title: An outbreak of artemisinin resistant falciparum malaria in Eastern Thailand.
abstract: Artemisinin resistant falciparum malaria is an increasing problem in Southeast Asia, but has not been associated with increased transmission of the disease, yet. During a recent outbreak in 2014 in Ubon Ratchatani, Eastern Thailand, parasites from 101 patients with falciparum malaria were genotyped for antimalarial drug resistance markers. Mutations in the Kelch13 marker for artemisinin resistance were present in 93% of samples, mainly C580Y from 2 major clusters as identified by microsatellite typing. Resistance markers for antifolates and chloroquine were also highly prevalent. Most strains (91%) carried single copy number PfMDR1, suggesting sustained sensitivity to mefloquine, the partner drug in the local first-line artemisinin combination therapy (ACT). The high prevalence of artemisinin resistance in this recent malaria outbreak suggests but does not prove a causative role in increased transmission. Careful monitoring of ACT efficacy and additional genetic epidemiological studies are warranted to guide the public health response to the outbreak.
authors.affiliation: Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Mallika
authors.initials: M
authors.lastname: Imwong
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Thantip
authors.initials: T
authors.lastname: Jindakhad
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Chanon
authors.initials: C
authors.lastname: Kunasol
authors.affiliation: Buntharik Hospital, Amphoe Buntharik, Ubon Ratchathani 34230, Thailand.
authors.forename: Kreepol
authors.initials: K
authors.lastname: Sutawong
authors.affiliation: Buntharik Hospital, Amphoe Buntharik, Ubon Ratchathani 34230, Thailand.
authors.forename: Phisitt
authors.initials: P
authors.lastname: Vejakama
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.|Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Arjen M
authors.initials: AM
authors.lastname: Dondorp
mesh_terms: D000293:Adolescent; D000328:Adult; D000962:Antimalarials / Q000494:pharmacology* / Q000627:therapeutic use; D037621:Artemisinins / Q000494:pharmacology* / Q000627:therapeutic use; D016000:Cluster Analysis; D004196:Disease Outbreaks; D004351:Drug Resistance; D005260:Female; D018628:Gene Dosage; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000453:epidemiology* / Q000469:parasitology*; D008297:Male; D018895:Microsatellite Repeats; D058889:Molecular Typing; D009154:Mutation; D010802:Phylogeny; D010963:Plasmodium falciparum / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D015800:Protozoan Proteins / Q000235:genetics; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D015800:Protozoan Proteins