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BACKGROUND: Cholera outbreaks in western Democratic Republic of the Congo (DRC) are thought to be primarily the result of westward spread of cases from the Great Lakes Region. However, other patterns of spatial spread in this part of the country should not be excluded. The aim of this study was to explore alternative routes of spatial spread in western DRC. METHODS: A literature review was conducted to reconstruct major outbreak expansions of cholera in western DRC since its introduction in 1973. We also collected data on cholera cases reported at the health zone (HZ) scale by the national surveillance system during 2000–2018. Based on data from routine disease surveillance, we identified two subperiods (week 45, 2012–week 42, 2013 and week 40, 2017–week 52, 2018) for which the retrospective space–time permutation scan statistic was implemented to detect spatiotemporal clusters of cholera cases and then to infer the spread patterns in western DRC other than that described in the literature. RESULTS: Beyond westward and cross-border spread in the West Congo Basin from the Great Lakes Region, other dynamics of cholera epidemic propagation were observed from neighboring countries, such as Angola, to non-endemic provinces of southwestern DRC. Space–time clustering analyses sequentially detected clusters of cholera cases from southwestern DRC to the northern provinces, demonstrating a downstream-to-upstream spread along the Congo River. CONCLUSIONS: The spread of cholera in western DRC is not one-sided. There are other patterns of spatial spread, including a propagation from downstream to upstream areas along the Congo River, to be considered as preferential trajectories of cholera in western DRC. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-021-06986-9.

Background: Malaria cases were estimated to 207 million in 2013. One of the problems of malaria control is the emergence and spread of Plasmodium falciparum strains that become resistant to almost all drugs available. Monitoring drug resistance is essential for early detection and subsequent prevention of the spread of drug resistance by timely changes of treatment policy. This review was performed to gather all data available on P. falciparum molecular resistance in DR Congo, as baseline for future assessments. Methods: The search for this review was undertaken using the electronic databases PubMed and Google Scholar using the terms "malaria", "Congo", "resistance", "molecular", "antimalarial", "efficacy". Articles were classified based on year of collecting, year of publication, sample size and characteristics, molecular markers analysed and polymorphisms detected. Results: Thirteen articles were included and five genes have been analysed in these studies: pfcrt, pfdhps, pfdhfr, pfmdr1 and K13-propeller. The majority of studies included were not representative of the whole country. Conclusion: This systematic review demonstrates the lack of molecular resistance studies in DRC. Only 13 studies were identified in almost 15 years. The MOH must implement a national surveillance system for monitoring malaria drug resistance and this surveillance should be conducted frequently and country-representative. ; Peer reviewed

Plasmodiums are protozoa that may infect various hosts. Only five species are now recognized as naturally parasitizing humans: Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale and Plasmodium knowlesi. This fifth species, P. knowlesi, previously identified as naturally parasitizing the monkey Macaca fascicularis, has been microscopically confused for a long time with P. malariae or P. falciparum and it was not possible to correctly differentiate them until the advent of molecular biology. To date, natural human infections with P. knowlesi only occur in Southeast Asia and a similar phenomenon of natural transmission of simian plasmodium to humans has not been reported elsewhere. This study was conducted to investigate a possible transmission of African small monkey's plasmodium to humans in populations living near the rainforest of the Democratic Republic of Congo (DRC) where several species of non-human primates are living. Two successive real-time PCRs were identified in the literature and used in combination for purpose. Only P. falciparum was found in this study. However, studies with larger samples and with more advanced techniques should be conducted. ; Peer reviewed

