Proposal for a revised Modes of Transmission Model

The first work package initiated by the Consortium, Sources of Infection, reviewed different aspects of the Modes of Transmission model. As part of this project a number of research groups were award Request for Funding Applications to review the use and evaluate the utility of the Modes of Transmission model. The evaluative work identified some constraints of the existing model and it was agreed to extend this work package to a second phase in which the Secretariat would develop a proposal for a revised Modes of Transmission model.

The Secretariat developed a proposal for a revised model for a generalised epidemic that has been developed and tested using multiple rounds of cohort data from 4 of the ALPHA Network sites (Karonga, Kisesa, Manicaland, and Rakai). The model differs from the original version; there is a shift from reliance on behavioural data towards data on age, sex, marital status & geographical location, which should be more readily available and reliable in most country settings. Additionally, factors affecting transmission / acquisition such as circumcision and ART status have been incorporated. Further to this a rigorous method to evaluate uncertainty is to be included.

In collaboration with UNAIDS, the model was piloted in Botswana in 2015 using data from the BAIS. It is hoped that another pilot will take place in the region in due course. The HIV Modelling Consortium are to assist Avenir Health in transitioning the current model to a user-friendly platform.

A manuscript detailing the development and validation of the proposed revision to the model is currently being finalised and will be made available on the website in due course.