Impact of the Global Fund Regional Artemisinin-resistance Initiative on malaria control and elimination in the Greater Mekong subregion of southeast Asia.

Responding to the emergence of Plasmodium falciparum partial resistance to artemisinins and partner drugs of artemisinin-based combination therapies in the Greater Mekong subregion (GMS) of southeast Asia, the Regional Artemisinin-resistance Initiative (RAI) was established in 2014 and has made remarkable progress in eliminating falciparum malaria. In Cambodia, Laos, and Viet Nam, the number of malaria cases has declined from hundreds of thousands in 2010 to 2313 cases in 2023, with only 246 caused by falciparum malaria. The key components of this success have been an effective package of interventions curbing malaria transmission, with an emphasis on early diagnosis and treatment in hard-to-reach populations through an extended and well organised network of community and mobile malaria workers; improved surveillance systems; and evidence-driven implementation of intensified approaches such as active case detection, chemoprevention in specific risk groups, and targeted drug administration. The RAI is funded by the Global Fund to Fight AIDS, Tuberculosis and Malaria and governed by a closely collaborating Regional Steering Committee, including technical partners, key development partners, and stakeholders from ministries of health, national malaria control programmes, civil society organisations, the private sector, academia, and regional multilateral organisations. The RAI has brought the countries of the eastern GMS close to eliminating P falciparum, the deadliest malaria-causing Plasmodium species. Nonetheless, a worrying rise in malaria cases in Myanmar with cross-border spillover requires urgent action. Lessons learned from the RAI's approach to antimalarial drug resistance in the GMS can inform countries in sub-Saharan Africa, where artemisinin partial resistance has now also emerged.