Abstract
The spread of Plasmodium falciparum resistant parasites remains one of the major challenges for malaria control and elimination in Sub Saharan Africa. Monitoring of molecular markers conferring resistance to different antimalarials is important to track the spread of resistant parasites and to optimize the therapeutic lifespan of current drugs. This study aimed to evaluate the prevalence of known mutations in the drug resistance genes Pfcrt, Pfmdr1, Pfdhfr and Pfdhps in two different epidemiological settings in Cameroon. Dried blood spots collected in 2018 and 2019 from asymptomatic individuals were used for DNA extraction and then the Plasmodium infection status was determined byPCR. Detection of SNPs was performed by nested PCR followed by allele-specific restriction analysis (ASRA). The prevalence of each genotype was compared between sites using the Chi square and Fisher’s exact tests. A high prevalence of the Pfcrt K76 wild type allele was found in both sites (88.5 and 62.29% respectively; P< 0,0001). The prevalence of Pfmdr1 mutations 86Y and 1246Y was respectively 55.83 and 1.45% in Mfou and 45.87 and 5.97% in Tibati, with significant difference between the studied areas (P<0.0001). Overall, the Pfdhfr triple-mutant genotype (51I/59R/108N) was highly prevalent (> 96%), however no SNP was detected at codon 164. In Pfdhps, the prevalence of the 437G mutation reached (90%) and was at higher frequency in Mfou (P< 0.0001). Overall, the Pfdhps mutations 540E and 581G were less common (0.33 and 3.26%, respectively). The quadruple resistant genotype (Pfdhfr 51I/59R/108N+Pfdhp437G) was found almost 90% of the samples. The wild-type genotype (Pfdhfr N51/C59/S108/164I+Pfdhps A437/K540/A581) was never identified and the sextuple mutant (Pfdhfr 51I/59R/108N+Pfdhp437G/540E/581G), kwon as super resistant appeared in two samples from Tibati. These findings demonstrate declining trends in the prevalence of mutations conferring resistance to 4-aminoquinolines, especially to chloroquine. However, a high level of mutations in P. falciparum genes related to SP resistance was detected and this raises concerns about the future efficacy of IPTp-SP and SMC in Cameroon.
Highlights
Despite global efforts to fight against malaria, the disease remains a serious public health problem
This study assessed the prevalence of antimalarial drug resistance mutations in P. falciparum genes, P. falciparum resistance transporter (Pfcrt), Plasmodium falciparum (Pfmdr1), Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and Plasmodium falciparum dihydropteroate synthase (Pfdhps), in two different regions of Cameroon (Central and Adamawa Regions) more than 15 years after the malaria drug policy have changed from the use of CQ through AQ and SP to Artemisinin-based combination therapy (ACT) in 2004 [8, 53]
In 2012, a household survey conducted in Nigeria found that more than 50% of children suffering from malaria were given CQ even though the national malaria drug policy had changed to ACTs seven years ago [67, 68]
Summary
Despite global efforts to fight against malaria, the disease remains a serious public health problem. Latest estimations from WHO reported 229 million cases of malaria and 409.000 deaths worldwide in 2019, 94% of the cases were recorded in the WHO African Region where nearly 99% of malaria cases were caused by Plasmodium falciparum [1]. Malaria case management has been compromised by parasite resistance to most antimalarial drugs, leading authorities to change guidelines for the treatment of malaria over time [4]. Chloroquine (CQ) resistance in P. falciparum was first detected in Colombia and Cambodia-Thailand border in the late 1950s after decades of heavy use and resistance spread worldwide, reaching Africa in the late 1970s [5]. In 2001, WHO recommended the use of artemisinin-based combination therapies (ACTs) as first line treatment for uncomplicated P. falciparum malaria [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
