Evolution of Plasmodium falciparum antimalarial drug resistance markers post-adoption of artemisinin-based combination therapies in Yaounde, Cameroon.

Objectives: This study aimed to investigate the evolution of Plasmodium falciparum antimalarial drug resistance markers by comparing the pre- and post-adoption of artemisinin-based combination therapies (ACTs) in Yaounde, Cameroon.

Methods: The molecular characterization of known antimalarial drug resistance markers (Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and Pfk13) in P. falciparum-positive samples collected in 2014 and 2019-2020 was achieved using nested polymerase chain reaction, followed by targeted amplicon deep sequencing on the Illumina MiSeq platform.

Discrete Survival Model Analysis of Response to Artemisinin-Based Combination Therapies among Children in Regions of Varying Malaria Transmission in Cameroon.

The need to monitor changes in parasite clearance following treatment with artemisinin-based combination therapies (ACTs) is important in the containment of drug resistance. This study aimed to model response to ACTs among children in two different transmission settings (Mutengene and Garoua) in Cameroon. Using the step function, a discrete-time survival model was fitted with all the covariates included that might play a role in parasite clearance.

Drug resistance markers within an evolving efficacy of anti-malarial drugs in Cameroon: a systematic review and meta-analysis (1998-2020).

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.

Effects of Drug Policy Changes on Evolution of Molecular Markers of Resistance to Chloroquine, Amodiaquine, and Sulphadoxine-Pyrimethamine in the South West Region of Cameroon.

Background: As a result of the spread of parasites resistant to antimalarial drugs, Malaria treatment guidelines in Cameroon evolved from nonartemisinin monotherapy to artemisinin-based combination therapy. The aim of this study was to assess the effect of these therapy changes on the prevalence of molecular markers of resistance from 2003 to 2013 in Mutengene, Cameroon.

Methodology: Dry blood samples (collected in 2003-2005 and 2009-2013) were used for parasite DNA extraction.

Investigation of the association between the TCF7L2 rs7903146 (C/T) gene polymorphism and obesity in a Cameroonian population: a pilot study.

Objective: This study aimed at investigating the association between the rs7903146 (C/T) polymorphism of the TCF7L2 gene with obesity in a Cameroonian population.

Method: This was a case-control pilot study including 61 obese and 61 non-obese Cameroonian adults. Anthropometric indices of obesity, blood pressure, fasting blood glucose, and blood lipids were measured.

The Pro12Ala polymorphism in the PPAR-γ2 gene is not associated to obesity and type 2 diabetes mellitus in a Cameroonian population.

Background: Peroxisome proliferator-activated receptor gamma 2 (PPAR-γ2) is a transcription factor with a key role in adipocyte differentiation, lipid storage and glucose homeostasis. The Ala allele of the common Pro12Ala polymorphism in the isoform PPAR-γ2 is at the center of many controversies because in some populations, it has been observed to be associated with T2DM or obesity but, not in others. The aim of this study was to investigate the association of Pro12Ala polymorphism in the PPAR-γ2 gene with susceptibility to obesity or T2DM in a Cameroonian population.

Association between the rs12255372 variant of the TCF7L2 gene and obesity in a Cameroonian population.

Background: The transcription factor 7-like 2 (TCF7L2) is one of the genes that have been identified as possible determinants of diabetes which is associated with obesity. Data on the genetic causes of obesity in sub-Saharan African populations are very scares. The aim of this study was to assess the association between the transcription factor 7-like 2 (TCF7L2) gene polymorphism (rs12255372 G/T) and obesity and weight-related traits in a Cameroonian population.

Association between the TCF7L2 rs12255372 (G/T) gene polymorphism and type 2 diabetes mellitus in a Cameroonian population: a pilot study.

Background: To study the relationship between the rs12255372 (G/T) polymorphism of the transcription factor 7-like 2 (TCF7L2) and type 2 diabetes mellitus (T2DM) in a Cameroonian population.

Methods: This case-control study included 60 T2DM patients and 60 healthy normoglycemic controls, all unrelated and of Cameroonian origin, aged above 40 years (range 40-87). The Restriction Fragment Length Polymorphism - Polymerase Chain Reaction (RFLP-PCR) was used for genotyping.

Contribution of the TCF7L2 rs7903146 (C/T) gene polymorphism to the susceptibility to type 2 diabetes mellitus in Cameroon.

Background: Data on the genetic variants for type 2 diabetes mellitus (T2DM) in sub-Saharan African populations are very scarce. This study aimed to investigate the association of transcription factor 7-like (TCF7L2) with T2DM in a Cameroonian population and explore possible genotype-phenotype correlation.

Methods: This is a case-control study involving 37 T2DM patients and 37 non-diabetic volunteers of Cameroonian ethnicity aged 40 years old and above.

Host candidate gene polymorphisms and associated clearance of P. falciparum amodiaquine and fansidar resistance mutants in children less than 5 years in Cameroon.

Background: In this post-hoc analysis, we determined the influence of single nucleotide polymorphisms in host candidate immune genes on the outcome of drug resistant malaria in Cameroon.

Methods: Human DNA from 760 patients from a previous clinical trial was subjected to mass spectrometry-based single nucleotide polymorphism (SNP) genotyping. Allele frequencies of candidate immune genes were calculated for 62 SNPs on 17 human chromosomes for their possible involvement in clearance of drug-resistant parasites with the triple mutations of pfcrt76T, pfmdr86Y, and pfmdr1246Y (TY) and pfdhfr51I, pfdhfr59R, pfdhfr108N, and pfdhps437G (IRNG) which were determined by dotblot or PCR-restriction analysis.

Host candidate gene polymorphisms and clearance of drug-resistant Plasmodium falciparum parasites.

Background: Resistance to anti-malarial drugs is a widespread problem for control programmes for this devastating disease. Molecular tests are available for many anti-malarial drugs and are useful tools for the surveillance of drug resistance. However, the correlation of treatment outcome and molecular tests with particular parasite markers is not perfect, due in part to individuals who are able to clear genotypically drug-resistant parasites.

Efficacy of amodiaquine, sulphadoxine-pyrimethamine and their combination for the treatment of uncomplicated Plasmodium falciparum malaria in children in Cameroon at the time of policy change to artemisinin-based combination therapy.

Background: The efficacy of amodiaquine (AQ), sulphadoxine-pyrimethamine (SP) and the combination of SP+AQ in the treatment of Cameroonian children with clinical malaria was investigated. The prevalence of molecular markers for resistance to these drugs was studied to set the baseline for surveillance of their evolution with time.

Methods: Seven hundred and sixty children aged 6-59 months with uncomplicated falciparum malaria were studied in three ecologically different regions of Cameroon - Mutengene (littoral equatorial forest), Yaoundé (forest-savannah mosaic) and Garoua (guinea-savannah).