Evidence before this study

The UN Sustainable Development Goals (SDGs) include the target to end HIV as a public health threat by 2030. To achieve this target, HIV elimination strategies in developed countries have included increased testing, and treatment as prevention, with pre-exposure prophylaxis (PrEP) now considered the best strategy to prevent HIV transmission among men who have sex with men (MSM). In England in 2013, a back-calculation analysis of various HIV surveillance data found that a decade of test-and-treat strategies had not been able to detectably reduce HIV incidence in MSM by the end of 2010. This work led to the advocacy to rethink HIV prevention strategies. Since 2011, test-and-treat measures have been intensified, and PrEP uptake progressively increased among MSM from 2016. A decrease in the number of new diagnoses among this group has been evident since 2015. However, it is unclear whether this decrease was due to reduced HIV incidence, and, if so, when a reduction in incidence began and what might explain it. We searched studies on PubMed related to both estimating HIV incidence in MSM and HIV elimination prospects. We undertook two searches, using a 2010–20 data range and no language restrictions. For the first search we used the keywords (estimating or estimation) AND (hiv or HIV) AND (incidence) AND (men who have sex with men OR msm OR MSM), yielding 1648 results; for the second search we used the keywords (hiv or HIV) AND (elimination) AND (public health), yielding 2197 results. We further checked for related studies by research groups linked to public health bodies in resource-rich countries, such as Australia, Canada, Denmark, the Netherlands, and the USA. We found no work comparable to our methodology that was being implemented as a component of routine surveillance.

Added value of this study

This study presents results from a novel, age-stratified back-calculation based on routinely collated HIV surveillance data to the end of 2018. Our method allowed estimation of age-specific trends in HIV incidence, undiagnosed prevalence, and time to diagnosis, and facilitated a principled incidence extrapolation to 2030. We estimated that the peak in new HIV infections occurred in 2012 or 2013, followed by a sustained decline to 2018, with this decrease particularly marked in young MSM. Through extrapolation, we evaluated the likelihood of England reaching the UN SDG elimination target by 2030 (in England, a target of less than one newly acquired infection per 10 000 at risk per year), and identified relevant age-specific targeting of further prevention efforts (ie, to MSM aged ≥45 years) to increase this likelihood. This work could not formally attribute cause or quantify the contributions of different components of combined HIV prevention to decreasing HIV incidence. However, our results show that the decrease in incidence began before the widespread roll-out of PrEP. Therefore, testing and treatment measures might have had an effective role in decreasing HIV in MSM in a resource-rich country against a backdrop of increasing incidence of sexually transmitted infections.

Implications of all the available evidence

In England, the amplified test-and-treat strategies since 2011 have been associated with a decrease in new HIV infections among MSM, ahead of the scale-up of PrEP. This conclusion can only be drawn from the estimated trends in HIV incidence, which show a decrease in transmission before the observed decrease in number of HIV diagnoses. Additionally, given a clear definition of HIV elimination in MSM, we have proposed a method for forecasting and quantifying the prospect of eliminating HIV transmission by 2030. Our study shows that elimination of HIV transmission, as defined by the UN SDG 2030 target, is a feasible aim in England, particularly as the full effect of widening access to PrEP is yet to be identified and might consolidate the estimated decrease in HIV incidence. Vital components of reaching the 2030 target will be ensuring that an increased number of MSM test more frequently, and that high rates of treatment access are maintained in the coming years.