Malaria remains a major public health problem in the Democratic Republic of Congo (DRC) with 14 million cases reported by the WHOMalaria Report in 2014. Asymptomaticmalaria cases are known to be prevalent in endemic areas and are generally untreated,resulting in a significant source of gametocytes that may serve as reservoir of disease transmission. Considering that microscopycertainly underestimates the prevalence of Plasmodium infections within symptomatic carriers and that PCR assays are currentlyrecognized as the most sensitive methods for Plasmodium identification, this study was conducted to weigh the asymptomatic carriage in DRC by a molecular method. Six provinces were randomly selected for blood collection in which 80 to 100 individuals were included in the study. Five hundred and eighty blood sampleswere collected andmolecular diagnosiswas performed. Globally, almost half of the samples collected from asymptomatic individuals (280/580; 48.2%) had Plasmodium infections and the most species identified was P. falciparum alone in combination with P. malariae. The high prevalence reported here should interpellate the bodies involved in malaria control in DR Congo to take into account asymptomatic carriers in actions taken and consider asymptomatic malaria as a major hurdle for malaria elimination. ; Peer reviewed

BACKGROUND: In 2001, the World Health Organization (WHO) has recommended the use of artemisinin-based combination therapy (ACT) as the first-line treatment of uncomplicated malaria cases, as monotherapies had become ineffective in many parts of the world. As a result, the Democratic Republic of Congo (DRC) withdrew chloroquine (CQ) from its malaria treatment policy in 2002 and an artesunate (AS)-amodiaquine (AQ) combination became the ACT of choice in DRC in 2005. AQ-resistance (AQR) has been reported in several parts of the world and mutations in codons 72-76 of the Plasmodium falciparum chloroquine-resistance transporter (pfcrt) gene have been strongly correlated with resistance, especially mutations encoding the SVMNT haplotype. This haplotype was first identified in Southeast Asia and South America but was recently reported in two African countries neighbouring DRC. These facts raised two questions: the first about the evolution of CQ resistance (CQR) in DRC and the second about the presence of the SVMNT haplotype, which would compromise the use of AQ as a partner drug for ACT. METHODS: A total of 213 thick blood films were randomly collected in 2010 from a paediatric clinic in Kinshasa, DRC. Microscopy controls and real-time polymerase chain reaction (RT-PCR) were performed for Plasmodium species identification. Haplotypes of the pfcrt gene were determined by sequencing. RESULTS: The K76T mutation was detected in 145 out of 198 P. falciparum-positive samples (73.2%).In these 145 resistant strains, only the CVIET haplotype was detected. CONCLUSIONS: This study is the first to assess the molecular markers of resistance to CQ and AQ after the introduction of ACT in DRC. The results suggest first that CQR is decreasing, as wild-type pfcrt haplotypes were found in only 26.8% of the samples and secondly that the SVMNT haplotype is not yet present in Kinshasa, suggesting that AQ remains valid as a partner drug for ACT in this region. ; Peer reviewed

Background: The loss of chloroquine (CQ) efectiveness has led to its withdrawal from national policies as a frst-line treatment for uncomplicated malaria in several endemic countries, such as the Democratic Republic of Congo (DRC). The K76T mutation on the pfcrt gene has been identifed as a marker of CQ resistance and the SVMNT haplotype in codons 72–76 on the same gene has been associated with resistance to amodiaquine (AQ). In the DRC, the prevalence of K76T has decreased from 100% in 2000 to 63.9% in 2014. The purpose of this study was to determine the prevalence of K76T mutations in circulating strains of Plasmodium falciparum, 16 years after CQ withdrawal in the DRC and to investigate the presence of the SVMNT haplotype. Methods: In 2017, ten geographical sites across the DRC were selected. Dried blood samples were collected from patients attending health centres. Malaria was frst detected by a rapid diagnostic test (RDT) available on site (SD Bioline Malaria Ag Pf or CareStart Malaria Pf) or thick blood smear and then confrmed by a P. falciparum species-specifc real-time PCR assay. A pfcrt gene segment containing a fragment that encodes amino acids at positions 72–76 was amplifed by conventional PCR before sequencing. Results: A total of 1070 patients were enrolled. Of the 806 PCR-confrmed P. falciparum positive samples, 764 were successfully sequenced. The K76T mutation was detected in 218 samples (28.5%; 95% CI 25.4%–31.9%), mainly (96%) with the CVIET haplotype. Prevalence of CQ resistance marker was unequally distributed across the country, ranging from 1.5% in Fungurume to 89.5% in Katana. The SVMNT haplotype, related to AQ resistance, was not detected. Conclusion: Overall, the frequency of the P. falciparum CQ resistance marker has decreased signifcantly and no resistance marker to AQ was detected in the DRC in 2017. However, the between regions variability of CQ resistance remains high in the country. Further studies are needed for continuous monitoring of the CQ resistance level for its prospective re-use in malaria management. The absence of the AQ resistance marker is in line with the use of this drug in the current DRC malaria treatment policy. ; Peer reviewed

