Artemisinin resistance: current status and scenarios for containment

Key Points Malaria, caused by Plasmodium spp., remains a tremendous disease burden worldwide, causing nearly one million deaths and 250 million cases of disease. Artemisinin and artemisinin derivatives are effective antimalarials, especially when coupled with a second, unrelated antimalarial. Owing to the use of artemisinin as a monotherapy, strains of Plasmodium falciparum have emerged that have a decreased sensitivity to the drug. Several strategies to prevent the spread of the less resistant parasites have been put in place, such as a multifaceted approach that includes early diagnosis and appropriate treatment, decreasing drug pressure, optimising vector control, targeting the mobile population, strengthening of management and surveillance systems, and operations research. Other, broader strategies can target the emergence and spread of drug resistance. These include mass drug administration, using multiple first-line therapies simultaneously, surveillance, active case investigation and focal control Artemisinin is one of the few antimalarials for which there is no widespread resistance. However, malaria parasites with decreased sensitivity have been reported recently. In this Review Arjen Dondorp and colleagues describe the initial detection of artemisinin resistance and discuss several strategies to prevent its spread. Artemisinin combination therapies are the first-line treatments for uncomplicated Plasmodium falciparum malaria in most malaria-endemic countries. Recently, partial artemisinin-resistant P. falciparum malaria has emerged on the Cambodia–Thailand border. Exposure of the parasite population to artemisinin monotherapies in subtherapeutic doses for over 30 years, and the availability of substandard artemisinins, have probably been the main driving force in the selection of the resistant phenotype in the region. A multifaceted containment programme has recently been launched, including early diagnosis and appropriate treatment, decreasing drug pressure, optimising vector control, targeting the mobile population, strengthening management and surveillance systems, and operational research. Mathematical modelling can be a useful tool to evaluate possible strategies for containment.