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The Cochrane Database of Systematic... Feb 2015Mosquitoes become infected with Plasmodium when they ingest gametocyte-stage parasites from an infected person's blood. Plasmodium falciparum gametocytes are sensitive... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Mosquitoes become infected with Plasmodium when they ingest gametocyte-stage parasites from an infected person's blood. Plasmodium falciparum gametocytes are sensitive to 8-aminoquinolines (8AQ), and consequently these drugs could prevent parasite transmission from infected people to mosquitoes and reduce the incidence of malaria. However, when used in this way, these drugs will not directly benefit the individual.In 2010, the World Health Organization (WHO) recommended a single dose of primaquine (PQ) at 0.75 mg/kg alongside treatment for P. falciparum malaria to reduce transmission in areas approaching malaria elimination. In 2013, the WHO revised this to 0.25 mg/kg to reduce risk of harms in people with G6PD deficiency.
OBJECTIVES
To assess the effects of PQ (or an alternative 8AQ) given alongside treatment for P. falciparum malaria on malaria transmission and on the occurrence of adverse events.
SEARCH METHODS
We searched the following databases up to 5 January 2015: the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library (Issue 1, 2015); MEDLINE (1966 to 5 January 2015); EMBASE (1980 to 5 January 2015); LILACS (1982 to 5 January 2015); metaRegister of Controlled Trials (mRCT); and the WHO trials search portal using 'malaria*', 'falciparum', 'primaquine', 8-aminoquinoline and eight individual 8AQ drug names as search terms. In addition, we searched conference proceedings and reference lists of included studies, and contacted researchers and organizations.
SELECTION CRITERIA
Randomized controlled trials (RCTs) or quasi-RCTs in children or adults, comparing PQ (or alternative 8AQ) as a single dose or short course alongside treatment for P. falciparum malaria, with the same malaria treatment given without PQ/8AQ.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened all abstracts, applied inclusion criteria and extracted data. We sought evidence of an impact on transmission (community incidence), infectiousness (mosquitoes infected from humans) and potential infectiousness (gametocyte measures). We calculated the area under the curve (AUC) for gametocyte density over time for comparisons for which data were available. We sought data on haematological and other adverse effects, asexual parasite clearance time and recrudescence. We stratified the analysis by artemisinin and non-artemisinin treatments; and by PQ dose (low < 0.4 mg/kg; medium ≥ 0.4 to < 0.6 mg/kg; high ≥ 0.6 mg/kg). We used the GRADE approach to assess evidence quality.
MAIN RESULTS
We included 17 RCTs and one quasi-RCT. Eight trials tested for G6PD status: six then excluded participants with G6PD deficiency, one included only those with G6PD deficiency, and one included all irrespective of status. The remaining 10 trials either did not report on whether they tested (eight trials), or reported that they did not test (two trials).Nine trials included study arms with artemisinin-based treatments and eleven included study arms with non-artemisinin-based treatments.Only one trial evaluated PQ given as a single dose of less than 0.4 mg/kg. PQ with artemisinin-based treatments: No trials evaluated effects on malaria transmission directly (incidence, prevalence or entomological inoculation rate) and none evaluated infectiousness to mosquitoes. For potential infectiousness, the proportion of people with detectable gametocytaemia on day eight was reduced by around two-thirds with the high dose PQ category (RR 0.29, 95% confidence interval (CI) 0.22 to 0.37; seven trials, 1380 participants, high quality evidence) and the medium dose PQ category (RR 0.30, 95% CI 0.16 to 0.56; one trial, 219 participants, moderate quality evidence). For the low dose category, the effect size was smaller and the 95% CIs include the possibility of no effect (dose: 0.1 mg/kg: RR 0.67, 95% CI 0.44 to 