Ex vivo RSA and Pfkelch13 targeted-amplicon deep sequencing reveal parasites susceptibility to artemisinin in Senegal, 2017.

INTRODUCTION

Malaria control is highly dependent on the effectiveness of artemisinin-based combination therapies (ACTs), the current frontline malaria curative treatments. Unfortunately, the emergence and spread of parasites resistant to artemisinin (ART) derivatives in Southeast Asia and South America, and more recently in Rwanda and Uganda (East Africa), compromise their long-term use in Sub-Saharan Africa where most malaria deaths occur.

METHODS

Here, we evaluated susceptibility to dihydroartemisinin (DHA) from 38 isolates collected in 2017 in Thiès (Senegal) expressed with the Ring-stage Survival Assay (RSA). We explored major and minor variants in the full gene, the main determinant of ART resistance using a targeted-amplicon deep sequencing (TADS) approach.

RESULTS

All samples tested in the RSA were found to be susceptible to DHA. Both non-synonymous mutations K189T and K248R were observed each in one isolate, as major (99%) or minor (5%) variants, respectively.

CONCLUSION

Altogether, investigations combining RSA and TADS are a useful approach for monitoring ART resistance in Africa.