Objectives: In the Democratic Republic of Congo (DRC), the neuromeningeal cryptococcosis (NMC) hospital prevalence varies between 8.8 and 11% with a death rate of about 50%. However, the Cryptococcus isolates circulating are poorly and formerly described. We describe the molecular characterization of Cryptococcus spp. isolated from people living with HIV (PLWHIV), and the association between NMC severity factors and the Cryptococcus multilocus sequence typing (MLST) profiles. Materials & Methods: Cerebral spinal fluid (CSF) was collected from PLWHIV with neuromeningeal syndrome hospitalized in three Kinshasa public hospitals from 1 February 2019 to 29 February 2020, and cultured on Sabouraud dextrose agar + chloramphenicol medium afterwards. Serotyping PCR, internal transcribed spacer (ITS) sequencing, and MLST from next-generation sequencing (NGS) data were performed to genotype the Cryptococcus isolates. Raw NGS data were processed and the loci alleles were manually extracted using Geneious software. NMC severity factors such as hypoglycorrhachia (30 cm water), and the patient pejorative outcome were compared to the Cryptococcus sequence type (ST)-MLST profile which was identified, using Pearson chi-square test or Fisher exact test. Results: Out of 29 isolates included in the present study, 23 (79.3%; 95% IC: 65.5–93.1) have been identified as serotype A using serotyping PCR, while 6 (20.7%; 95% IC: 6.9–34.5) had unidentifiable profile. Moreover, all the 29 isolates have been characterized by ITS sequencing as follow: Cryptococcus neoformans var. grubii (23 of 29 isolates, 79.3%), Cryptococcus curvatus (5 of 29, 17.2%), and Cryptococcus laurentii (1 of 29, 3.5%). Apart from this highlighted species diversity, C. neoformans var. grubii isolates were all identified as molecular type VNI using the MLST ISHAM scheme, with seven different STs including ST93 (14 out of 23, 60.9%), ST53 (1 out of 23, 4.3%), ST31 (1 out of 23, 4.3%), ST5 (1 out of 23, 4.3%), ST4 (1 out of 23, 4.3%), ST69 (1 out 23, 4.3%), and one novel ST not yet reported worldwide (2 out of 23, 8.6%). Furthermore, two isolates (8.6%) showed a mixed molecular profile (under investigation). Phylogenetic analysis carried out by the unweighted pair group method with arithmetic mean algorithm (UPGMA) of concatenated gene sequences from the seven MLST loci indicated that the main ST isolated in this study is very close to the only isolate previously reported from the DRC. The others are distant from it, even more so for ST69. All the STs identified in the present study have been isolated in the neighbouring countries of the DRC except for ST53, which has only been reported in Southeast Asia. Among NMC severity factors, only the patient pejorative outcome was associated with the minority STs infections (87.5%, p = 0.02) (ST53, ST31, ST5, ST4, STA, ST69). Conclusions: Molecular analysis of Cryptococcus spp. isolates showed wide species diversity, and ST-MLST heterogenicity within the only one molecular type identified. The existence of the STs isolated in this study in the DRC neighbouring countries suggests probable close-to-home spread. Furthermore, infections due to minority STs were associated with a pejorative outcome than those due to ST93. ; Peer reviewed

