Climate change could affect region-wise trends in malaria, study in Kenya suggests

New Delhi: A new study in Kenya has found that despite an overall decline in malaria cases, recent trends in rainfall and temperatures driven by climate change could have helped create conditions conducive for mosquito breeding, thereby significantly increasing disease risk in northern regions.

Researchers found that while overall malaria prevalence in the African country fell from eight per cent to six per cent between 2015 and 2020, in places such as Turkana in northwest Kenya, the risk of the infectious disease increased by three to four times.

The team, including researchers from the Kenya Medical Research Institute, said that the region-specific surge of malaria cases revealed unpredictable impacts of climate change and that public health measures need to adapt swiftly to combat the spread of the disease. The findings are published in the International Journal of Health Geographics.

"By employing advanced geostatistical models based on national malaria surveys conducted between 2015 and 2020, we found that despite a decline in malaria overall, there was a significant rise in malaria risk in some regions, particularly in northern Kenya," author Bryan Nyawanda, from the Kenya Medical Research Institute, said.

"Our findings show that public health measures must adapt swiftly to combat malaria amidst changing environmental conditions," Nyawanda said.

A deadly disease that spreads through the bite of infected female Anopheles mosquitoes, malaria is a major public health issue in many developing countries, especially tropical ones whose environmental conditions are known to enable the spread of the disease.

Increasingly warmer and humid conditions driven by climate change have been predicted to enhance risk of the tropical disease in previously unaffected locations, such as those in Europe.

The Kenya study's findings of a 31 per cent reduction of malaria incidence in children aged under five, and a 26 per cent reduction in children aged 5-14 years, reflected the positive impact of disease control measures, specifically the use of insecticide-treated nets, indoor residual spraying and anti-malarial treatments, the researchers said.

Further, a weakening of the link between increased rainfall and malaria between 2020 and 2025 suggested that urbanisation and an improved infrastructure that reduced exposure of humans to mosquitoes also helped lower malaria rates, they said.

However, the rising risks in some low-risk and semi-arid (semi-dry) regions show that continued monitoring and localised interventions are essential, the authors said.

As climate patterns shift globally, countries facing similar challenges can use geostatistical models such as those from this study to better understand malaria trends and develop tailored strategies, they said.

"The changing climate calls for innovative solutions. By understanding how environmental and socio-economic factors interact, we can better allocate resources and adapt strategies to protect the most at-risk populations," Nyawanda said.