1.02; one trial, 223 participants, low quality evidence). Reductions in log(10)AUC estimates for gametocytaemia on days 1 to 43 with medium and high doses ranged from 24.3% to 87.5%. For haemolysis, one trial reported percent change in mean haemoglobin against baseline and did not detect a difference between the two arms (very low quality evidence). PQ with non-artemisinin treatments: No trials assessed effects on malaria transmission directly. Two small trials from the same laboratory in China evaluated infectiousness to mosquitoes, and reported that infectivity was eliminated on day 8 in 15/15 patients receiving high dose PQ compared to 1/15 in the control group (low quality evidence). For potential infectiousness, the proportion of people with detectable gametocytaemia on day 8 was reduced by three-fifths with high dose PQ category (RR 0.39, 95% CI 0.25 to 0.62; four trials, 186 participants, high quality evidence), and by around two-fifths with medium dose category (RR 0.60, 95% CI 0.49 to 0.75; one trial, 216 participants, high quality evidence), with no trial in the low dose PQ category reporting this outcome. Reduction in log(10)AUC for gametocytaemia days 1 to 43 were 24.3% and 27.1% for two arms in one trial giving medium dose PQ. No trials systematically sought evidence of haemolysis.Two trials evaluated the 8AQ bulaquine, and suggest the effects may be greater than PQ, but the small number of participants (N = 112) preclude a definite conclusion.
AUTHORS' CONCLUSIONS
In individual patients, PQ added to malaria treatments reduces gametocyte prevalence, but this is based on trials using doses of more than 0.4 mg/kg. Whether this translates into preventing people transmitting malaria to mosquitoes has rarely been tested in controlled trials, but there appeared to be a strong reduction in infectiousness in the two small studies that evaluated this. No included trials evaluated whether this policy has an impact on community malaria transmission.For the currently recommended low dose regimen, there is currently little direct evidence to be confident that the effect of reduction in gametocyte prevalence is preserved, or that it is safe in people with G6PD deficiency.
Topics: Antimalarials; Artemisinins; Artesunate; Chloroquine; Drug Combinations; Glucosephosphate Dehydrogenase Deficiency; Humans; Malaria, Falciparum; Mefloquine; Plasmodium falciparum; Primaquine; Pyrimethamine; Quinine; Randomized Controlled Trials as Topic; Sulfadoxine
PubMed: 25693791
DOI: 10.1002/14651858.CD008152.pub4 -
Malaria Journal Aug 2017Seasonal malaria chemoprevention (SMC) is a new strategy recommended by WHO in areas of highly seasonal transmission in March 2012. Although randomized controlled trials...
BACKGROUND
Seasonal malaria chemoprevention (SMC) is a new strategy recommended by WHO in areas of highly seasonal transmission in March 2012. Although randomized controlled trials (RCTs) have shown SMC to be highly effective, evidence and experience from routine implementation of SMC are limited.
METHODS
A non-randomized pragmatic trial with pre-post design was used, with one intervention district (Kita), where four rounds of SMC with sulfadoxine + amodiaquine (SP + AQ) took place in August-November 2014, and one comparison district (Bafoulabe). The primary aims were to evaluate SMC coverage and reductions in prevalence of malaria and anaemia when SMC is delivered through routine programmes using existing community health workers. Children aged 3-59 months from 15 selected localities per district, sampled with probability proportional to size, were surveyed and blood samples collected for malaria blood smears, haemoglobin (Hb) measurement, and molecular markers of drug resistance in two cross-sectional surveys, one before SMC (July 2014) and one after SMC (December 2014). Difference-in-differences regression models were used to assess and compare changes in malaria and anaemia in the intervention and comparison districts. Adherence and tolerability of SMC were assessed by cross-sectional surveys 4-7 days after each SMC round. Coverage of SMC was assessed in the post-SMC survey.
