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

Prevalence of antimalaria drug resistance-conferring mutations associated with sulphadoxine-pyrimethamineine-resistant Plasmodium falciparum in East Africa: a systematic review and meta-analysis

BACKGROUND

The emergence and spread of drug resistance to antimalarial drugs pose a severe threat to effective malaria control and treatment. Although sulfadoxine-pyrimethamine resistance is well-documented, it is still the drug of choice for treating intermittent resistance. Molecular markers play a crucial role in tracking and understanding the prevalence of antimalarial drug resistance. Currently, there is insufficient information on the prevalence of molecular markers associated with sulfadoxine-pyrimethamine resistance in P. falciparum.

OBJECTIVE

This systematic review and meta-analysis aimed to determine the pooled prevalence of antimalaria drug resistance-conferring markers associated with sulphadoxine-pyrimethamineine in Plasmodium falciparum in East Africa.

METHODS

Systematic searche was performed to retrieve articles from PubMed, Scopus, Science Direct databases, and Google Scholar search engine. Sixteen potential studies that provided important data on markers for sulphadoxine-pyrimethamineine resistance in Plasmodium falciparum were systematically reviewed and analyzed. Nine antimalarial drug resistance markers responsible for sulphadoxine-pyrimethamineine resistance in Plasmodium falciparum were extracted separately into Microsoft Excel and analyzed using STATA 17.0. The inverse of variance was done to evaluate heterogeneity across studies. A funnel plot was used to determine the presence of publication bias. A trim-and-fill-meta-analysis was carried out to generate a bias-adjusted effect estimate. A random effect model was used to determine the pooled prevalence of markers responsible for sulphadoxine-pyrimethamineine resistance. Subgroup analysis was performed based on country and year of publication.

RESULTS

A total of 16 studies were included for this systematic review and meta-analysis.The molecular markers like dhfr (N51I, C59R, S108N, 108N, 59R, and I164L), and dhps (A437G, K540E, & 540E) were selected for meta-analysis. From this meta-analysis, the pooled prevalence of dhfr N51I, dhfr C59R, dhfr S108N, dhfr 108N, dhfr 59R, and dhfr I164L was 88.6%, 85.3%, 89.6%, 92.2%, 71.5%, and 3.9%, respectively. Likewise, the aggregated prevalence of dhps A437G, dhps K540E, and dhps 540E was 90.2%, 80.9%, and 91.5%, respectively. The subgroup analysis based on year of publication showed that the pooled prevalence of dhfr N51I, dhfr C59R, dhfr S108N, dhps A437G, and dhps K540E, in studies conducted 2014-2018 was 97.11%, 90.57%, 96.45%, 90.89%, and 89.45%, respectively, while it was 82.03%, 81.78%, 85.12%, 89.24%, and 73.98%, respectively, in studies conducted 2019-2023. On the other hand, country-based analysis showed that the pooled prevalence of dhfr N51I, dhfr C59R, dhfr S108N, dhps A437G, and dhps K540E, in Kenya was 85.88%, 84.02%, 86.56%, 90.7%, and 77.55%, respectively.

CONCLUSIONS

This systematic review and meta-analysis reveal a high prevalence of drug resistance markers  associated with sulphadoxine-pyrimethamine resistance in Plasmodium falciparum across the East African region. This underscores the significant challenges in managing malaria infections caused by Plasmodium falciparum in the region. Therefore, regular monitoring, identification, and limiting of drug-resistance markers and drug-resistant P. falciparum strains must be sustained to ensure the effectiveness of malaria treatment.

Prevalence of molecular markers of chloroquine resistance in malaria parasites in East Africa: A systematic review and meta-analysis

BACKGROUND

Malaria is a serious global public health problem, which is caused by genus Plasmodium. Resistance of the human malaria parasite to antimalarial drugs is a public health concern in malaria endemic countries. Chloroquine is resistant for both P. vivax and P. falciparum. Chloroquine resistance is understood throughout all of Africa's P. falciparum endemic regions. Molecular markers play a crucial role in tracking and understanding the prevalence of antimalarial drug resistance. Currently, there is inadequate information on the prevalence of molecular markers of chloroquine resistance in malaria parasites.

