A mosquito-borne disease that causes fevers and chills and kills around 600,000 people worldwide every year. Only female mosquitoes bite and spread the parasite. The burden falls overwhelmingly on Africa.
Global warming is expected to stymie the fight against malaria. By 2050 some 1.3bn Africans will live in areas where, because of climate change, the disease will be harder to eradicate than it is today, according to the Malaria Atlas Project (MAP). MAP estimates that unless efforts to control malaria improve, changing weather patterns will cause an extra 550,000 malaria deaths between 2030 and 2049. Some 90% of those extra deaths are projected to come from extreme weather, mostly because floods deprive people of shelter and access to medicine. Warmer weather lengthens malaria seasons and speeds up the mosquito life cycle; heavier rains create breeding grounds. Climate change will redistribute the burden into regions where people have less natural resistance. Some areas, including parts of the Sahel, may grow too hot for mosquitoes, but these tend to be thinly populated.
Southern Africa is suffering a malaria surge. In 2023 Mozambique had roughly 9m cases; South Africa had only 5,000, thanks to a cooler, drier climate and decades of organised mosquito control. But parts of South Africa are expected to become warmer, wetter and more hospitable to mosquitoes. Migrant workers from neighbouring countries can bring the parasite across South Africa's nearly 5,000km of land borders.
In the 1970s Tu Youyou extracted artemisinin from sweet wormwood (Artemisia annua), a plant admired in Chinese traditional medicine. The compound proved powerfully effective against the malaria parasite, but its efficacy faded fast when used alone, requiring seven days of treatment. Nick White of the Mahidol Oxford Research Unit in Bangkok realised it had to be paired with a longer-lasting drug. The resulting artemisinin combination therapy (ACT), taken as pills, cured 98% of non-severe cases with few side-effects. In 2006 the WHO recommended ACT as first-line treatment for non-severe malaria. In severe cases, injection of the derivative artesunate reduced mortality in adults by 34.7% compared with injected quinine. Between 2000 and 2015, deaths from malaria fell by more than a third. But by 2009 the parasite had begun to develop resistance to artemisinin, prompting research into triple-combination therapies.
Two new malaria vaccines are available, both of which prevent roughly half of cases in children under five. Pilots in Ghana, Kenya and Malawi showed a 13% drop in overall child mortality. Children are now receiving the jab in more than 20 countries.
At a lab in Johannesburg, male mosquitoes are zapped with gamma rays to render their sperm infertile, then released into the countryside to mate with females, which then lay eggs that never hatch. Increasing heat may make people more reluctant to use insecticide-treated bednets, undermining one of the most effective existing tools.
A study found that a 10% fall in malaria incidence was associated with an increase in income per person of nearly 0.3%. Feverish workers are less productive, sick children learn less, and the burden of caring for ill children falls disproportionately on mothers.
Die, v.: To stop sinning suddenly.