Preventive drugs halve malaria infections in African school children, major study finds

Giving school-age children in Africa preventive antimalarials reduces infections by almost 50 per cent and could help eliminate the disease across the continent, experts have found. 

According to a study published in The Lancet Global Health, the prevalence of malaria among 15,000 school children fell by 46 per cent when they were given treatments to prevent infections. Subsequent cases of clinical malaria dropped by 50 per cent. 

While huge strides were made in efforts to eliminate the mosquito-borne disease between 2000 and 2015, progress since has stalled. In 2018, the latest year with available data, roughly 400,000 people died from malaria and there were 228 million cases worldwide (see chart).

But Dr Matthew Chico, assistant professor of Public Health at the London School of Hygiene and Tropical Medicine and senior author of the report, told The Telegraph that widespread rollout of preventative antimalarials could “prove a game changer” - if combined with other measures, including bednets and a vaccine. 

“We are at a bit of a crossroads, where our interventions are bearing less fruit,” he said. “This is partly because, on the pathway to malaria elimination, people who live in high transmission areas will necessarily lose some degree of acquired immunity because they are no longer exposed. 

“The risk is that, unless we continue to suppress malaria, we see a reemergence of infections. But bringing together preventative treatment for school-age children, plus a vaccine and high coverage of insecticide treated bednets, would help to bring down exposure. 

“The three-pronged approach might just produce the silver bullet we need for malaria elimination,” Prof Chico said. 

Bednets have been a central facet of efforts to eliminate malaria for decades, but it was not until last year that Malawi became the first country to use a landmark malaria jab, called RTS,S, which was developed over 30 years by the UK drug firm GSK.

While experts have conceded that the immunisation is “imperfect”, it is the only vaccine to reduce malaria infections in children, preventing around four in 10 cases. 

The Lancet study is the first systematic review of the impact of preventive malaria treatments among school-age children. 

The team collated data from 11 different clinical studies conducted between 1995 and 2019, which included 15,000 children aged 5 to 15 living in seven different countries across sub-Saharan Africa. Half were given one of a number of antimalarials, whereas the other half were either given a placebo or not treated as a control.

As well as cutting malaria incidence, cases of anemia in schoolchildren dropped 15 per cent among those who received preventive drugs. Malaria causes fevers, headaches and chills, but also triggers anemia as the parasite destroys red blood cells. 

Researchers also noted that school performance also improved among children older than 10. 

“Utilising schools as a platform to deliver preventive treatment improves the feasibility of this intervention,” said Dr Lauren Cohee, faculty member in the Malaria Research Program at the University of Maryland School of Medicine and first author of the report. 

“Preventive treatment of malaria could be added to existing school-based health programs, including nutrition and deworming, to further promote the overall health of the learner.”

Prof Chico added that focusing on reducing transmission among school age children was significant because “epidemiological shift” means an increasing proportion of infections are among this group. 

“Historically the burden of disease has predominantly been in children aged zero to five, so that's where efforts focused first, as well as in pregnant women,” he said. “But we are seeing the burden transition to older, school aged children as interventions have not targeted them previously.”

He added that a lack of semi-acquired immunity may also be contributing to this trend, as children have less exposure to malaria during their early years. “So when they are infected, it is more likely that the infection will require medical treatment,” he said. 

Currently, the World Health Organization recommends providing intermittent preventive treatment to pregnant women, infants and young children in some malaria-endemic areas, but has not issued recommendations for school-age children. Prof Chico and is confident this could soon change. 

“There's evidence to suggest that school age children are a primary driver of continued transmission, that they represent at this point really a key barrier to achieving malaria elimination,” he said. “I am optimistic that the WHO will take our findings into consideration.

“We have come a great distance and over the last fifteen years have cut malaria mortality by half,” he added. “But in the face of stalling progress to cut mortality in half again means you have to do more - the low lying fruit, as such, has already been picked.” 

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