OBJECTIVE

This systematic review and meta-analysis aimed to determine the pooled prevalence of molecular markers of chloroquine resistance in malaria parasites in East Africa.

METHODS

Systematic search was performed to retrieve articles from PubMed, Scopus, Science Direct, and the Google Scholar search engine. Twenty potential studies that provided important data on markers of chloroquine resistance in malaria parasites were systematically reviewed and analyzed. Five antimalarial drug resistance markers of chloroquine resistance were extracted separately into Microsoft Excel and analyzed using STATA 17.0. The Inverse of variance (I2) was done to evaluate heterogeneity across studies. The funnel plot and the Egger's test were used to determine the existence or absence of publication bias. A trim-and-fill meta-analysis was carried out to generate a bias-adjusted effect estimate. A random effect model was used to determine the pooled prevalence of molecular markers associated with chloroquine resistance in malaria parasites. Subgroup analysis was performed based on country and year of publication.

RESULTS

A total of 20 studies were included for this systematic review and meta-analysis. The molecular markers like K76T, 76T, N86Y, Y184F, and 86Y were selected for meta-analysis. From this meta-analysis, the pooled prevalence of K76T, 76T, N86Y, Y184F, and 86Y was 34.5%, 47.3%, 43.8%, 58.3%, and 29.2%, respectively. After adjusting for publication bias, the estimated pooled prevalence of K76T, 76T, N86Y, Y184F, and 86Y were 34.5%, 47.3%, 43.8%, 58.3%, and 29.2%, respectively. Meta-analysis showed a significant difference in all molecular marker prevalence like K76T and 86Y among studies on year of publication except 76T, N86Y, and Y184F. In addition, the meta-analysis showed a significant difference in all molecular marker prevalence like K76T, 76T, N86Y, Y184F, and 86Y among studies at the country level.

CONCLUSIONS

The findings of this systematic review and meta-analysis concerning the molecular markers of chloroquine resistance of malaria parasites in East Africa revealed a significant prevalence of antimalarial drug resistance markers of chloroquine. As a result, continued surveillance and monitoring of the prevalence of molecular markers of chloroquine resistance, identification and limitation of drug-resistant malaria parasite strains, and development of new antimalarial treatments are required to guide malaria treatment policies, interventions, control, and elimination of malaria worldwide.

Prevalence and genetic diversity of polymorphisms in pfcrt, pfdhfr-ts and pfk13 propeller genes of Plasmodium falciparum in southern Côte d'Ivoire

Background

Plasmodium falciparum has developed resistance to almost all the antimalarial drugs currently in use. This resistance has been and remains one of the greatest threats to the control and elimination of malaria. The use of molecular markers of resistance to monitor the emergence and spread of antimalarial drug-resistant parasite strains has proved highly effective. The aim of this study was to analyse the polymorphism of the pfcrt, pfdhfr-ts and pfK13 propeller genes for resistance in P. falciparum to chloroquine (CQ), pyrimethamine and artemisinin-based combination therapies (ACTs) in three sites in southern Côte d'Ivoire.

Methodology

Blood samples were collected in Anonkoua-kouté, Port-Bouët, and Ayamé from 94 patients with microscopically confirmed uncomplicated P. falciparum malaria. These patients, aged over 2 years, gave their informed consent prior to blood sampling. P. falciparum genomic DNA extracted from these samples was amplified by nested PCR using primers specific to the pfcrt, pfdhfr-ts and Pfk13 propeller genes. The amplification products were sequenced using the Sanger method. After sequencing, the prevalence of pfcrt (M74I, N75E, K76T), pfdhfr (N51I, C59R, S108N) and pfk13 propeller (Y493H, R539T, I543T, C580Y, M476I and R561H) mutations confirmed to be involved in P. falciparum resistance to CQ, pyrimethamine and ACTs, respectively was determined. Data were analysed using R statistical software, version 3.2.2.