BACKGROUND: Because of the loss of chloroquine (CQ) effectiveness, the Democratic Republic of Congo (DRC)'s malaria treatment policy replaced CQ by sulfadoxine–pyrimethamine (SP) as first-line treatment of uncomplicated malaria in 2003, which in turn was replaced by artemisinin-based combination therapies (ACT) in 2005. The World Health Organization (WHO) recommends monitoring of anti-malarial drug resistance every 2 years. The study aimed to provide baseline data for biennial molecular surveillance of anti-malarial drug resistance by comparing data from a study conducted in 2019 to previously published data from a similar study conducted in 2017 in the DRC. METHODS: From July to November 2019, a cross-sectional study was conducted in ten sites which were previously selected for a similar study conducted in 2017 across the DRC. P. falciparum malaria was diagnosed by a rapid diagnostic test (RDT) or by microscopy and dried blood samples (DBS) were taken from patients who had a positive test. Segments of interest in pfcrt and pfk13 genes were amplified by conventional PCR before sequencing. RESULTS: Out of 1087 enrolled patients, 906 (83.3%) were PCR-confirmed for P. falciparum. Like in the 2017-study, none of the mutations known to be associated with Artemisinine (ART) resistance in Southeast Asia was detected. However, non-synonymous (NS) mutations with unknown functions were observed among which, A578S was detected in both 2017 and 2019-studies. The overall prevalence of pfcrt-K76T mutation that confers CQ-resistance was 22.7% in 2019-study compared to 28.5% in 2017-study (p-value = 0.069), but there was high variability between sites in the two studies. Like in 2017-study, the pfcrt 72–76 SVMNT haplotype associated with resistance to amodiaquine was not detected. CONCLUSION: The study reported, within 2 years, the non-presence of molecular markers currently known to be associated with resistance to ART and to AQ in P. falciparum isolated in the DRC. However, the presence of polymorphisms with as-yet unknown ...

Background: Because of the loss of chloroquine (CQ) effectiveness, the Democratic Republic of Congo (DRC)'s malaria treatment policy replaced CQ by sulfadoxine–pyrimethamine (SP) as first‑line treatment of uncomplicated malaria in 2003, which in turn was replaced by artemisinin‑based combination therapies (ACT) in 2005. The World Health Organization (WHO) recommends monitoring of anti‑malarial drug resistance every 2 years. The study aimed to provide baseline data for biennial molecular surveillance of anti‑malarial drug resistance by comparing data from a study conducted in 2019 to previously published data from a similar study conducted in 2017 in the DRC. Methods: From July to November 2019, a cross‑sectional study was conducted in ten sites which were previously selected for a similar study conducted in 2017 across the DRC. P. falciparum malaria was diagnosed by a rapid diagnostic test (RDT) or by microscopy and dried blood samples (DBS) were taken from patients who had a positive test. Segments of interest in pfcrt and pfk13 genes were amplified by conventional PCR before sequencing. Results: Out of 1087 enrolled patients, 906 (83.3%) were PCR‑confirmed for P. falciparum. Like in the 2017‑study, none of the mutations known to be associated with Artemisinine (ART) resistance in Southeast Asia was detected. How‑ ever, non‑synonymous (NS) mutations with unknown functions were observed among which, A578S was detected in both 2017 and 2019‑studies. The overall prevalence of pfcrt‑K76T mutation that confers CQ‑resistance was 22.7% in 2019‑study compared to 28.5% in 2017‑study (p‑value = 0.069), but there was high variability between sites in the two studies. Like in 2017‑study, the pfcrt 72–76 SVMNT haplotype associated with resistance to amodiaquine was not detected. Conclusion: The study reported, within 2 years, the non‑presence of molecular markers currently known to be associated with resistance to ART and to AQ in P. falciparum isolated in the DRC. However, the presence of polymorphisms with as‑yet unknown functions was observed, requiring further characterization. Moreover, an overall decrease in the prevalence of CQ‑resistance marker was observed in the DRC, but this prevalence remained highly variable from region to region

