Prevalence of molecular markers of artemisinin and lumefantrine resistance among patients with uncomplicated Plasmodium falciparum malaria in three provinces in Angola, 2015

Abstract

BackgroundArtemisinin-based combination therapy is the first-line anti-malarial treatment for uncomplicated Plasmodium falciparum infection in Angola. To date, the prevalence of polymorphisms in the pfk13 gene, associated with artemisinin resistance, and pfmdr1, associated with lumefantrine resistance, have not been systematically studied in Angola.MethodsDNA was isolated from pretreatment and late treatment failure dried blood spots collected during the 2015 round of therapeutic efficacy studies in Benguela, Lunda Sul, and Zaire Provinces in Angola. The pfk13 propeller domain and pfmdr1 gene were sequenced and analysed for polymorphisms. Pfmdr1 copy number variation was assessed using a real-time PCR method. The association between pfmdr1 and pfk13 mutations and treatment failure was investigated.ResultsThe majority of pretreatment (99%, 466/469) and all late treatment failure (100%, 50/50) samples were wild type for pfk13. Three of the pretreatment samples (1%) carried the A578S mutation commonly observed in Africa and not associated with artemisinin resistance. All 543 pretreatment and day of late treatment failure samples successfully analysed for pfmdr1 copy number variation carried one copy of pfmdr1. The NYD haplotype was the predominant pfmdr1 haplotype, present in 63% (308/491) of pretreatment samples, followed by NFD, which was present in 32% (157/491) of pretreatment samples. The pfmdr1 N86 allele was overrepresented in day of late treatment failure samples from participants receiving artemether–lumefantrine (p value 0.03).ConclusionsThe pretreatment parasites in patients participating in therapeutic efficacy studies in 2015 in Angola’s three sentinel sites showed genetic evidence of susceptibility to artemisinins, consistent with clinical outcome data showing greater than 99% day 3 clearance rates. The lack of increased pfmdr1 copy number is consistent with previous reports from sub-Saharan Africa. Although pfmdr1 NYD and NFD haplotypes were overrepresented in artemether–lumefantrine late treatment failure samples, their role as markers of resistance was unclear given that these haplotypes were also present in the majority of successfully treated patients in the artemether–lumefantrine treatment arms.Electronic supplementary materialThe online version of this article (10.1186/s12936-018-2233-5) contains supplementary material, which is available to authorized users.

Efficacy and safety of artesunate-amodiaquine and artemether-lumefantrine and prevalence of molecular markers associated with resistance, Guinea, 2016

“…This finding is similar to those from studies in Africa [9,29,[40][41][42][43][44] reporting a lack of the pfk13 mutations associated with artemisinin combination therapeutic resistance that have been identified in Southeast Asia [40,[45][46][47][48].…”

“…Additionally, all D0 samples and Day of Failure samples from late treatment failures were systematically amplified and sequenced for pfk13 and pfmdr1 resistance genes following previously described methodologies [29]. Molecular analyses were performed in collaboration with the U.S.…”

Efficacy and safety of artesunate-amodiaquine and artemether-lumefantrine and prevalence of molecular markers associated with resistance, Guinea: an open-label two-arm randomised controlled trial

“…Absence of pfk13 mutations associated with artemisinin resistance is further evidence that parasites remain susceptible to artemisinin derivatives in Guinea. This nding is similar to those studies in Africa [11,30,[39][40][41][42] reporting a lack of the pfk13 mutations associated with artemisinin combination therapeutic resistance that have been identi ed in Southeast Asia [40,[43][44][45].…”

“…Additionally, all D0 samples and Day of Failure samples from late treatment failures were systematically ampli ed and sequenced for pfk13 and pfmdr1 resistance genes following previously described methodologies [30]. Molecular analyses were performed in collaboration with the U.S Centers for Disease Control and Prevention (CDC) laboratories in Atlanta, USA as part of the PMI-supported Antimalarial Resistance Monitoring in Africa (PARMA) Network [31].…”

Plasmodium Falciparum Multidrug Resistance Gene-1 N86Y-Y184F-D1246Y Polymorphisms in Northern Nigeria: Implications for the Continued Use of Artemether-Lumefantrine in the Region

“…There has been recent report of AL failure in Northern Nigeria [5]. Mutations in several genes, including pfmdr1, pfcrt and pfk13 are associated with variation in parasite sensitivity to a range of drugs [6,15,26]. The pfmdr1 mutations N86Y, Y184F and D1246Y SNPs are thought to modulate susceptibility to CQ, AL and AS-AQ [53].…”