RESULTS
During round 1, 84% of targeted children received at least the first SMC dose, but coverage declined to 67% by round 4. Across the four treatment rounds, 54% of children received four complete SMC courses. Prevalence of parasitaemia was similar in intervention and comparison districts prior to SMC (23.4 vs 29.5%, p = 0.34) as was the prevalence of malaria illness (2.4 vs 1.9%, p = 0.75). After SMC, parasitaemia prevalence fell to 18% in the intervention district and increased to 46% in the comparison district [difference-in-differences (DD) OR = 0.35; 95% CI 0.20-0.60]. Prevalence of malaria illness fell to a greater degree in the intervention district versus the comparison district (DD OR = 0.20; 95% CI 0.04-0.94) and the same for moderate anaemia (Hb < 8 g/dL) (DD OR = 0.26, 95% CI 0.11-0.65). The frequency of the quintuple mutation (dhfr N51I, C59R and S108N + dhps A437G and K540E) remained low (5%) before and after intervention in both districts.
CONCLUSIONS
Routine implementation of SMC in Mali substantially reduced malaria and anaemia, with reductions of similar magnitude to those seen in previous RCTs. Improving coverage could further strengthen SMC impact. Trial registration clinical trial registration number NCT02894294.
Topics: Amodiaquine; Anemia; Antimalarials; Chemoprevention; Child; Child, Preschool; Cross-Sectional Studies; Drug Combinations; Female; Humans; Infant; Malaria; Male; Mali; Prevalence; Seasons; Sulfadoxine
PubMed: 28797263
DOI: 10.1186/s12936-017-1974-x -
Emerging Infectious Diseases May 2020Haiti is striving for zero local malaria transmission by the year 2025. Chloroquine remains the first-line treatment, and sulfadoxine/pyrimethamine (SP) has been used...
Haiti is striving for zero local malaria transmission by the year 2025. Chloroquine remains the first-line treatment, and sulfadoxine/pyrimethamine (SP) has been used for mass drug-administration pilot programs. In March 2016, nationwide molecular surveillance was initiated to assess molecular resistance signatures for chloroquine and SP. For 778 samples collected through December 2017, we used Sanger sequencing to investigate putative resistance markers to chloroquine (Pfcrt codons 72, 74, 75, and 76), sulfadoxine (Pfdhps codons 436, 437, 540, 581, 613), and pyrimethamine (Pfdhfr codons 50, 51, 59, 108, 164). No parasites harbored Pfcrt point mutations. Prevalence of the Pfdhfr S108N single mutation was 47%, and we found the triple mutant Pfdhfr haplotype (108N, 51I, and 59R) in a single isolate. We observed no Pfdhps variants except in 1 isolate (A437G mutation). These data confirm the lack of highly resistant chloroquine and SP alleles in Haiti and support the continued use of chloroquine and SP.
Topics: Alleles; Antimalarials; Chloroquine; Drug Resistance; Haiti; Humans; Malaria, Falciparum; Mutation; Plasmodium falciparum; Pyrimethamine; Sulfadoxine
PubMed: 32310062
DOI: 10.3201/eid2605.190556 -
Acta Tropica Dec 2023The 2022 malaria WHO reported around 4000 P. knowlesi infections in the South-East Asia region. In the same period, 72 positive cases were reported by the Department of...
BACKGROUND
The 2022 malaria WHO reported around 4000 P. knowlesi infections in the South-East Asia region. In the same period, 72 positive cases were reported by the Department of Disease Control in Thailand, suggesting a persistent infection. Little is known about dihydrofolate reductase (pkdhfr) and dihydropteroate synthase (pkdhps), putative antimalarial resistance markers for P. knowlesi. The relevant amplification and sequencing protocol are presently unavailable. In this study, we developed a protocol for amplifying and evaluating pkdhps mutations. The haplotype pattern of pkdhfr-pkdhps in Thai isolates was analyzed, and the effects of these pkdhps mutations were predicted by using a computer program.
