Candidate Markers of Delayed P. Falciparum Clearance After Artemisinin Treatment

A genome-wide association study designed to identify the genetic basis of delayed P. falciparum parasite clearance after treatment with artemisinin was recently published in Proceedings of the National Academies of Sciences. Led by Shannon Takala-Harrison and Chris Plowe (Director of the WWARN Molecular Module) at the University of Maryland School of Medicine, USA, in partnership with collaborators in Thailand, Cambodia, Bangladesh, Austria, Switzerland and the United Kingdom, the World Health Organization-coordinated study included over 300 parasite isolates collected from artesunate clinical trial participants in Bangladesh, northwestern Thailand, and western Cambodia. Of more than 8,000 SNPs that were genotyped, four were found to be significantly associated with delayed parasite clearance. Two of these SNPs, on chromosome 10 and 13, hold promise as useful markers for surveillance of artemisinin resistance and are currently being validated at several sites. A procedure for genotyping these SNPs using PCR-RFLP is available here.