A study led by the University of Leeds has developed a new model for predicting the effects of climate change on malaria transmission in Africa. Previous methods relied on rainfall totals to indicate suitable breeding grounds for mosquitoes, but the new approach incorporates various climatic and hydrological models to provide a more comprehensive understanding of malaria-friendly conditions on the continent. The research found that waterways, such as the Zambezi River, play a significant role in the spread of the disease, with a larger population living in areas conducive to malaria transmission than previously estimated. This groundbreaking research, titled “Future malaria environmental suitability in Africa is sensitive to hydrology,” was funded by the Natural Environment Research Council and published in the journal Science.
Dr. Mark Smith, an Associate Professor in Water Research at the Leeds’ School of Geography and lead author of the study, emphasized the importance of this new model in estimating the future impact of climate change on malaria transmission. By incorporating detailed estimates of water flows, the researchers can direct malaria interventions more effectively and efficiently. This is particularly crucial in regions with limited health resources. Malaria is a climate-sensitive disease responsible for 608,000 deaths among 249 million cases in 2022, with 95% of global cases reported in Africa. Reductions in malaria cases in Africa have slowed or even reversed in recent years, partly due to decreased investments in global malaria control efforts.
The researchers predict that climate change-induced hot and dry conditions will lead to a decrease in areas suitable for malaria transmission from 2025 onwards. The new hydrology-driven approach demonstrates that changes in malaria suitability will vary across different regions and are more sensitive to future greenhouse gas emissions than previously assumed. For example, reductions in malaria suitability in West Africa are more extensive than earlier models suggested, extending as far east as South Sudan. Conversely, increases in malaria suitability in South Africa are now linked to watercourses like the Orange River. Professor Chris Thomas from the University of Lincoln, a co-author of the study, highlighted how the models account for the movement of water and breeding conditions for mosquitoes along major river floodplains in arid, savannah regions common in Africa.
Professor Simon Gosling from the University of Nottingham, a co-author of the study, commended the collaboration between the research community to compile estimates of climate change impacts on water flows globally. The study underscores the intricate relationship between surface water flows and malaria transmission risks across Africa, illustrating that changes in malaria risk may come at the expense of water availability and an increased risk of other diseases like dengue. The researchers aim to further refine their models to provide more detailed insights into waterbody dynamics, which could better inform national malaria control strategies. Dr. Smith emphasized the potential for future advancements in the model to identify mosquito species likely to breed in specific habitats, allowing for more targeted interventions against these insects.
Overall, the new model developed by the University of Leeds offers a more sophisticated understanding of climate change’s impact on malaria transmission in Africa. By incorporating detailed hydrological processes and climate models, the research provides valuable insights into the changing patterns of malaria suitability on the continent. With the potential to guide more targeted and efficient malaria control strategies, this research is a significant step towards combating the spread of the disease in regions with limited resources. The study highlights the complex interplay between water dynamics, climate change, and disease transmission, underscoring the importance of holistic approaches to addressing public health challenges in the face of a changing climate.