Study finds climate change likely to reduce malaria risks in Africa

The study, led by the University of Leeds predicts that the hot and dry conditions brought about by climate change will result in an overall decrease in areas suitable for malaria transmission from 2025 onwards. This is confirmed by research published in the Malaria Journal, which maps the shifting geographic risk of malaria transmission, indicating that certain regions may see a reduction in the length of malaria seasons.

Malaria, a disease transmitted by Anopheles mosquitoes, has long been a burden in Africa with children under five being overly affected. The disease's transmission is closely tied to climate conditions that are conducive to mosquito and parasite development. As such, climate changes can alter the geographic and seasonal suitability for transmission.

The University of Leeds study suggests that the increasingly inhospitable conditions for mosquitoes in some parts of Africa could lead to a reduction in malaria cases. Similarly, the Malaria Journal article highlights that while there may be a net gain in the number of people at risk due to geographic shifts, the overall trend could be a reduction in year-round transmission risk, particularly in Western Africa.

According to the study, “Future malaria environmental suitability in Africa is sensitive to hydrology,” shifting geographic risk and seasonality of malaria transmission are expected. The worst-case scenario under the RCP8.5 greenhouse gas emissions pathway predicts an additional 75.9 million people at risk from endemic exposure to malaria in Eastern and Southern Africa by 2080. However, despite a reduction in season length, a net gain of 51.3 million additional people could be at some level of risk in Western Africa by mid-century.

While the potential reduction in malaria risk is a welcome development, it is not without its challenges. Health systems in Africa, already under strain, must adapt to these changing patterns.

The Professor of Climate Risks & Environmental Modelling, who co-authored the study and assisted in orchestrating water modelling experiments, Simon Gosling, has cautioned that the climate change actions would, however, result in diminished water availability and heightened susceptibility to another notable illness, dengue.

Prior evaluations across Africa typically "solely represent surface water using precipitation". In contrast, the authors of the recent study employed a weighted ensemble of global hydrological and climate models to gauge current and projected regions of hydroclimatic suitability for malaria transmission.

A World Bank report further emphasises the worsening impact of climate change on health in Ghana, underscoring the need for improved health facilities and resources to address the evolving landscape of public health threats.