METHODS
Pkdhps were amplified and sequenced from 28 P. knowlesi samples collected in 2008 and 2020 from nine provinces across Thailand. Combining pkdhfr sequencing data from previous work with pkdhps data to analyze polymorphisms of pkdhfr and pkdhps haplotype. Protein modeling and molecular docking were constructed using two inhibitors, sulfadoxine and sulfamethoxazole, and further details were obtained through analyses of protein-ligand interactions by using the Genetic Optimisation for Ligand Docking program. A phylogenetic tree cluster analysis was reconstructed to compare the P. knowlesi Malaysia isolates.
RESULTS
Five nonsynonymous mutations in the pkdhps were detected outside the equivalence of the binding pocket sites to sulfadoxine and sulfamethoxazole, which are at N391S, E421G, I425R, A449S, and N517S. Based on the modeling and molecular docking analyses, the N391S and N517S mutations located close to the enzyme-binding pocket demonstrated a different docking score and protein-ligand interaction in loop 2 of the enzyme. These findings indicated that it was less likely to induce drug resistance. Of the four haplotypes of pkdhfr-pkdhps, the most common one is the R34L pkdhfr mutation and the pkdhps quadruple mutation (GRSS) at E421G, I425R, A449S, and N517S, which were observed in P. knowlesi in southern Thailand (53.57%). Based on the results of neighbor-joining analysis for pkdhfr and pkdhps, the samples isolated from eastern Thailand displayed a close relationship with Cambodia isolates, while southern Thailand isolates showed a long branch separated from the Malaysian isolates.
CONCLUSIONS
A new PCR protocol amplification and evaluation of dihydropteroate synthase mutations in Knowlesi (pkdhps) has been developed. The most prevalent pkdhfr-pkdhps haplotypes (53.57%) in southern Thailand are R34L pkdhfr mutation and pkdhps quadruple mutation. Further investigation requires additional phenotypic data from clinical isolates, transgenic lines expressing mutant alleles, or recombinant proteins.
Topics: Sulfadoxine; Pyrimethamine; Tetrahydrofolate Dehydrogenase; Dihydropteroate Synthase; Plasmodium knowlesi; Thailand; Molecular Docking Simulation; Ligands; Phylogeny; Antimalarials; Drug Resistance; Sulfamethoxazole; Plasmodium falciparum
PubMed: 37683820
DOI: 10.1016/j.actatropica.2023.107016 -
The Pediatric Infectious Disease Journal Mar 2017
Topics: Antimalarials; Drug Combinations; Drug Therapy, Combination; Humans; Pyrimethamine; Sulfadoxine; Toxoplasmosis, Congenital
PubMed: 28187118
DOI: 10.1097/INF.0000000000001435 -
Scientific Reports Oct 2021Previous studies have shown that P. falciparum parasites in South America have undergone population bottlenecks resulting in clonal lineages that are differentially...
Previous studies have shown that P. falciparum parasites in South America have undergone population bottlenecks resulting in clonal lineages that are differentially distributed and that have been responsible for several outbreaks different endemic regions. In this study, we explored the genomic profile of 18 P. falciparum samples collected in the Peruvian Amazon Basin (Loreto) and 6 from the Peruvian North Coast (Tumbes). Our results showed the presence of three subpopulations that matched previously typed lineages in Peru: Bv1 (n = 17), Clonet D (n = 4) and Acre-Loreto type (n = 3). Gene coverage analysis showed that none of the Bv1 samples presented coverage for pfhrp2 and pfhrp3. Genotyping of drug resistance markers showed a high prevalence of Chloroquine resistance mutations S1034C/N1042D/D1246Y in pfmdr1 (62.5%) and K45T in pfcrt (87.5%). Mutations associated with sulfadoxine and pyrimethamine treatment failure were found on 88.8% of the Bv1 samples which were triple mutants for pfdhfr (50R/51I/108N) and pfdhps (437G/540E/581G). Analysis of the pfS47 gene that allows P. falciparum to evade mosquito immune responses showed that the Bv1 lineage presented one pfS47 haplotype exclusive to Loreto and another haplotype that was present in both Loreto and Tumbes. Furthermore, a possible expansion of Bv1 was detected since 2011 in Loreto. This replacement could be a result of the high prevalence of CQ resistance polymorphisms in Bv1, which could have provided a selective advantage to the indirect selection pressures driven by the use of CQ for P. vivax treatment.
