Exploring the spatial epidemiology and network dynamics of onchocerciasis

Onchocerciasis, caused by the vector-borne filarial nematode Onchocerca volvulus, has been earmarked for elimination by 2020 according to the World Health Organization's roadmap on neglected tropical diseases. Most dynamic modelling studies seeking to understand the determinants and time horizons to elimination have assumed closed, isolated populations of humans, blackfly vectors and parasites. However (rural) endemic communities are likely to be connected by human and fly movement, work-related seasonal travelling patterns, between-borders migration, and in conflict zones internal population displacement. The extent to which this connectedness between transmission zones and areas with varying histories of control interventions will affect continental elimination efforts remains unknown. This project aims to understand how the transmission dynamics of onchocerciasis vary over time and space and in response to underlying network structure. As global targets approach various definitions of onchocerciasis elimination, this project aims to develop novel mechanistic and inferential models to assess intervention effect sizes, forecasting and counterfactual prediction as well as to help inform programmatically viable definitions of elimination and design of post-elimination surveillance strategies.