Quantifying the drivers of HIV transmission and prevention in men who have sex with men: a population model-based analysis in Switzerland.

By combining observational data on the relevant epidemiological and clinical processes with a mathematical model, we showed that the 'test and treat' approach is most effective in reducing the number of new cases. Only a moderate population-level effect was estimated for early initiation of ART and a weak effect for the change in condom use of diagnosed MSM. Protecting HIV-negative individuals who are not using condoms with PrEP was shown to have a major impact.