Topics: Antiprotozoal Agents; Chloroquine; Drug Resistance; Evolution, Molecular; Gene Frequency; Genome, Protozoan; Mosquito Vectors; Peru; Plasmodium falciparum; Polymorphism, Single Nucleotide; Pyrimethamine; Sulfadoxine
PubMed: 34707204
DOI: 10.1038/s41598-021-00806-5 -
Lancet (London, England) Apr 2019Intermittent treatment with sulfadoxine-pyrimethamine, recommended for prevention of malaria in pregnant women throughout sub-Saharan Africa, is threatened by parasite... (Comparative Study)
Comparative Study Randomized Controlled Trial
Monthly sulfadoxine-pyrimethamine versus dihydroartemisinin-piperaquine for intermittent preventive treatment of malaria in pregnancy: a double-blind, randomised, controlled, superiority trial.
BACKGROUND
Intermittent treatment with sulfadoxine-pyrimethamine, recommended for prevention of malaria in pregnant women throughout sub-Saharan Africa, is threatened by parasite resistance. We assessed the efficacy and safety of intermittent preventive treatment with dihydroartemisinin-piperaquine as an alternative to sulfadoxine-pyrimethamine.
METHODS
We did a double-blind, randomised, controlled, superiority trial at one rural site in Uganda with high malaria transmission and sulfadoxine-pyrimethamine resistance. HIV-uninfected pregnant women between 12 and 20 weeks gestation were randomly assigned (1:1) to monthly intermittent preventive treatment during pregnancy with sulfadoxine-pyrimethamine or dihydroartemisinin-piperaquine. The primary endpoint was the risk of a composite adverse birth outcome defined as low birthweight, preterm birth, or small for gestational age in livebirths. Protective efficacy was defined as 1-prevalence ratio or 1-incidence rate ratio. All analyses were done by modified intention to treat. This trial is registered with ClinicalTrials.gov, number NCT02793622.
FINDINGS
Between Sept 6, 2016, and May 29, 2017, 782 women were enrolled and randomly assigned to receive sulfadoxine-pyrimethamine (n=391) or dihydroartemisinin-piperaquine (n=391); 666 (85·2%) women who delivered livebirths were included in the primary analysis. There was no significant difference in the risk of our composite adverse birth outcome between the dihydroartemisinin-piperaquine and sulfadoxine-pyrimethamine treatment group (54 [16%] of 337 women vs 60 [18%] of 329 women; protective efficacy 12% [95% CI -23 to 37], p=0·45). Both drug regimens were well tolerated, with no significant differences in adverse events between the groups, with the exception of asymptomatic corrected QT interval prolongation, which was significantly higher in the dihydroartemisinin-piperaquine group (mean change 13 ms [SD 23]) than in the sulfadoxine-pyrimethamine group (mean change 0 ms [SD 23]; p<0·0001).
INTERPRETATION
Monthly intermittent preventive treatment with dihydroartemisinin-piperaquine was safe but did not lead to significant improvements in birth outcomes compared with sulfadoxine-pyrimethamine.
FUNDING
Eunice Kennedy Shriver National Institute of Child Health and Human Development, and Bill & Melinda Gates Foundation.
