In England, the recent decline in new HIV diagnoses among men who have sex with men (MSM) attending sexual health clinics (SHCs) has been attributed to HIV combination prevention including HIV pre-exposure prophylaxis (PrEP). To evaluate recent trends in HIV and STI diagnoses, we determined the prevalence of bacterial sexually transmitted infections (STIs) and annual incidence of HIV in MSM attending SHCs in England.
Using GUMCAD, England’s national STI surveillance system, we extracted data on HIV (from 2012 to 2017) and bacterial STI (from 2017: chlamydia, gonorrhoea, and primary, secondary, early latent syphilis) diagnoses in MSM aged ≥16 years attending SHCs. Period prevalence and 95% confidence intervals (CIs) for HIV among all attendees and bacterial STIs (at least one diagnosis in calendar period) among HIV negative attendees in 2017 were calculated. Annual HIV incidence per 100 person-years (PY) and 95% CIs in MSM who tested for HIV at least twice in the same SHC from 2012 to 2016 were determined. As a proxy measure of high risk, HIV incidence in a subset of MSM with a history of a negative HIV test and an ano-genital bacterial STI in the preceding year was also examined.
In the 159,368 MSM attending SHCs in 2017, HIV period prevalence was 20.0% (95% CI 19.8-20.2%). In MSM not known to be HIV positive (n=128,772), gonorrhoea, chlamydia, and syphilis period prevalence in 2017 was 12.1% (11.9-12.2%), 9.0% (8.9-9.2%), and 2.7% (2.6-2.8%), respectively. The number of MSM not known to be HIV positive (% tested for HIV at least twice) increased from 85,500 (31.0%) in 2012 to 120,606 (36.2%) in 2016. The annual incidence of HIV in MSM decreased 60.5% from 2.0 per 100 PY (95% CI: 1.8-2.2) in 2012 to 0.79 per 100 PY (0.69-0.89) in 2016; compared to the latter, MSM meeting proxy high risk criteria in 2016 had a two-fold higher HIV incidence [1.58 (1.25-1.99) per 100 PY].
While there is a high prevalence of bacterial STIs, there has been a sharp decrease in the incidence of HIV in MSM regularly attending SHCs. The fall in HIV incidence coincides with further intensification of HIV testing, especially repeat testing, and earlier initiation of HIV treatment and, more recently, the scale up of privately purchased generic PrEP in England from late 2017. The PrEP Impact trial, which aims to enrol 13,000 participants from communities most affected by HIV, is likely to have an additional effect on the incidence of HIV.