Dataset Information

Markers of sulfadoxine-pyrimethamine resistance in Eastern Democratic Republic of Congo; implications for malaria chemoprevention.

ABSTRACT:

Background

Sulfadoxine-pyrimethamine (SP) is a cornerstone of malaria chemoprophylaxis and is considered for programmes in the Democratic Republic of Congo (DRC). However, SP efficacy is threatened by drug resistance, that is conferred by mutations in the dhfr and dhps genes. The World Health Organization has specified that intermittent preventive treatment for infants (IPTi) with SP should be implemented only if the prevalence of the dhps K540E mutation is under 50%. There are limited current data on the prevalence of resistance-conferring mutations available from Eastern DRC. The current study aimed to address this knowledge gap.

Methods

Dried blood-spot samples were collected from clinically suspected malaria patients [outpatient department (OPD)] and pregnant women attending antenatal care (ANC) in four sites in North and South Kivu, DRC. Quantitative PCR (qPCR) was performed on samples from individuals with positive and with negative rapid diagnostic test (RDT) results. Dhps K450E and A581G and dhfr I164L were assessed by nested PCR followed by allele-specific primer extension and detection by multiplex bead-based assays.

Results

Across populations, Plasmodium falciparum parasite prevalence was 47.9% (1160/2421) by RDT and 71.7 (1763/2421) by qPCR. Median parasite density measured by qPCR in RDT-negative qPCR-positive samples was very low with a median of 2.3 parasites/µL (IQR 0.5-25.2). Resistance genotyping was successfully performed in RDT-positive samples and RDT-negative/qPCR-positive samples with success rates of 86.2% (937/1086) and 55.5% (361/651), respectively. The presence of dhps K540E was high across sites (50.3-87.9%), with strong evidence for differences between sites (p?ConclusionsThe prevalence of the SP resistance marker dhps K540E exceeds 50% in all four study sites in North and South Kivu, DRC. K540E mutations regularly co-occurred with mutations in dhps A581G but not with the dhfr I164L mutation. The current results do not support implementation of IPTi with SP in the study area.

SUBMITTER: van Lenthe M

PROVIDER: S-EPMC6921399 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

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Publications

Markers of sulfadoxine-pyrimethamine resistance in Eastern Democratic Republic of Congo; implications for malaria chemoprevention.

van Lenthe Marit M van der Meulen Renske R Lassovski Maryvonne M Ouabo Adelaide A Bakula Edwige E Badio Colette C Cibenda Deogratias D Okell Lucy L Piriou Erwan E Grignard Lynn L Lanke Kjerstin K Rao Bhargavi B Bousema Teun T Roper Cally C

Malaria journal 20191218 1

<h4>Background</h4>Sulfadoxine-pyrimethamine (SP) is a cornerstone of malaria chemoprophylaxis and is considered for programmes in the Democratic Republic of Congo (DRC). However, SP efficacy is threatened by drug resistance, that is conferred by mutations in the dhfr and dhps genes. The World Health Organization has specified that intermittent preventive treatment for infants (IPTi) with SP should be implemented only if the prevalence of the dhps K540E mutation is under 50%. There are limited c ...[more]

PMID: 31852480

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Project description:BACKGROUND:Point mutations in Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes which confer resistance to sulfadoxine-pyrimethamine (SP) occur at increasing rates. The present study aimed to identify Pfdhfr and Pfdhps mutations in P. falciparum isolates recovered from women who received two doses of SP during pregnancy in Bandundu, the Democratic Republic of Congo (DRC). METHODS:A total of 48 women with confirmed P. falciparum infection were enrolled in the study. Finger-prick blood samples that were collected on filter paper at the time of delivery were used for DNA isolation. Pfdhfr and Pfdhps genes were amplified by a nested PCR protocol. DNA sequencing was performed on both strands, and the point mutations were analysed. RESULTS:All of the 48 (100.0%) P. falciparum isolates carried at least one polymorphism in both genes. The wild-type haplotypes of Pfdhfr (CNCSI [C50, N51, C59, S108, I164]) and Pfdhps (SAKAA [S436, A437, K540, A581, A613]) were not observed in the study. In Pfdhfr, N51I (85.4%), C59R (60.4%), and S108N (100.0%) polymorphisms were detected. Triple mutation (CIRNI) (mutant amino acids are underlined) was the most prevalent (47.9%) Pfdhfr haplotype. In the study, all P. falciparum isolates (100.0%) harboured the A437G allele in Pfdhps gene. Also, K540E and A581G polymorphisms were observed in one (2.1%) isolate. Single mutant haplotype (SGKAA) was detected in 97.9% of the isolates. Mutant Pfdhfr and Pfdhps allele combinations revealed quintuple (CICNI-SGEGA; 2.1%), quadruple (CIRNI-SGKAA; 47.9%), triple (CICNI-SGKAA; 35.4%, CNRNI-SGKAA; 12.5%), and double (CNCNI-SGKAA; 2.1%) haplotypes. CONCLUSIONS:In the study, the rate of SGEGA haplotype was low (2.1%). Although K540E and A581G alleles are more common in Eastern Africa, a distinct lineage of SGEGA is also present in the DRC, which is located in Central Africa. This haplotype is associated with decreased efficacy of SP in pregnant women and infants, therefore, it should be carefully considered in the DRC and SP resistance should be routinely monitored.

