Background
Malaria remains highly endemic in Cameroon. The rapid emergence and spread of drug resistance was responsible for the change from monotherapies to artemisinin-based combinations. This systematic review and meta-analysis aimed to determine the prevalence and distribution of Plasmodium falciparum drug resistance markers within an evolving efcacy of anti-malarial drugs in Cameroon from January 1998 to August 2020.
Methods
The PRISMA-P and PRISMA statements were adopted in the inclusion of studies on single nucleotide poly‑morphisms (SNPs) of P. falciparum anti-malarial drug resistance genes (Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, Pfatp6, Pfcytb and Pfk13). The heterogeneity of the included studies was evaluated using the Cochran’s Q and I statistics. The random effects model was used as standard in the determination of heterogeneity between studies.
Results
Out of the 902 records screened, 48 studies were included in this aggregated meta-analysis of molecular data. A total of 18,706 SNPs of the anti-malarial drug resistance genes were genotyped from 47,382 samples which yielded a pooled prevalence of 35.4 percent (95 percent CI 29.1–42.3 percent). Between 1998 and 2020, there was signifcant decline
(P<0.0001 for all) in key mutants including Pfcrt 76 T (79.9 percent – 43.0 percent), Pfmdr1 86Y (82.7 percent – 30.5 percent), Pfdhfr 51I (72.2 percent – 66.9 percent), Pfdhfr 59R (76.5 percent – 67.8 percent), Pfdhfr 108 N (80.8 percent –67.6 percent). The only exception was Pfdhps 437G which increased over time (30.4 percent – 46.9 percent, P<0.0001) and Pfdhps 540E that remained largely unchanged (0.0 percent – 0.4 percent, P=0.201). Exploring mutant haplotypes, the study observed a signifcant increase in the prevalence of Pfcrt CVIET mixed quintuple haplotype from 57.1 percent in 1998 to 57.9 percent in 2020 (P<0.0001). In addition, within the same study period, there was no signifcant change in the triple Pfdhfr IRN mutant haplotype (66.2 percent – 67.3 percent, P=0.427). The Pfk13 amino acid poly‑morphisms associated with artemisinin resistance were not detected.
Published in Malaria Journal
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