Background: Because of the loss of chloroquine (CQ) effectiveness, the Democratic Republic of Congo (DRC)'s malaria treatment policy replaced CQ by sulfadoxine–pyrimethamine (SP) as first‑line treatment of uncomplicated malaria in 2003, which in turn was replaced by artemisinin‑based combination therapies (ACT) in 2005. The World Health Organization (WHO) recommends monitoring of anti‑malarial drug resistance every 2 years. The study aimed to provide baseline data for biennial molecular surveillance of anti‑malarial drug resistance by comparing data from a study conducted in 2019 to previously published data from a similar study conducted in 2017 in the DRC. Methods: From July to November 2019, a cross‑sectional study was conducted in ten sites which were previously selected for a similar study conducted in 2017 across the DRC. P. falciparum malaria was diagnosed by a rapid diagnostic test (RDT) or by microscopy and dried blood samples (DBS) were taken from patients who had a positive test. Segments of interest in pfcrt and pfk13 genes were amplified by conventional PCR before sequencing. Results: Out of 1087 enrolled patients, 906 (83.3%) were PCR‑confirmed for P. falciparum. Like in the 2017‑study, none of the mutations known to be associated with Artemisinine (ART) resistance in Southeast Asia was detected. How‑ ever, non‑synonymous (NS) mutations with unknown functions were observed among which, A578S was detected in both 2017 and 2019‑studies. The overall prevalence of pfcrt‑K76T mutation that confers CQ‑resistance was 22.7% in 2019‑study compared to 28.5% in 2017‑study (p‑value = 0.069), but there was high variability between sites in the two studies. Like in 2017‑study, the pfcrt 72–76 SVMNT haplotype associated with resistance to amodiaquine was not detected. Conclusion: The study reported, within 2 years, the non‑presence of molecular markers currently known to be associated with resistance to ART and to AQ in P. falciparum isolated in the DRC. However, the presence of polymorphisms with as‑yet unknown functions was observed, requiring further characterization. Moreover, an overall decrease in the prevalence of CQ‑resistance marker was observed in the DRC, but this prevalence remained highly variable from region to region

Background: The national policy for malaria treatment of the Democratic Republic of Congo recommends two first-line artemisinin-based combinations for the treatment of uncomplicated malaria: artesunate-amodiaquine and artemether-lumefantrine. This study investigated the presence of markers associated with resistance to the current first-line artemisinin-based combination therapy (ACT) in isolates of Plasmodium falciparum from treatment failure patients in the Democratic Republic of Congo. Methods: From November 2018 to November 2019, dried blood spots were taken from patients returning to health centres for fever within 28 days after an initial malaria treatment in six sentinel sites of the National Malaria Control Programme across Democratic Republic of Congo. The new episode of malaria was first detected by a rapid diagnostic test and then confirmed by a real-time PCR assay to define treatment failure. Fragments of interest in pfk13 and pfcrt genes were amplified by conventional PCR before sequencing and the Pfmdr1 gene copy number was determined by a TaqMan real-time PCR assay. Results: Out of 474 enrolled patients, 364 (76.8%) were confirmed positive by PCR for a new episode of P. falciparum malaria, thus considered as treatment failure. Of the 325 P. falciparum isolates obtained from 364 P. falciparum-positive patients and successfully sequenced in the pfk13-propeller gene, 7 (2.2%) isolates carried non-synonymous mutations, among which 3 have been previously reported (N498I, N554K and A557S) and 4 had not yet been reported (F506L, E507V, D516E and G538S). Of the 335 isolates successfully sequenced in the pfcrt gene, 139 (41.5%) harboured the K76T mutation known to be associated with chloroquine resistance. The SVMNT haplotype associated with resistance to amodiaquine was not found. None of the isolates carried an increased copy number of the pfmdr1 gene among the 322 P. falciparum isolates successfully analysed.