Project description:BackgroundIn malaria endemic areas, schoolchildren usually have asymptomatic malaria infections and consequently remain untreated. Therefore, intermittent preventive treatment with sulfadoxine-pyrimethamine in schoolchildren would be a plausible strategy in malaria stable transmission areas to prevent anaemia and malnutrition. However, in contrast to infancy and pregnancy, antimalaria intermittent preventive treatment in children has been barely investigated. As the implementation of intermittent preventive treatment may be challenged by sulfadoxine-pyrimethamine resistance, sulfadoxine-pyrimethamine combined with piperaquine may be a better alternative than sulfadoxine-pyrimethamine monotherapy. A clinical trial is being conducted to assess the efficacy and safety of intermittent preventive treatments versus controls in Democratic Republic of Congo (DRCongo) schoolchildren and their impact on sulfadoxine-pyrimethamine resistance.Methods/designA phase IIIb, randomised, controlled trial will enroll asymptomatic schoolchildren. For interventions, sulfadoxine-pyrimethamine is compared to sulfadoxine-pyrimethamine plus piperaquine and to a control group. The two treatments are given four-monthly from baseline for a year as a single dose for sulfadoxine-pyrimethamine and two doses at 24-hour intervals for piperaquine. All participants receive praziquantel and albendazole as mass-treatment for helminthiasis at enrolment. The primary endpoint is haemoglobin concentration change at 12 months follow-up. Secondary endpoints are malaria parasite load and malaria prevalence, at baseline and at month 12. Malaria and helminthiasis incidence will be monitored throughout the study. Statistical analysis will use multilevel modelling due to repeated measurements and clustering effect of participants.DiscussionThe very few studies on intermittent preventive treatment in schoolchildren in malaria stable transmission areas have contradictory results. This randomised controlled trial is unique in comparing efficacy and safety of a prophylactic combination therapy to monotherapy or a control group after 12 months follow-up. Resistance markers for sulfadoxine-pyrimethamine (including break through parasitaemias) will also be recorded. Its uniqueness lies also in the fact that we use piperaquine, a long acting antimalarial, in combination with sulfadoxine-pyrimethamine. Artemisinin derivatives have been excluded as it is part of the treatment policies in virtually all malaria endemic countries. Our findings may, therefore, contribute to the public health of youngsters who fail to thrive and grow due to multiple morbidities.Trial registrationNCT01722539; PACTR201211000449323.

Project description:BackgroundTrials evaluating antimalarials for intermittent preventive treatment in pregnancy (IPTp) have shown that dihydroartemisinin-piperaquine (DP) is a more efficacious antimalarial than sulfadoxine-pyrimethamine (SP); however, SP is associated with higher birthweight, suggesting that SP demonstrates "nonmalarial" effects. Chemoprevention of nonmalarial febrile illnesses (NMFIs) was explored as a possible mechanism.MethodsIn this secondary analysis, we leveraged data from 654 pregnant Ugandan women without HIV infection who participated in a randomized controlled trial comparing monthly IPTp-SP with IPTp-DP. Women were enrolled between 12 and 20 gestational weeks and followed through delivery. NMFIs were measured by active and passive surveillance and defined by the absence of malaria parasitemia. We quantified associations among IPTp regimens, incident NMFIs, antibiotic prescriptions, and birthweight.ResultsMean "birthweight for gestational age" Z scores were 0.189 points (95% CI, .045-.333) higher in women randomized to IPTp-SP vs IPTp-DP. Women randomized to IPTp-SP had fewer incident NMFIs (incidence rate ratio, 0.74; 95% CI, .58-.95), mainly respiratory NMFIs (incidence rate ratio, 0.69; 95% CI, .48-1.00), vs IPTp-DP. Counterintuitively, respiratory NMFI incidence was positively correlated with birthweight in multigravidae. In total 75% of respiratory NMFIs were treated with antibiotics. Although overall antibiotic prescriptions were similar between arms, for each antibiotic prescribed, "birthweight for gestational age" Z scores increased by 0.038 points (95% CI, .001-.074).ConclusionsMonthly IPTp-SP was associated with reduced respiratory NMFI incidence, revealing a potential nonmalarial mechanism of SP and supporting current World Health Organization recommendations for IPTp-SP, even in areas with high-grade SP resistance. While maternal respiratory NMFIs are known risk factors of lower birthweight, most women in our study were presumptively treated with antibiotics, masking the potential benefit of SP on birthweight mediated through preventing respiratory NMFIs.

Dataset Information

Markers of sulfadoxine-pyrimethamine resistance in Eastern Democratic Republic of Congo; implications for malaria chemoprevention.

Background

Methods

Results

Publications

Markers of sulfadoxine-pyrimethamine resistance in Eastern Democratic Republic of Congo; implications for malaria chemoprevention.

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