Impact of future climate change on malaria in West Africa

Ibrahima Diouf,Jacques-André Ndione,Gbenga J Abiodun,Emiola O Gbobaniyi,Abiodun M Adeola,Joyce M Shirinde,Pascal Yaka,Christopher Lennard

doi:10.1007/s00704-021-03807-6

Abstract

Understanding the regional impact of future climate change is one of the major global challenges of this century. This study investigated possible effects of climate change on malaria in West Africa in the near future (2006–2035) and the far future (2036–2065) under two representative concentration pathway (RCP) scenarios (RCP4.5 and RCP8.5), compared to an observed evaluation period (1981–2010). Projected rainfall and temperature were obtained from the coordinated regional downscaling experiment (CORDEX) simulations of the Rossby Centre Regional Atmospheric regional climate model (RCA4). The malaria model used is the Liverpool malaria model (LMM), a dynamical malaria model driven by daily time series of rainfall and temperature obtained from the CORDEX data. Our results highlight the unimodal shape of the malaria prevalence distribution, and the seasonal malaria transmission contrast is closely linked to the latitudinal variation of the rainfall. Projections showed that the mean annual malaria prevalence would decrease in both climatological periods under both RCPs but with a larger magnitude of decreasing under the RCP8.5. We found that the mean malaria prevalence for the reference period is greater than the projected prevalence for 6 of the 8 downscaled GCMs. The study enhances understanding of how malaria is impacted under RCP4.5 and RCP8.5 emission scenarios. These results indicate that the southern area of West Africa is at most risk of epidemics, and the malaria control programs need extra effort and help to make the best use of available resources by stakeholders.

Highlights

Several vector-borne diseases such as malaria are very sensitive to climate and weather conditions (Tompkins and Ermert 2013, Abiodun et al 2016, Abiodun et al 2017; Abiodun et al 2018)
In West Africa, while the rainfall season is at its peak in July–August–September, the peak of the malaria outbreak season occurs in September–October–November
Using the Liverpool malaria model, we have evaluated the ability

Summary

Introduction

Several vector-borne diseases such as malaria are very sensitive to climate and weather conditions (Tompkins and Ermert 2013, Abiodun et al 2016, Abiodun et al 2017; Abiodun et al 2018). For example, during heavy rainfall periods, mosquito populations can multiply and trigger epidemics. In desert regions and highlands bordering malaria epidemic areas, transmission is unstable, and the human population is not immune. Climate variability and change have been linked with malaria transmission in most West African countries: Benin, Burkina Faso, Cabo Verde, Côte D’Ivoire, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo (Ayanlade et al 2020, Diouf et al 2020; Makinde et al 2021). Severe epidemics can occur when atmospheric conditions (precipitation and temperature) become favorable for transmission. Malaria risk fluctuations have been associated over time with changes in rainfall in relation to El Niño (Poveda et al 2001; Gagnon et al 2002; Kovats et al 2003; Mabaso et al 2007; Hanf et al 2011)

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