Article,
Lack of selection of antimalarial drug resistance markers after intermittent preventive treatment of schoolchildren (IPTsc) against malaria in northeastern Tanzania
Affiliations
- [1] Copenhagen University Hospital [NORA names: Capital Region of Denmark; Hospital; Denmark; Europe, EU; Nordic; OECD];
- [2] University of Copenhagen [NORA names: KU University of Copenhagen; University; Denmark; Europe, EU; Nordic; OECD];
- [3] University of Antwerp [NORA names: Belgium; Europe, EU; OECD];
- [4] National Institute for Medical Research [NORA names: Tanzania; Africa];
- [5] Kenya Medical Research Institute [NORA names: Kenya; Africa]
Abstract
Objective: Intermittent Preventive Treatment of schoolchildren (IPTsc) is recommended by WHO as a strategy to protect against malaria; to explore whether IPTsc with dihydroartemisinin-piperaquine (DP) or artesunate-amodiaquine (ASAQ) cause a selection of molecular markers in Plasmodium falciparum genes associated with resistance in children in seven schools in Tanga region, Tanzania. Methods: SNPs in P. falciparum genes Pfmdr1, Pfexo, Pfkelch13, and Pfcrt and copy number variations in Pfplasmepsin-2 and Pfmdr1 were assessed in samples collected at 12 months (visit 4, n=74) and 20 months (visit 6, n=364) after initiation of IPTsc and compared with the baseline prevalence (n=379). Results: The prevalence of Pfmdr1 N86 and Pfexo 415G was >99% and 0%, respectively without any temporal differences observed. The prevalence of Pfmdr1 184F changed significantly from baseline (52.2%) to visit 6 (64.6%) (χ=6.11, P=0.013), but no differences were observed between the treatment arms (χ=0.05, P=0.98). Finally, only minor differences in the amplification of Pfmdr1 were observed; from 10.2% at baseline to 16.7% at visit 6 (χ=0.98, P=0.32). Conclusions: The IPTsc strategy does not seem to pose a risk for the selection of markers associated with DP or ASAQ resistance. Continuously and timely surveillance of markers of antimalarial drug resistance is recommended.