BACKGROUND: The national policy for malaria treatment of the Democratic Republic of Congo recommends two first-line artemisinin-based combinations for the treatment of uncomplicated malaria: artesunate-amodiaquine and artemether-lumefantrine. This study investigated the presence of markers associated with resistance to the current first-line artemisinin-based combination therapy (ACT) in isolates of Plasmodium falciparum from treatment failure patients in the Democratic Republic of Congo. METHODS: From November 2018 to November 2019, dried blood spots were taken from patients returning to health centres for fever within 28 days after an initial malaria treatment in six sentinel sites of the National Malaria Control Programme across Democratic Republic of Congo. The new episode of malaria was first detected by a rapid diagnostic test and then confirmed by a real-time PCR assay to define treatment failure. Fragments of interest in pfk13 and pfcrt genes were amplified by conventional PCR before sequencing and the Pfmdr1 gene copy number was determined by a TaqMan real-time PCR assay. RESULTS: Out of 474 enrolled patients, 364 (76.8%) were confirmed positive by PCR for a new episode of P. falciparum malaria, thus considered as treatment failure. Of the 325 P. falciparum isolates obtained from 364 P. falciparum-positive patients and successfully sequenced in the pfk13-propeller gene, 7 (2.2%) isolates carried non-synonymous mutations, among which 3 have been previously reported (N498I, N554K and A557S) and 4 had not yet been reported (F506L, E507V, D516E and G538S). Of the 335 isolates successfully sequenced in the pfcrt gene, 139 (41.5%) harboured the K76T mutation known to be associated with chloroquine resistance. The SVMNT haplotype associated with resistance to amodiaquine was not found. None of the isolates carried an increased copy number of the pfmdr1 gene among the 322 P. falciparum isolates successfully analysed. CONCLUSION: No molecular markers currently known to be associated with resistance to the first-line ACT in use were detected in isolates of P. falciparum from treatment failure patients. Regular monitoring through in vivo drug efficacy and molecular studies must continue to ensure the effectiveness of malaria treatment in Democratic Republic of Congo. ; Peer reviewed

Background: The national policy for malaria treatment of the Democratic Republic of Congo recommends two first-line artemisinin-based combinations for the treatment of uncomplicated malaria: artesunate-amodiaquine and artemether-lumefantrine. This study investigated the presence of markers associated with resistance to the current first-line artemisinin-based combination therapy (ACT) in isolates of Plasmodium falciparum from treatment failure patients in the Democratic Republic of Congo. Methods: From November 2018 to November 2019, dried blood spots were taken from patients returning to health centres for fever within 28 days after an initial malaria treatment in six sentinel sites of the National Malaria Control Programme across Democratic Republic of Congo. The new episode of malaria was first detected by a rapid diagnostic test and then confirmed by a real-time PCR assay to define treatment failure. Fragments of interest in pfk13 and pfcrt genes were amplified by conventional PCR before sequencing and the Pfmdr1 gene copy number was determined by a TaqMan real-time PCR assay. Results: Out of 474 enrolled patients, 364 (76.8%) were confirmed positive by PCR for a new episode of P. falciparum malaria, thus considered as treatment failure. Of the 325 P. falciparum isolates obtained from 364 P. falciparum-positive patients and successfully sequenced in the pfk13-propeller gene, 7 (2.2%) isolates carried non-synonymous mutations, among which 3 have been previously reported (N498I, N554K and A557S) and 4 had not yet been reported (F506L, E507V, D516E and G538S). Of the 335 isolates successfully sequenced in the pfcrt gene, 139 (41.5%) harboured the K76T mutation known to be associated with chloroquine resistance. The SVMNT haplotype associated with resistance to amodiaquine was not found. None of the isolates carried an increased copy number of the pfmdr1 gene among the 322 P. falciparum isolates successfully analysed.