Results

For all three study sites, 93 (93/94, i.e. 98.94%), 86 (86/94, i.e. 94.49%) and 74 (74/94, i.e. 78.72%) DNA fragments from patient isolates were successfully amplified for the Pfk13 propeller, pfdhfr-ts and pfcrt genes, respectively. Of the successfully amplified fragments, 93 (93/93, i.e. 100%), 81 (81/86, i.e. 94.18%) and 64 (64/74, i.e. 86.48%) were successfully sequenced for the pfk13 propeller, pfdhfr-ts and pfcrt genes, respectively. Sequence analysis indicated that S108N mutations in the pfdhfr gene and K76T mutations in the pfcrt gene were observed in 74.07% (60/81) and 15.62% (10/64) respectively. Analysis of the k13 propeller gene also showed a predominance of the YRICMR allelic form representing the sensitive haplotype (72/93, i.e. 78.49%).

Conclusions

More than a decade after the abandonment of the use of CQ and the adoption of sulfadoxinepyrimethamine (SP) as intermittent preventive treatment (IPT) for pregnant women, the prevalence of alleles associated with CQ chemoresistance, represented by the K76T mutation in the pfcrt gene, fell, while that of alleles associated with pyrimethamine chemoresistance, represented by the S108N mutation in the pfdhfr-ts gene, increased in Anonkoua-Kouté, Port-Bouët and Ayamé. No mutations in mutant alleles of the K13 propeller gene conferring resistance to artemisinin derivatives were observed at any of the study sites. The study thus showed that the ACTs used for first-line treatment of malaria in Côte d'Ivoire are still effective.

Mapping Antimalarial Drug Resistance in Mozambique: A Systematic Review of Plasmodium falciparum Genetic Markers Post-ACT Implementation

Malaria continues to be a significant public health burden in many tropical and subtropical regions. Mozambique ranks among the top countries affected by malaria, where it is a leading cause of morbidity and mortality, accounting for 29% of all hospital deaths in the general population and 42% of deaths amongst children under five. This review presents a comparative analysis of data on five critical genes associated with antimalarial drug resistance: pfmdr1, pfcrt, pfk13, pfdhfr, and pfdhps, along with the copy number variation (CNV) in genes pfmdr1 and pfpm2/3. These are genes associated with parasite response to antimalarials currently used to treat uncomplicated P. falciparum malaria in Mozambique. The review synthesizes data collected from published studies conducted in Mozambique after the introduction of artemisinin-based combination therapies (ACTs) (2006) up to June 2024, highlighting the presence or absence of mutations in these genes across Mozambique. We aimed at mapping the prevalence and distribution of these molecular markers across the country in order to contribute to the development of targeted interventions to sustain the efficacy of malaria treatments in Mozambique. Four databases were used to access the articles: PubMed, Science Direct, Scopus, and Google scholar. The search strategy identified 132 studies addressing malaria and antimalarial resistance. Of these, 112 were excluded for various reasons, leaving 20 studies to be included in this review. Children and pregnant women represent the majority of target groups in studies on all types of antimalarials. Most studies (87.5%) were conducted in the provinces of Maputo and Gaza. The primary alleles reported were pfcrt CVMNK, and in the most recent data, its wild-type form was found in the majority of patients. A low prevalence of mutations in the pfk13 gene was identified reflecting the effectiveness of ACTs. In pfk13, only mutation A578S was reported in Niassa and Tete. CNVs were observed in studies carried out in the south of Mozambique, with a frequency of 1.1-5.1% for pfmdr1 and a frequency of 1.1-3.4% for pfpm2. This review indicates that molecular markers linked to malaria resistance show considerable variation across provinces in Mozambique, with most up-to-date data accessible for Maputo and Gaza. In contrast, provinces such as Zambezia and Inhambane have limited data on several genes, while Nampula lacks data on all drug resistance markers.

Epidemiology of malaria in Gabon: A systematic review and meta-analysis from 1980 to 2023

The objective of this were conducted to elucidate spatiotemporal variations in malaria epidemiology in Gabon since 1980. For that, five databases, were used to collect and identify all studies published between 1980 and 2023 on malaria prevalence, antimalarial drug resistance, markers of antimalarial drug resistance and insecticide resistance marker. The findings suggest that Gabon continues to face malaria as an urgent public health problem, with persistently high prevalence rates. Markers of resistance to CQ persist despite its withdrawal, and markers of resistance to SP have emerged with a high frequency, reaching 100 %, while ACTs remain effective. Also, recent studies have identified markers of resistance to the insecticides Kdr-w and Kdr-e at frequencies ranging from 25 % to 100 %. Ace1R mutation was reported with a frequency of 0.4 %. In conclusion, the efficacy of ACTs remains above the threshold recommended by the WHO. Organo-phosphates and carbamates could provide an alternative for vector control.

