NCHIV plenary speaker, Tim Hallett, on the ECDC model and the UNAIDS estiamtes

Tim Hallett.jpgAt NCHIV 2015, Professor Tim Hallett of Imperial College London, spoke about the role of mathematical modelling in estimating the size of the global HIV epidemic. In his work, Professor Hallett  focuses on mathematical modelling of the HIV epidemic globally, looking at surveillance and policy.  He is also involved in in the UNAIDS modelling projects. In his talk at NCHIV, Prof. Hallett discussed the different methods currently used for HIV estimates. Speaking before NCHIV about the new ECDC modelling tool, he says “It’s always exciting to see new tools be brought into this area and this method has much to recommend it. It’s important to understand why different methods yield different results, and to ensure that uncertainties are fully propagated to the estimates. I believe the approach used in the tool is also becoming more widely used out of Europe as well.”  He explains that the UNAIDS modelling project is a large, collaborative project developed by a global reference group that continuously reviews the various methods in use throughout the world. In light of the recent launch of the ECDC model, we asked Prof. Hallett if there were plans to review the UNAIDS model. He answered that the model is continuously being updated, saying ‘Right now, we are pushing to have the model use more of the data that we anticipate becoming available and equipping them to be able to answer the questions surveillance programmes are asking – such as geographical heterogeneity in the epidemic.’ According to Prof. Hallett, the use of mathematical modelling in estimating HIV populations has made enormous progress and, in the future, he envisages models being able to make better use of the increasing amount of information being generated by surveillance programmes. Finally, he feels there is also a need for more validation and testing of models.