Geographical drivers & climate-linked dynamics of Lassa fever in Nigeria

The Sentinel Forecasting team, joint second prize winners of our inaugural Challenge, has published their research on Lassa fever.

Lassa fever is a longstanding public health concern in West Africa. The virus which causes the fever is a WHO-listed priority pathogen, and although it is often framed as a global health threat, it is a neglected, endemic zoonosis.

Recent molecular studies have confirmed the fundamental role of the rodent host (Mastomys natalensis) in driving human infections, but control and prevention efforts remain hampered by a limited baseline understanding of the disease’s true incidence, geographical distribution and underlying drivers.

The Sentinel team's research, published in the journal Nature, shows that the occurrence and incidence of Lassa fever is influenced by climate, poverty, agriculture and urbanisation factors.

However, heterogeneous reporting processes and diagnostic laboratory access also appear to be important drivers of the patchy distribution of observed disease incidence.

Using spatiotemporal predictive models we show that including climatic variability added retrospective predictive value over a baseline model (11% decrease in out-of-sample predictive error). However, predictions for 2020 show that a climate-driven model performs similarly overall to the baseline model.

Overall, with ongoing improvements in surveillance there may be potential for forecasting Lassa fever incidence to inform health planning.

Images: Balaji Srinivasan/Pexels; Remy Ajenifuja/Unsplash