Changes in climate will cause a net decrease in the number of locations in Africa suitable for malaria transmissions from 2025, new research shows.
Malaria is a climate-sensitive disease that caused 619,000 deaths in 2021 against over 247 million cases.
The reduction in cases in Africa has slowed, or even reversed, in recent years, due to less investment in malaria control on a global scale. This makes understanding malaria transmission and the causes behind it even more vital.
New research supports the idea that locations suitable for transmission of the disease will decrease after the next few years due to changes in the amount of surface water and temperature.
The new research paper, published in Science, highlights how pronounced the effect of climate change is on malaria prevalence, particularly in Africa.
Using global hydrological models, experts from the University of Leeds, Nottingham, Lincoln and Namibia, showed that an initial increase in areas of transmission for malaria was possible until 2025. This would then be followed by an overall decline through the rest of the century.
Estimates highlighted that areas experiencing increased malaria transmissions would be offset by growing areas of decreasing suitability for transmission in the coming decades.
Changes in malaria transmission are complex, however, and not driven by climate changes alone.
Whilst rivers have acted as centres for malaria in the past, we find that in the future they generally become less suitable for malaria transmission because of a drying trend from global warming, especially in West Africa.
He continued: "Although an overall reduction in the future risk of malaria might sound like good news, it comes at a cost of reduced water availability and a greater risk of another significant disease, dengue.
"Our study highlights the complex way that surface water flows change the risk of malaria transmission across Africa, made possible thanks to a major research programme conducted by the global hydrological modelling community to compile and make available estimates of climate change impacts on water flows across the planet."
Dr Mark Smith, an Associate Professor in Water Research in the Leeds' School of Geography and lead author of the study, said: "This will give us a more physically realistic estimate of where in Africa is going to become better or worse for malaria.
"And as increasingly detailed estimates of water flows become available, we can use this understanding to direct prioritisation and tailoring of malaria interventions in a more targeted and informed way. This is really useful given the scarce health resources that are often available."
