Effect of mass dihydroartemisinin-piperaquine administration in southern Mozambique on the carriage of molecular markers of antimalarial resistance

Background Mass drug administration (MDA) can rapidly reduce the burden ofPlasmodium falciparum(Pf). However, concerns remain about its contribution to select for antimalarial drug resistance. Methods We used Sanger sequencing and real-time PCR to determine the proportion of molecular markers associated with antimalarial resistance (k13,pfpm2,pfmdr1 and pfcrt) inPfisolates collected before (n = 99) and after (n = 112) the implementation of two monthly MDA rounds with dihydroartemisinin-piperaquine (DHAp) for two consecutive years in Magude district of Southern Mozambique. Results None of thek13polymorphisms associated with artemisinin resistance were observed in thePfisolates analyzed. The proportion ofPfisolates with multiple copies ofpfpm2, an amplification associated with piperaquine resistance, was similar in pre- (4.9%) and post-MDA groups (3.4%; p = 1.000). No statistically significant differences were observed between pre- and post-MDA groups in the proportion ofPfisolates neither with mutations inpfcrtandpfmdr1genes, nor with the carriage ofpfmdr1multiple copies (p>0.05). Conclusions This study does not show any evidence of increased frequency of molecular makers of antimalarial resistance after MDA with DHAp in southern Mozambique where markers of antimalarial resistance were absent or low at the beginning of the intervention.