I am an epidemiologist with a strong interest in addressing questions of public health significance. I have worked on design and analysis of HIV observational study research (including with EuroSIDA, UK CHIC, UK HIV Drug resistance database, UK Seroconverter Register, CASCADE, and COHERE), the PARTNER study(which led to the U=U statement), and randomized trials (SMART, START). I also work on HIV modelling and economic evaluation, particularly in the context of sub-Saharan Africa, using the individual-based HIV Synthesis model. I currently am responsible for convening the HIV Modelling Consortium (http://hivmodeling.org). I also have an interest in modelling of a broader range of diseases in the context of a model of the health care systemin sub-Saharan Africa.