Background:The loss of chloroquine (CQ) effectiveness has led to its withdrawal from national policies as a first‑line treatment for uncomplicated malaria in several endemic countries, such as the Democratic Republic of Congo (DRC). The K76T mutation on the pfcrt gene has been identified as a marker of CQ resistance and the SVMNT haplotype in codons 72–76 on the same gene has been associated with resistance to amodiaquine (AQ). In the DRC, the preva‑lence of K76T has decreased from 100% in 2000 to 63.9% in 2014. The purpose of this study was to determine the prevalence of K76T mutations in circulating strains of Plasmodiumfalciparum, 16 years after CQ withdrawal in the DRC and to investigate the presence of the SVMNT haplotype.Methods:In 2017, ten geographical sites across the DRC were selected. Dried blood samples were collected from patients attending health centres. Malaria was first detected by a rapid diagnostic test (RDT ) available on site (SD Bio‑line Malaria Ag Pf or CareStart Malaria Pf) or thick blood smear and then confirmed by a P.falciparum species‑specific real‑time PCR assay. A pfcrt gene segment containing a fragment that encodes amino acids at positions 72–76 was amplified by conventional PCR before sequencing.Results:A total of 1070 patients were enrolled. Of the 806 PCR‑confirmed P.falciparum positive samples, 764 were successfully sequenced. The K76T mutation was detected in 218 samples (28.5%; 95% CI 25.4%–31.9%), mainly (96%) with the CVIET haplotype. Prevalence of CQ resistance marker was unequally distributed across the country, ranging from 1.5% in Fungurume to 89.5% in Katana. The SVMNT haplotype, related to AQ resistance, was not detected.Conclusion:Overall, the frequency of the P.falciparum CQ resistance marker has decreased significantly and no resistance marker to AQ was detected in the DRC in 2017. However, the between regions variability of CQ resistance remains high in the country. Further studies are needed for continuous monitoring of the CQ resistance level for its prospective re‑use in malaria management. The absence of the AQ resistance marker is in line with the use of this drug in the current DRC malaria treatment policy.

BACKGROUND: The loss of chloroquine (CQ) effectiveness has led to its withdrawal from national policies as a first-line treatment for uncomplicated malaria in several endemic countries, such as the Democratic Republic of Congo (DRC). The K76T mutation on the pfcrt gene has been identified as a marker of CQ resistance and the SVMNT haplotype in codons 72–76 on the same gene has been associated with resistance to amodiaquine (AQ). In the DRC, the prevalence of K76T has decreased from 100% in 2000 to 63.9% in 2014. The purpose of this study was to determine the prevalence of K76T mutations in circulating strains of Plasmodium falciparum, 16 years after CQ withdrawal in the DRC and to investigate the presence of the SVMNT haplotype. METHODS: In 2017, ten geographical sites across the DRC were selected. Dried blood samples were collected from patients attending health centres. Malaria was first detected by a rapid diagnostic test (RDT) available on site (SD Bioline Malaria Ag Pf or CareStart Malaria Pf) or thick blood smear and then confirmed by a P. falciparum species-specific real-time PCR assay. A pfcrt gene segment containing a fragment that encodes amino acids at positions 72–76 was amplified by conventional PCR before sequencing. RESULTS: A total of 1070 patients were enrolled. Of the 806 PCR-confirmed P. falciparum positive samples, 764 were successfully sequenced. The K76T mutation was detected in 218 samples (28.5%; 95% CI 25.4%–31.9%), mainly (96%) with the CVIET haplotype. Prevalence of CQ resistance marker was unequally distributed across the country, ranging from 1.5% in Fungurume to 89.5% in Katana. The SVMNT haplotype, related to AQ resistance, was not detected. CONCLUSION: Overall, the frequency of the P. falciparum CQ resistance marker has decreased significantly and no resistance marker to AQ was detected in the DRC in 2017. However, the between regions variability of CQ resistance remains high in the country. Further studies are needed for continuous monitoring of the CQ resistance level for its ...