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 efficacy 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 polymorphisms (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 I2 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% (95% CI 29.1–42.3%). Between 1998 and 2020, there was significant decline (P < 0.0001 for all) in key mutants including Pfcrt 76 T (79.9%-43.0%), Pfmdr1 86Y (82.7%-30.5%), Pfdhfr 51I (72.2%-66.9%), Pfdhfr 59R (76.5%-67.8%), Pfdhfr 108 N (80.8%-67.6%). The only exception was Pfdhps 437G which increased over time (30.4%-46.9%, P < 0.0001) and Pfdhps 540E that remained largely unchanged (0.0%-0.4%, P = 0.201). Exploring mutant haplotypes, the study observed a significant increase in the prevalence of Pfcrt CVIET mixed quintuple haplotype from 57.1% in 1998 to 57.9% in 2020 (P < 0.0001). In addition, within the same study period, there was no significant change in the triple Pfdhfr IRN mutant haplotype (66.2% to 67.3%, P = 0.427). The Pfk13 amino acid polymorphisms associated with artemisinin resistance were not detected. Conclusions This review reported an overall decline in the prevalence of P. falciparum gene mutations conferring resistance to 4-aminoquinolines and amino alcohols for a period over two decades. Resistance to artemisinins measured by the presence of SNPs in the Pfk13 gene does not seem to be a problem in Cameroon. Systematic review registration PROSPERO CRD42020162620

Malaria is still a threat to public health as it remains the first endemic disease in the world. It is a pervasive parasitic disease in tropical and subtropical regions where asymptomatic malaria infection among humans serves as a significant reservoir for transmission. A rapid and correct diagnosis is considered to be an important strategy in the control of the disease especially in children, who are the most vulnerable group. This study assessed the prevalence of asymptomatic malaria in children at the Nkolbisson health area in Yaoundé, Cameroon. A cross-sectional study design and a convenience sampling plan were used. A total of 127 participants were recruited after informed and signed consent from parents and/or guardians. Blood samples were collected by finger-pricking and venipuncture from children aged 6 months to 10 years and then screened for asymptomatic parasitemia by a rapid diagnostic test (RDT), light microscopy (LM) staining with Giemsa and 18S rRNA polymerase chain reaction (PCR) for speciation. The data were analyzed using SPSS version 20 software. The study identified 85 children who were positive from the PCR, 95 positive from the RDT and 71 from the LM, revealing a malaria prevalence of 66.9%, 74.8% and 55.9%, respectively. The prevalence was not observed to be dependent on the sex and age group of the participants. Plasmodium falciparum was the predominant species followed by Plasmodium malariae and then Plasmodium ovale. The RDT and LM had the same sensitivity (90.6%) with a slight difference in their specificity (RDT: 57.1%; LM: 54.8%). The RDT also demonstrated higher positive and negative predictive values compared with those of the LM.

Background: Cameroon remains a country faced with high malaria burden despite enormous efforts made in the control of the disease. The rapid development and dispersal of mutations associated with anti-malarial drug resistance influenced policy changes from the use of chloroquine, amodiaquine and sulphadoxine-pyrimethamine to the adoption of artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated falciparum malaria. However, the impact of drug policy changes on the evolution of molecular markers of Plasmodium falciparum resistance in Cameroon has not been completely understood. Hence, this systematic review and meta-analysis aims to determine the prevalence and distribution of P. falciparum drug resistance markers within an evolving efficacy of anti-malarial drugs in Cameroon from 1998 to present.Methods: The PRISMA, PRISMA-P and STREGA statements will be adopted in the quality assessments of studies to be included in this review. The electronic databases of Medline via Pubmed, EMBASE, Google Scholar and Science Direct will be searched by two independent researchers using different MeSH terms and Boolean operators (AND, OR). More so, unpublished data that will be sourced from academic libraries will also be extracted. Quantitative syntheses will be done using the “metaphor” and “meta” commands in the R statistical software package version 3.5.2. Heterogeneity will be assessed using the Cochran’s Q and I2 statistics. The random effects model will be used as standard in the determination of heterogeneity between studies. Discussion: The primary outcome of this review is to identify and describe molecular markers conferring drug resistance in Plasmodium falciparum parasites that have been circulating for a period of over 20 years in Cameroon. This review will be able to pool data from previously published and unpublished studies on anti-malarial drug resistance gene mutations. This will provide evidence to support the continuous use of ACTs in the treatment of uncomplicated P. falciparum malaria. Furthermore, data generated from the study will be used as baseline information for the design and adoption of a robust anti-malarial drug resistance surveillance system nationwide which is inexistent. Systematic review registration: PROSPERO CRD42020162620