Plasmodium falciparum dhps and dhfr markers of resistance to sulfadoxine-pyrimethamine five years (2016-2020) after the implementation of seasonal malaria chemoprevention in Cameroon

Background

Antimalarial drug resistance is a major challenge in the fight against malaria. Cameroon implemented seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine (SPAQ) to over 1.5 million children aged 3-59 months from 2016, raising concerns whether drug pressure may lead to a selection of known parasite resistance mutations. This study aimed at assessing the profiles of plasmodium falciparum dihydrofolate reductase (DHFR) and plasmodium falciparum dihydropteroate synthase (DHPS) gene mutations that encode enzyme targeting SP before and 5 years after the introduction of SMC in the northern part of Cameroon.

Methods

Dried blood spots were prepared from symptomatic P. falciparum-positive children prior to SPAQ administration in 2016 and after the SMC round of 2020. DNA was extracted using the Chelex-100 method, and dhfr and dhps mutations were determined after a nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique and agarose gel electrophoresis.

Results

405 children with acute uncomplicated malaria were recruited. Of 405 samples, 201/405 (49.63%) were collected in 2016 and 204/405 (50.37%) were collected in 2020. High levels of mutant alleles S108N, C59R, N51I of dhfr were obtained both in 2016 and 2020 (174 (100%), 166 (95.4%), 131 (75.3%)); (140 (99.4%), 131 (92.2%), 114 (80.3%)) while the frequency of dhps mutant alleles in the A437G and K540E loci stood at 93 (51.9%) and 6 (3.4%) in 2016 and 73 (52.5%) and 4 (2.8%) in 2020, respectively. The quintuple resistant haplotype IRNGE was found in two (1.1%) and one (0.7%) in 2016 and 2020, respectively. No significant difference was observed in the frequency of the studied mutations between the two time points, although we noted a rise in the resistance conferring haplotype IRNG in 2020.

Conclusions

Continuous monitoring is recommended to preempt the widespread occurrence of high-grade resistance bearing parasites in the northern regions of Cameroon.

First Insight into Drug Resistance Genetic Markers, Glucose-6-Phosphate Dehydrogenase and Phylogenetic Patterns of Misdiagnosed Plasmodium vivax Malaria in Far North Region, Cameroon

Plasmodium falciparum (Pf) is the predominant malaria species in Africa, but growing rates of non-falciparum species such as P. vivax (Pv) have been reported recently. This study aimed at characterizing drug resistance genes, glucose-6-phosphate dehydrogenase gene (G6PD), and phylogenetic patterns of a Pv + Pf co-infection misdiagnosed as a Pf mono-infection in the Far North region of Cameroon. Only one non-synonymous mutation in the pvdhps gene A383G was found. Pv drug resistance gene sequences were phylogenetically closer to the reference SAL-I strain and isolates from Southeast Asia and Western Pacific countries. Analyzing co-infecting Pf revealed no resistance mutations in Pfmdr1 and Pfk13 genes, but mutations in Pfcrt (C72V73I74E75T76) and Pfdhfr-Pfdhps genes (A16C50I51R59N108L164 - A436A437K540G581S613) were observed. No G6PD deficiency-related mutations were found. This is first study from Cameroon reporting presence of putative drug resistance mutations in Pv infections, especially in the pvdhps gene, and also outlined the absence of a G6PD-deficiency trait in patients.

Nationwide spatiotemporal drug resistance genetic profiling from over three decades in Indian Plasmodium falciparum and Plasmodium vivax isolates

BACKGROUND

Drug resistance is a serious impediment to efficient control and elimination of malaria in endemic areas.

