Molecular markers of artemisinin resistance during falciparum malaria elimination in Eastern Myanmar.
Thu AM., Phyo AP., Pateekhum C., Rae JD., Landier J., Parker DM., Delmas G., Watthanaworawit W., McLean ARD., Arya A., Reyes A., Li X., Miotto O., Soe K., Ashley EA., Dondorp A., White NJ., Day NP., Anderson TJC., Imwong M., Nosten F., Smithuis F.
BACKGROUND: Artemisinin resistance in Plasmodium falciparum threatens global malaria elimination efforts. To contain and then eliminate artemisinin resistance in Eastern Myanmar a network of community-based malaria posts was instituted and targeted mass drug administration (MDA) with dihydroartemisinin-piperaquine (three rounds at monthly intervals) was conducted. The prevalence of artemisinin resistance during the elimination campaign (2013-2019) was characterized. METHODS: Throughout the six-year campaign Plasmodium falciparum positive blood samples from symptomatic patients and from cross-sectional surveys were genotyped for mutations in kelch-13-a molecular marker of artemisinin resistance. RESULT: The program resulted in near elimination of falciparum malaria. Of 5162 P. falciparum positive blood samples genotyped, 3281 (63.6%) had K13 mutations. The prevalence of K13 mutations was 73.9% in 2013 and 64.4% in 2019. Overall, there was a small but significant decline in the proportion of K13 mutants (p