Climate change aided malaria expansion into highland east Africa and towards the Cape in 100 years: Study

Direct links between climate, biodiversity change and disease emergence will help identify, address healthcare needs in newly vulnerable populations in future

By Rajat Ghai
Published: Wednesday 15 February 2023
Distribution of mosquito nets in Burkina Faso. Photo: iStock

Malaria-causing anopheles mosquitoes expanded their range on the African continent, reaching higher elevations and moving southwards from the equator, aided by climate change in the last century, a new study has claimed.

A team of researchers used what they termed as “one of the most comprehensive datasets ever compiled by medical entomologists to track the observed range limits of African malaria mosquito vectors from 1898 to 2016”.

They found that the anopheles species’ ranges gained an average of 6.5 metres of elevation per year and the southern limits of their ranges moved polewards 4.7 km per year.

The researchers noted that the changes in the range of the malarial vectors “would be consistent with the local velocity of recent climate change and might help explain the incursion of malaria transmission into new areas over the past few decades”.

“If confirmed, the rapid expansion of Anopheles ranges — on average, over 500 km southward and 700 metres uphill during the period of observation — would rank among the more consequential climate change impacts on African biodiversity that have been observed to date,” the study said.

The researchers’ findings challenge a long-standing assumption in historical epidemiology that mosquito ranges are mostly stationary over decades or centuries.

According to the researchers, malaria will spread into highland east Africa (the Great Rift) and expand at its southern limits (south of the Congo, towards the Cape), but transmission will likely decrease as west and central Africa become prohibitively warm.

They also stated that the direct links between climate, biodiversity change and disease emergence will be increasingly important in the future to document, quantify, identify and address real-time healthcare needs in newly vulnerable populations.

Rapid range shifts in African Anopheles mosquitoes over the last century was published in the journal The Royal Society Publishing February 15, 2023.

Read more:

Malaria cases, deaths begin stabilising after COVID disruption: WHO

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