Dr Nathan Geffen will present the School of IT colloquim with a talk entitled, "How to match people in sexual relationships when modelling the HIV epidemic". 

Mathematical models of the HIV epidemic have been used to estimate incidence, prevalence and life-expectancy, as well the benefits and costs of public health interventions, such as the provision of antiretroviral treatment. Models of sexually transmitted infection epidemics attempt to account for varying levels of risk across a population based on diverse — or heterogeneous — sexual behaviour. In this colloquium Nathan Geffen will give a brief overview of how models have influenced debates on the HIV epidemic. He will then describe the advantages of using agent-based models, but also the challenge of getting them  to execute speedily because of the computationally intensive task of matching agents into sexual relationships. Geffen will present some algorithms he analysed for his PhD that speed up these simulations. 

Nathan Geffen has just graduated with a PhD in Computer Science from UCT. From 2000 to 2013 he campaigned for HIV treatment and prevention with the Treatment Action Campaign.  Nathan edits GroundUp and has also taught Computer Science courses at UCT.