Leading malaria experts say this could be a game-changer in the fight to eliminate malaria in Asia-Pacific and South America.
“This is a novel use of prophylaxis for people living in endemic areas. Previously prophylaxis had been thought of mainly as something for travellers from rich countries and not an elimination tool for communities with malaria. And it is a strong result,” said Prof Richard Maude, of the University of Oxford and the Mahidol Oxford Tropical Medicine Research Unit (MORU), Bangkok.
Malaria in the eastern Greater Mekong subregion has declined to historic lows. Countries in the Greater Mekong subregion are accelerating malaria elimination in the context of increasing antimalarial drug resistance. Infections are now increasingly concentrated in remote, forested foci. No intervention has yet shown satisfactory efficacy against forest-acquired malaria – until now.
Conducting an open-label, individually randomised controlled trial in Cambodia, the researchers gave randomly allocated recruited participants aged 16–65 years staying overnight in forests either a placebo of multivitamins or antimalarial chemoprophylaxis, a 3-day course of twice-daily artemether–lumefantrine, followed by the same daily dosing once a week while travelling in the forest and for a further 4 weeks after leaving the forest.
Percentage of participants with malaria infection over time
Participants receiving the antimalarial were found to be 6 times less likely to have malaria parasites or clinical malaria© The Lancet ID 2022.
Funded by the Global Fund to Fight AIDS, Tuberculosis and Malaria and Wellcome Trust, the study found that antimalarial chemoprophylaxis with artemether–lumefantrine was well tolerated and substantially reduced the risk of malaria.
This study adds to existing evidence for the efficacy and tolerability of antimalarial chemoprophylaxis in groups at high risk of malaria in low-endemic settings. It demonstrates that chemoprophylaxis is effective to prevent malaria in forest goers and can be safely managed with relatively low-intensity monthly follow-up through close engagement with, and involvement of, the local community. Malaria chemoprophylaxis among high-risk groups such as forest goers could be a valuable additional tool for malaria elimination in the Greater Mekong subregion.
The Global Fund to Fight AIDS, Tuberculosis and Malaria; Wellcome Trust.
Antimalarial chemoprophylaxis for forest goers in southeast Asia: an open-label, individually randomised controlled trial. Tripura R, von Seidlein L, Sovannarath S, Peto TJ, Callery JJ, Sokha M, Ean M, Heng C, Conradis-Jansen F, Madmanee W, Peerawaranun P, Waithira N, Khonputsa P, Jongdeepaisal M, Pongsoipetch K, Chaotthanawathit P, Soviet U, Pell C, Juanguppama J, Hekl H, Tarning J, Imwong M, Mukaka M, White NJ, Dondorp AM, Maude RJ. THE LANCET ID. Published: September 26, 2022.
In conversation with…Richard Maude. Richard Maude discusses a new article in The Lancet Infectious Diseases that assesses the efficacy of malaria chemoprophylaxis among forest goers in Cambodia.