal sex in the preceding three months, 437 (52%) reported recreational drug use in the preceding three months and 311 (37%) had been diagnosed with a sexually transmitted infection within the preceding six months. Four hundred and sixty-three (64%) of 726 strongly agreed with the statement 'I think I would benefit from PrEP'. Multivariate logistic regression analysis demonstrated that having receptive anal intercourse (RAI) without condoms, having an awareness of the risk of unprotected RAI and having belief in the effectiveness of PrEP were independent predictors for someone thinking they would benefit from taking PrEP. Eight percent of respondents (59/724) had already taken or were currently taking PrEP. The results suggest that individuals at risk are likely to perceive themselves as benefiting from PrEP. The majority perceived their risk of acquiring HIV and benefit from PrEP accurately. Overall they appeared to have little concern over the use of PrEP and generally positive attitudes. Further investigation is warranted to understand why those at risk do not perceive benefit from PrEP.

Approximately 13% of people living with HIV in the UK are undiagnosed which has significant implications in terms of onward transmission and late diagnosis. HIV testing guidelines recommend routine screening in anyone presenting to healthcare with an HIV indicator condition (IC); however, this does not occur routinely. This study aimed to assess the feasibility and effectiveness of using case note prompts highlighting the presence of an IC to increase HIV testing. Clinicians in three outpatient departments received case note prompts either before or after a period of clinician-led identification. Test offer and uptake rates were assessed. A parallel anonymous seroprevalence study estimated the prevalence of undiagnosed HIV. A total of 4191 patients had an appointment during the study period; 608 (14.5%) had an IC. HIV test offer was significantly higher when a prompt was inserted into notes (34.3% versus 3.2%, p < 0.001). The prevalence of diagnosed HIV in the cohort was 4.1%. No cases of undiagnosed HIV infection were identified. Despite guidelines, offer of HIV testing is low. Strategies to increase routine screening of patients presenting with an IC are needed. Individual case note prompts significantly increase HIV test offer; however, the effect is lost if the strategy is withdrawn.

Lymphogranuloma venereum (LGV) is an established cause of proctitis in men who have sex with men (MSM). Currently in the UK, testing for pharyngeal Chlamydia trachomatis (CT) is not routine, and LGV typing is usually only performed in patients with anorectal symptoms. We report four cases where LGV-associated CT DNA was detected from the pharynx in MSM, demonstrating that nucleic acid amplification testing (NAAT) can be used for detecting and typing pharyngeal CT infection. These cases also highlight other possible routes of infection for LGV, and add to the broad spectrum of clinical presentations associated with this infection.