CLIMATE CHANGE SET TO DRIVE SHIFT IN MALARIA TRANSMISSION RISK GLOBALLY

▶ Hotter temperatures causing fall in mosquito-prone areas in Africa as Europe becomes susceptible, study shows

Climate change is set to have a significant impact in areas where malaria is prevalent, with current hotspots improving but new regions affected, a study has revealed.

Hotter and drier temperatures will drive a reduction in mosquito breeding grounds in Africa, while areas in southern Europe will become more susceptible.

Researchers studied the impact of rainfall that has caused flooding and led to the creation of surface water suitable for breeding mosquitoes.

The study, titled Future Malaria Environmental Suitability in Africa is Sensitive to Hydrology, was funded by the Natural Environment Research Council.

It revealed that climate change had already caused a fourfold increase in mosquito-prone areas and created the conditions for breeding grounds in areas such as the Nile, which have been malaria free for the past few decades.

By using the new hydrology-driven model for predicting the effects of climate change on malaria transmission, it will mean more specific interventions to control the disease can be used in areas at risk.

Dr Mark Smith, an associate professor in water research at the University of Leeds and lead author of the study, has been working in the field of malaria research for 15 years in Tanzania and Zambia.

He told The National that the research would enable health agencies in the future to identify mosquito-prone areas and which interventions to use.

“This will give us a more physically realistic estimate of where in Africa is going to become better or worse for malaria,” he said.

“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.

“Our model says even at present day, there are almost four times more people living in potentially malaria-endemic areas than we would have thought. In the future, we expect that to change. We expect to see a decrease in the areas suitable for malaria but those areas that are suitable are still around rivers and that is where the cities are.

“Those cities are going to expand massively in population and we are going to see a huge increase in the number of people in those areas, driven by population growth.”

Malaria is a climate-sensitive vector-borne disease that caused 608,000 deaths from 249 million cases in 2022.

The research showed that the number of months suitable for transmission is set to increase due to climate change, Dr Smith said, adding that their work had also highlighted the role of waterways, such as the Zambezi River and the Nile in the spread of the disease.

“We expect to see southern Europe increasing in suitability for malaria,” he said.

“We have looked at the length of transmission seasons, the number of continuous months suitable for transmission and we are seeing a likely increase in areas like southern Europe.

“We are also seeing locally acquired cases in the US, in Florida and Texas.”

Last year, scientists at Abu

Dhabi’s Forecasting Healthy Futures summit revealed malaria was re-emerging in countries such as Greece, where it had been previously eradicated, with local outbreaks reported across Europe and in Japan.

In the report, which was published on Wednesday, the researchers predicted the hot and dry conditions brought about by climate change in Africa, where 95 per cent of the world’s cases are reported, would lead to an overall decrease in areas suitable for malaria transmission from 2025 onwards.

The new hydrology-driven approach also shows that changes in malaria suitability are seen in different places and are more sensitive to future greenhouse gas emissions than previously thought.

The study showed that the number of months suitable for malaria transmission is set to rise due to climate change