Surveillance of antimalarial resistance molecular markers in imported plasmodium falciparum malaria cases in Anhui, China, 2012-2016

Abstract

Between2012 and2016,over 80%of registeredmalaria cases inAnhuiprovincewerePlasmodiumfalciparum returned from Africa. However, drug-resistance marker polymorphisms in imported P. falciparum cases have not been assessed. This study looked at the distribution of antimalarial-drug resistance by evaluating K13-propeller, pfmdr1, and pfcrt genemutations. Fourteen synonymous and 15 nonsynonymousmutations in the K13-propeller genewere detected in samples fromnine African countries, yet no candidate and validated K13 resistancemutations were found. The prevalence of pfcrt K76T and pfmdr1 N86Ymutantswas 27.7%and 19.9%, respectively. Six different pfcrt genotypeswere found,with C 72 V 73 M 74 N 75 T 76 being the most common (89.2%). The pfcrt 76-pfmdr1 86 haplotype combination was evaluated in 173 isolates, and the N86T76 genotype was the most prevalent (50.3%). Notably, the prevalence of the N86Y mutation in Africa marked a decline from31.0%in 2012 to 8.2%in 2016.Our findings suggest that there is no immediate threat to artemisinin efficacy in imported P. falciparum infections returned from Africa to Anhui province. Nevertheless, pfcrt K76T and pfmdr1 N86Y mutations were modestly prevalent, suggesting the presence of chloroquine resistance in these cases. Accordingly, dihydroartemisinin + piperaquine may be a better choice than artesunate + amodiaquine for the treatment of uncomplicated P. falciparum infections in Anhui province. In addition to, artemether-lumefantrine can be introduced as an alternative measure.