Malaria treatments ineffective against drug-resistant parasites in Cambodia

NIH reveals that Cambodia's first-line malaria defense is no longer effective. | Courtesy of
Researchers from the National Institute of Allergy and Infectious Diseases (NIAID), a branch of the National Institutes of Health (NIH), found that the first-line malaria treatment being used in Cambodia is ineffective because the parasites have developed resistance.

The treatment, dihydroartemisinin-piperaquine, contains piperaquine and artemisinin. The parasites are resistant to both of these drugs, which are in the artemisinin combination therapy (ACT).

Although drug resistance against artemisinin throughout Southeast Asia is a common fact among the science community, this is the first time that there has been straightforward evidence that the parasites are resistance to piperaquine as well.

The study involved 204 people with malaria, with ages ranging from two to 65 years old. They were located within three areas inside Cambodia. All of them had different levels of resistance of the drug. The patients’ parasite levels were observed fore exactly 63 days. Researchers saw that for 45.7 percent of the participants, the parasites reemerged after initial clearance.

Further studies demonstrated that a type of artemisinin, called artsunate, can be used with mefloquine, another long-lasting partner drug, and may be useful as first-line ACT in place of the typical dihydroartemisinin-piperaquine treatment.

The locations with the most ACT resistance are Preah Vihear and Pursat. Artemisinin is still effective in Ratanakiri, which doesn’t have as much resistance to the drug.

Organizations in this story

National Institute of Allergy and Infectious Diseases (NIAID) 5601 Fishers Lane, MSC 9806 Bethesda, MD 20892-9806

National Institutes of Health 9000 Rockville Pike Bethesda, MD 20892

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