Lassa fever is a longstanding public health concern in West Africa. 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. Here, we show that Lassa fever occurrence and incidence 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.
Bibliographical noteFunding Information:
The authors thank all the epidemiologists and clinical staff at Nigeria state and LGA levels who collected and submitted the original case reports. This research was supported by an MRC UKRI/Rutherford Fellowship (MR/R02491X/1) and Sir Henry Dale Research Fellowship (funded by the Wellcome Trust and the Royal Society) (220179/Z/20/Z) (both D.W.R.), a Graduate Research Scholarship (R.G.) and Global Engagement Fund grant (D.W.R. and R.G.) both from University College London and the QMEE CDT, funded by NERC grant number NE/P012345/1 (L.A.A.). C.A.D. acknowledges joint Centre funding from the UK Medical Research Council and Department for International Development (DFID). C.A.D. acknowledges joint Centre funding from the UK Medical Research Council and Department for International Development (DFID). C.A.D. is funded by the Department of Health and Social Care using UK Aid funding on a grant managed by the UK National Institute for Health Research (NIHR) (Vaccine Efficacy Evaluation for Priority Emerging Diseases: PR-OD-1017-20007 and HPRU in Emerging and Zoonotic Infections: NIHR200907). The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Care. I.A. acknowledges funding from the UK NIHR (NF-SI-0616–10037), EDCTP PANDORA Consortium and the UK MRC. K.E.J. acknowledges the Dynamic Drivers of Disease in Africa Consortium, NERC project no. NE-J001570-1, which was funded with support from the Ecosystem Services for Poverty Alleviation Programme (ESPA). The ESPA programme was funded by DFID, the Economic and Social Research Council (ESRC) and NERC.
© 2021, The Author(s).