Country-Wide Surveillance of Molecular Markers of Antimalarial Drug Resistance in Senegal by Use of Positive Malaria Rapid Diagnostic Tests.

Magatte Ndiaye,Michael Alifrangis,Jean Louis Ndiaye,Doudou Sow,Khadime Sylla,Roger Clement Tine,Oumar Gaye,Aminata Collé Lo,Sidsel Nag,Babacar Faye

doi:10.4269/ajtmh.17-0021

Abstract

.In Senegal, antimalarial drugs used in treatment and prevention of malaria are one of the main reasons for the current success in controlling malaria. However, the successful control of malaria is highly dependent on continued effectiveness of these drugs which may be compromised by the spread of drug resistance. Therefore, surveillance of drug resistance in the malaria parasites is essential. The objective of this pilot study was to test the feasibility of routinely sampled malaria rapid diagnostic tests (RDTs) at a national scale to assess the temporal changes in the molecular profiles of antimalarial drug resistance markers of Plasmodium falciparum parasites. Overall, 9,549 positive malaria RDTs were collected from 14 health facilities across the country. A limited random set of RDTs were analyzed regarding Pfcrt gene polymorphisms at codon 72–76. Overall, a high but varied prevalence (> 50%) of the wild-type CVMNK haplotype was observed including a higher CVMNK prevalence in the northern part (75%) compared with the southern part of the country (59%). With caution, the study provides a proof of concept that reuse of discarded P. falciparum positive RDTs can be applied in large-scale surveillance of antimalarial drug resistance.

Highlights

Previous studies on molecular markers of drug resistance have largely relied on extraction of DNA from blood of malariainfected subjects sampled on filter papers
The aim of this study was to pilot test a routine sampling procedure for obtaining used rapid diagnostic tests (RDTs) from sentinel sites across Senegal and measure the prevalence of single nucleotide polymorphisms of one marker of antimalarial drug resistance, the Pfcrt gene related to CQ resistance in a subset of samples
For Pfcrt genotyping at codons 72–76, a nested polymerase chain reaction (PCR), followed by a sequence-specific oligonucleotide probe (SSOP)-enzyme-linked immunosorbent assay (ELISA), was applied as described.[14]

Summary

Use of Positive Malaria Rapid Diagnostic Tests

Magatte Ndiaye,1* Doudou Sow,[1] Sidsel Nag,[2,3] Khadime Sylla,[1] Roger Clement Tine,[1] Jean Louis Ndiaye,[1] Aminata Colle Lo,[1] Oumar Gaye,[1] Babacar Faye,[1] and Michael Alifrangis[2,3]

NDIAYE AND OTHERS

Findings

Richard Toll