New research published in Nature highlights a significant impact of climate change on malaria transmission across Africa, with East Africa experiencing an 84% increase. The study, led by Dr Colin Carlson of Yale University, analysed over a century of malaria data alongside historical climate records to isolate the effects of rising temperatures on the disease's spread.

Key Findings

  • Malaria transmission has risen by 84% in East Africa and 91% in Southern Africa due to climate change.
  • Temperature changes are shifting malaria's geographic range, increasing risk in previously cooler highland regions.
  • In West and Central Africa, higher temperatures have slightly reduced transmission as conditions exceed the optimal range for mosquitoes and parasites.
  • Public health interventions have so far had a greater impact in reducing malaria prevalence than climate change has had in increasing it.

Temperature and Malaria Dynamics

Malaria-carrying mosquitoes and parasites thrive at around 25°C. Rising temperatures in East Africa's highlands are creating more hospitable environments for malaria, exposing populations in areas once considered too cold. Conversely, parts of West and Central Africa are becoming less suitable for transmission as temperatures surpass this ideal range.

Implications and Recommendations

While climate change is reshaping malaria distribution, it remains a secondary factor compared to public health efforts such as insecticide-treated nets, indoor spraying, and improved treatments, which have reduced malaria prevalence by approximately 16 percentage points since 1900.

The study warns of the invasive mosquito species Anopheles stephensi, which tolerates hotter climates and urban environments, potentially increasing malaria risks in East African cities.

Researchers urge governments to enhance surveillance, particularly in highland and urban areas, and to maintain investment in proven malaria control measures to adapt to shifting risks.

As climate change continues, malaria control strategies must evolve to protect vulnerable communities and prevent outbreaks in newly exposed regions.