Malaria remains a major health threat in Africa as new mosquito species spreads

Despite significant progress in malaria prevention and treatment, the disease remains one of Africa’s biggest public health challenges. In 2024, around 579,000 people died from malaria in Africa, according to the World Health Organization (WHO). Children under five accounted for roughly three-quarters of malaria deaths on the continent. The fight against the disease is also becoming more complicated with the spread of a mosquito species particularly well adapted to Africa’s rapidly growing cities.

Anopheles stephensi complicates malaria control

One of the emerging challenges is the spread of Anopheles stephensi, a mosquito species originally from South Asia.

It was first detected in Djibouti in 2012 and has since been reported in several East African countries. More recently, its presence has also been confirmed in West Africa, including Nigeria and Ghana.

What concerns malaria specialists is the mosquito’s ability to thrive in urban environments.

Unlike several traditional malaria vectors in Africa, Anopheles stephensi can breed in artificial water containers, tanks and other water-holding receptacles commonly found around homes.

This makes densely populated urban areas particularly vulnerable to its spread.

A mosquito capable of surviving extreme heat

Another worrying characteristic is the mosquito’s ability to survive very high temperatures during the dry season.

Normally, malaria transmission tends to decline during periods of extreme heat and dryness. But the resilience of Anopheles stephensi could extend the transmission season and potentially increase malaria transmission in African cities.

This is particularly concerning as the continent experiences rapid urbanisation and population growth.

Millions more people could be at risk

The potential impact could be substantial.

A modelling study cited in recent scientific research estimates that the combined effects of Anopheles stephensi expansion and urbanisation could expose more than 120 million additional Africans to malaria risk.

The emergence of this mosquito therefore adds another layer of complexity to malaria control efforts, which already rely heavily on insecticide-treated bed nets, indoor spraying, rapid diagnosis and effective treatment.

For health authorities, monitoring the spread of Anopheles stephensi and adapting mosquito-control strategies to urban environments will be increasingly important in the years ahead.