Surveillance of Antimalarial Drug-Resistance Genes in Imported Plasmodium falciparum Isolates From Nigeria in Henan, China, 2012-2019

Malaria remains a major public health issue in Nigeria, and Nigeria is one of the main sources of imported malaria in China. Antimalarial drug resistance is a significant obstacle to the control and prevention of malaria globally. The molecular markers associated with antimalarial drug resistance can provide early warnings about the emergence of resistance. The prevalence of antimalarial drug resistant genes and mutants, including , , , , and , was evaluated among the imported isolates from Nigeria in Henan, China, from 2012 to 2019. Among the 167 imported isolates, the wild-type frequency of , , , , and was 98.7, 63.9, 34.8, 3.1, and 3.1%, respectively. The mutation of was rare, with just two nonsynonymous (S693F and Q613H) and two synonymous mutations (C469C and G496G) identified from four isolates. The prevalence of mutation at codon 74-76 decreased year-by-year, while the prevalence of 86Y also decreased significantly with time. The prevalence of and mutants was high. Combined mutations of and had a high prevalence of the quadruple mutant I R N -G (39.0%), followed by the octal mutant I R N -V A G G S (17.0%). These molecular findings update the known data on antimalarial drug-resistance genes and provide supplemental information for Nigeria.