METHODS

This study aimed at analysing the genetic profile of molecular drug resistance in Plasmodium falciparum and Plasmodium vivax parasites from India over a ~ 30-year period (1993-2019). Blood samples of P. falciparum and/or P. vivax-infected patients were collected from 14 regions across India. Plasmodial genome was extracted and used for PCR amplification and sequencing of drug resistance genes in P. falciparum (crt, dhps, dhfr, mdr1, k13) and P. vivax (crt-o, dhps, dhfr, mdr1, k12) field isolates.

RESULTS

The double mutant pfcrt SVMNT was highly predominant across the country over three decades, with restricted presence of triple mutant CVIET from Maharashtra in 2012. High rates of pfdhfr-pfdhps quadruple mutants were observed with marginal presence of "fully resistant" quintuple mutant ACIRNI-ISGEAA. Also, resistant pfdhfr and pfdhps haplotype has significantly increased in Delhi between 1994 and 2010. For pfmdr1, only 86Y and 184F mutations were present while no pfk13 mutations associated with artemisinin resistance were observed. Regarding P. vivax isolates, the pvcrt-o K10 "AAG" insertion was absent in all samples collected from Delhi in 2017. Pvdhps double mutant SGNAV was found only in Goa samples of year 2008 for the first time. The pvmdr1 908L, 958M and 1076L mutations were highly prevalent in Delhi and Haryana between 2015 and 2019 at complete fixation. One nonsynonymous novel pvk12 polymorphism was identified (K264R) in Goa.

CONCLUSIONS

These findings support continuous surveillance and characterization of P. falciparum and P. vivax populations as proxy for effectiveness of anti-malarial drugs in India, especially for independent emergence of artemisinin drug resistance as recently seen in Africa.

Effectiveness of Intermittent Preventive Treatment with Sulfadoxine-Pyrimethamine in Pregnancy: Low Coverage and High Prevalence of Plasmodium falciparum dhfr-dhps Quintuple Mutants as Major Challenges in Douala, an Urban Setting in Cameroon

Intermittent preventive treatment in pregnancy with sulfadoxine and pyrimethamine (IPTp-SP) is a key component in the malaria control strategy implemented in Africa. The aim of this study was to determine IPTp-SP adherence and coverage, and the impact on maternal infection and birth outcomes in the context of widespread SP resistance in the city of Douala, Cameroon. Clinical and demographic information were documented among 888 pregnant women attending 3 health facilities, from the antenatal care visit to delivery. Positive samples were genotyped for P. falciparum gene (dhfr, dhps, and k13) mutations. The overall IPTp-SP coverage (≥three doses) was 17.5%, and 5.1% received no dose. P. falciparum prevalence was 16%, with a predominance of submicroscopic infections (89.3%). Malaria infection was significantly associated with locality and history of malaria, and it was reduced among women using indoor residual spraying. Optimal doses of IPTp-SP were significantly associated with reduced infection among newborns and women (secundiparous and multiparous), but there was no impact of IPTp-SP on the newborn bodyweight. Pfdhfr-Pfdhps quintuple mutants were over-represented (IRNI-FGKAA, IRNI-AGKAA), and sextuple mutants (IRNI-AGKAS, IRNI-FGEAA, IRNI-AGKGS) were also reported. The Pfk13 gene mutations associated with artemisinin resistance were not detected. This study highlights the role of ANC in achieving optimal SP coverage in pregnant women, the mitigated impact of IPTp-SP on malaria outcomes, and the high prevalence of multiple SP-resistant P. falciparum parasites in the city of Douala that could compromise the efficacy of IPTp-SP.

High vector diversity and malaria transmission dynamics in five sentinel sites in Cameroon

BACKGROUND

Malaria remains one of the main causes of morbidity and mortality in Cameroon. To inform vector control intervention decision making, malaria vector surveillance was conducted monthly from October 2018 to September 2020 in five selected sentinel sites (Gounougou and Simatou in the North, and Bonabéri, Mangoum and Nyabessang in the South).

METHODS

Human landing catches (HLCs), U.S. Centers for Disease Control and Prevention (CDC) light traps, and pyrethrum spray catches (PSCs) were used to assess vector density, species composition, human biting rate (HBR), endophagic index, indoor resting density (IRD), parity, sporozoite infection rates, entomological inoculation rate (EIR), and Anopheles vectorial capacity.

