Containing parasite resistance to anti-malarial medicines, including artemisinin, is a critical focus of Malaria Consortium’s work in Asia. Since there are no equally effective alternative drugs, the spread of artemisinin resistance through Asia to Africa could be a catastrophic setback to global efforts to control malaria. In Asia, Malaria Consortium has been working closely with the WHO, National Malaria Control programmes and other partnes to respond to this potentially catastrophic situation. Find out more about our work here.
Early signs of resistance to arteminisin were first reported in 2007-2008 and was reported on the Cambodia-Thailand border in 2009. It has since been reported in Myanmar and Vietnam. Although the rapid emergence of anti-malarial drug resistance in this region is not well understood, there are many factors that are thought to contribute.
Drug resistance can develop through genetic mutations of wild-type genes in the parasite rendering them no longer susceptible to antimalarial drugs treatment. The use of antimalarial drugs in patients with parasites containing mutations can eliminate susceptible parasites, but leave resistant mutants to survive and reproduce.
Artemisinin monotherapies (single drug treatments) have been widely available and extensively used in Cambodia where a significant proportion of people seek treatment from the private sector. These artemisinin monotherapies are cheaper than ACTs, and are perceived to have fewer side-effects.
Lack of compliance and adherence
Multiple-day treatment regimens make it difficult for patients to finish their full course of treatment. This results in inadequate drug dosing although it is not known whether this is likely to accelerate the development of drug resistance.
Counterfeit and substandard drugs
Counterfeit and substandard drugs are widely available and well-documented in this part of the world. Inadequate dosing from ineffective or poor quality drugs not only increases the potential for development of drug resistance but also contributes to the prolonged infectiousness of a patient.
Self treatment in the private sector
It has been estimated that up to 70% of Cambodian patients seek treatment for malaria from the private sector. Private drug vendors are generally motivated to sell the drugs their customers seek and can afford. Despite the recent ban on the sale of artemisinin monotherapies in Cambodia, ensuring compliance and enforcement of this policy will remain a challenge.
Mobile and migrant populations
This region has a highly mobile population with people moving both internally and internationally, previously mainly for gem mining, forestry and political unrest and more recently for seasonal agricultural work. The economic downturn with closure of factories has driven more people to seek a living in rural areas. These populations are difficult to locate for education and treatment, as well as having a high potential to spread resistant parasites from one area to another. Innovative strategies and approaches are needed to reach these hard to reach populations.