Polymorphisms in drug resistance genes of Plasmodium falciparum imported into Jiangxi, 2017−2020

  Objective  To understand the prevalence of drug resistance of imported Plasmodium falciparum in Jiangxi province from 2017 to 2020 and provide technical support for clinical drug use.

  Methods  From 2017 to 2020, blood samples were collected from imported falciparum malaria cases in Jiangxi, the drug resistant genes of Plasmodium falciparum were amplified using a nested PCR assay, followed by DNA sequencing, and the sequences were aligned.

  Results  A total of 85 blood samples of imported falciparum malaria cases were collected, all the cases were imported from Africa. The mutation rates of chloroquine resistance transporter gene (pfcrt) and multidrug resistance gene 1 (pfmdr1) of Plasmodium falciparum were low (16.67%, 14/84 and 1.18%, 1/85), the mutation rate of dihydrofolate reductase gene (pfdhfr) was high (96.39%, 80/83), and no mutation of kelch spirochete gene (K13) was found by sequencing analysis.

  Conclusion  In recent years, imported cases of falciparum malaria in Jiangxi were all from Africa, and the resistance of Plasmodium falciparum to chloroquine was low. Based on the clinical experiments, the treatment of imported falciparum malaria cases from Africa with chloroquine in combination of other drugs can be considered. The resistance to pyrimidine was high, and no artemisinin resistant strain was found. However, due to the impact of COVID-19 epidemic in recent 2 years, it was impossible to conclude that there was no artemisinin resistant strains in our province based on the small sample size, so it is necessary to continue the surveillance.