RESULTS

A total of 139,322 Anopheles mosquitoes from 18 species (or 21 including identified sub-species) were collected across all sites. Out of the 18 species, 12 were malaria vectors including Anopheles gambiae sensu lato (s.l.), Anopheles funestus s.l.., Anopheles nili, Anopheles moucheti, Anopheles paludis, Anopheles demeilloni, Anopheles. pharoensis, Anopheles ziemanni, Anopheles multicinctus, Anopheles tenebrosus, Anopheles rufipes, and Anopheles marshallii. Anopheles gambiae s.l. remains the major malaria vector (71% of the total Anopheles) collected, though An. moucheti and An. paludis had the highest sporozoite rates in Nyabessang. The mean indoor HBR of Anopheles ranged from 11.0 bites/human/night (b/h/n) in Bonabéri to 104.0 b/h/n in Simatou, while outdoors, it varied from 24.2 b/h/n in Mangoum to 98.7 b/h/n in Simatou. Anopheles gambiae s.l. and An. moucheti were actively biting until at least 8:00 a.m. The mean Anopheles IRD was 17.1 females/room, and the parity rate was 68.9%. The mean EIRs for each site were 55.4 infective bites/human/month (ib/h/m) in Gounougou, 99.0 ib/h/m in Simatou, 51.2 ib/h/m in Mangoum, 24.4 ib/h/m in Nyabessang, and 18.1 ib/h/m in Bonabéri. Anopheles gambiae s.l. was confirmed as the main malaria vector with the highest vectorial capacity in all sites based on sporozoite rate, except in Nyabessang.

CONCLUSION

These findings highlight the high malaria transmission occurring in Cameroon and will support the National Malaria Control Program to design evidence-based malaria vector control strategies, and deployment of effective and integrated vector control interventions to reduce malaria transmission and burden in Cameroon, where several Anopheles species could potentially maintain year-round transmission.

The Rare, the Best: Spread of Antimalarial-Resistant Plasmodium falciparum Parasites by Anopheles Mosquito Vectors

The emergence of resistance to antimalarials has prompted the steady switch to novel therapies for decades. Withdrawal of antimalarials, such as chloroquine in sub-Saharan Africa in the late 1990s, led to rapid declines in the prevalence of resistance markers after a few years, raising the possibility of reintroducing them for malaria treatment. Here, we provide evidence that the mosquito vector plays a crucial role in maintaining parasite genetic diversity. We followed the transmission dynamics of Plasmodium falciparum parasites through its vector in natural infections from gametocytes contained in the blood of asymptomatic volunteers until sporozoites subsequently developed in the mosquito salivary glands. We did not find any selection of the mutant or wild-type pfcrt 76 allele during development in the Anopheles mosquito vector. However, microsatellite genotyping indicated that minority genotypes were favored during transmission through the mosquito. The analysis of changes in the proportions of mutant and wild-type pfcrt 76 alleles showed that, regardless of the genotype, the less-represented allele in the gametocyte population was more abundant in mosquito salivary glands, indicating a selective advantage of the minority allele in the vector. Selection of minority genotypes in the vector would explain the persistence of drug-resistant alleles in the absence of drug pressure in areas with high malaria endemicity and high genetic diversity. Our results may have important epidemiological implications, as they predict the rapid re-emergence and spread of resistant genotypes if antimalarials that had previously selected resistant parasites are reintroduced for malaria prevention or treatment.

IMPORTANCE Drug selection pressure in malaria patients is the cause of the emergence of resistant parasites. Resistance imposes a fitness cost for parasites in untreated infections, so withdrawal of the drug leads to the return of susceptible parasites. Little is known about the role of the malaria vector in this phenomenon. In an experimental study conducted in Cameroon, an area of high malaria transmission, we showed that the vector did not favor the parasites based on sensitivity or resistance criteria, but it did favor the selection of minority clones. This finding shows that the vector increases the diversity of plasmodial populations and could play an important role in falciparum malaria epidemiology by maintaining resistant clones despite the absence of therapeutic pressure.

Antimalarial drug resistance in the Central and Adamawa regions of Cameroon: Prevalence of mutations in P. falciparum crt, Pfmdr1, Pfdhfr and Pfdhps genes

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.