Pfkelch13 Plasmodium falciparum Mutations in Huambo, Angola

Artemisinin (ART) is recommended as the first-line drug for P. falciparum infections combined with a long-acting partner drug. The emergence of P. falciparum resistance to ART (ARTR) is a concern for malaria. The most feared threat remains the spread of ARTR from Southeast Asia to Africa or the independent emergence of ARTR in Africa, where malaria accounts for 93% of all malaria cases and 94% of deaths. To avoid this worst-case scenario, surveillance of Pfkelch13 mutations is essential. We investigated mutations of Pfkelch13 in 78 P. falciparum samples from Huambo, Angola. Most of the parasites had a wild-type Pfkelch13 allele. We identified one synonymous mutation (R471R) in 10 isolates and one non-synonymous mutation (A578S) in two samples. No Pfkelch13 validated or candidate ARTR mutants were identified. The finding suggests that there is little polymorphism in Pfkelch13 in Huambo. Since cases of late response to ART in Africa and the emergence of ARTR mutations in Rwanda and Uganda have been reported, efforts should be made toward continuous molecular surveillance of ARTR. Our study has some limitations. Since we analyzed P. falciparum parasites from a single health facility, the study may not be representative of all Angolan endemic areas.