Dihydroartemisinin–Piperaquine Failure in Cambodia

This letter suggests that rising treatment failures and parasite clearance times and decreasing piperaquine sensitivity 3 years after widespread introduction of artemisinin–piperaquine indicate rapidly emerging resistance to both artemisinin and piperaquine. To the Editor: Dihydroartemisinin–piperaquine, one of the last remaining medications effective against multidrug-resistant Plasmodium falciparum, was adopted as the first-line antimalarial agent in Cambodia in 2010. 1 We are conducting a trial (ClinicalTrials.gov number, NCT01849640) evaluating the efficacy of dihydroartemisinin–piperaquine for the treatment of uncomplicated P. falciparum malaria in Oddar Meancheay Province, Cambodia. Up to 150 adult volunteers with parasite loads of 1000 to 200,000 parasites per cubic millimeter will be administered 3 days of directly observed, open-label dihydroartemisinin–piperaquine treatment (cumulative doses, 360 mg of dihydroartemisinin and 2880 mg of piperaquine), with 42 days of follow-up. Written informed consent was obtained . . .