Topics: Adult; Antimalarials; Artemisinins; Double-Blind Method; Drug Administration Schedule; Drug Combinations; Drug Therapy, Combination; Female; Humans; Malaria, Falciparum; Pregnancy; Pregnancy Complications, Parasitic; Pregnancy Outcome; Pyrimethamine; Quinolines; Sulfadoxine; Uganda; Young Adult
PubMed: 30910321
DOI: 10.1016/S0140-6736(18)32224-4 -
Maternal & Child Nutrition Dec 2015Folic acid and iron supplementation has historically been recommended as the preferred anaemia control strategy among preschoolers in sub-Saharan Africa and other... (Review)
Review
Folic acid and iron supplementation has historically been recommended as the preferred anaemia control strategy among preschoolers in sub-Saharan Africa and other resource-poor settings, but home fortification of complementary foods with multiple micronutrient powders (MNPs) can now be considered the preferred approach. The World Health Organization endorses home fortification with MNPs containing at least iron, vitamin A and zinc to control childhood anaemia, and calls for concomitant malaria control strategies in malaria endemic regions. Among other micronutrients, current MNP formulations generally include 88 μg folic acid (corresponding to 100% of the Recommended Nutrient Intake). The risks and benefits of providing supplemental folic acid at these levels are unclear. The limited data available indicate that folate deficiency may not be a major public health problem among children living in sub-Saharan Africa and supplemental folic acid may therefore not have any benefits. Furthermore, supraphysiological, and possibly even physiological, folic acid dosages may favour Plasmodium falciparum growth, inhibit parasite clearance of sulphadoxine-pyrimethamine (SP)-treated malaria and increase subsequent recrudescence. Even though programmatic options to limit prophylactic SP use or to promote the use of insecticide treated bed nets may render the use of folic acid safer, programmatic barriers to these approaches are likely to persist. Research is needed to characterise the prevalence of folate deficiency among young children worldwide and to design safe MNP and other types of fortification approaches in sub-Sahara Africa. In parallel, updated global guidance is needed for MNP programmes in these regions.
Topics: Africa South of the Sahara; Antimalarials; Child, Preschool; Dietary Supplements; Dose-Response Relationship, Drug; Drug Combinations; Folic Acid; Folic Acid Deficiency; Food, Fortified; Humans; Infant; Iron, Dietary; Malaria; Micronutrients; Nutritional Requirements; Observational Studies as Topic; Plasmodium falciparum; Powders; Prevalence; Pyrimethamine; Randomized Controlled Trials as Topic; Recommended Dietary Allowances; Sulfadoxine; Vitamin A; Zinc
PubMed: 26756732
DOI: 10.1111/mcn.12102 -
Tropical Medicine & International... Sep 2014Cotrimoxazole prophylactic treatment (CPT) prevents opportunistic infections in HIV-infected or HIV-exposed children, but estimates of the effectiveness in preventing... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Cotrimoxazole prophylactic treatment (CPT) prevents opportunistic infections in HIV-infected or HIV-exposed children, but estimates of the effectiveness in preventing malaria vary. We reviewed studies that examined the effect of CPT on incidence of malaria in children in sub-Saharan Africa.
METHODS
We searched PubMed and EMBASE for randomised controlled trials (RCTs) and cohort studies on the effect of CPT on incidence of malaria and mortality in children and extracted data on the prevalence of sulphadoxine-pyrimethamine resistance-conferring point mutations. Incidence rate ratios (IRR) from individual studies were combined using random effects meta-analysis; confounder-adjusted estimates were used for cohort studies. The importance of resistance was examined in meta-regression analyses.
RESULTS
Three RCTs and four cohort studies with 5039 children (1692 HIV-exposed; 2800 HIV-uninfected; 1486 HIV-infected) were included. Children on CPT were less likely to develop clinical malaria episodes than those without prophylaxis (combined IRR 0.37, 95% confidence interval: 0.21-0.66), but there was substantial between-study heterogeneity (I-squared = 94%, P < 0.001). The protective efficacy of CPT was highest in an RCT from Mali, where the prevalence of antifolate resistant plasmodia was low. In meta-regression analyses, there was some evidence that the efficacy of CPT declined with increasing levels of resistance. Mortality was reduced with CPT in an RCT from Zambia, but not in a cohort study from Côte d'Ivoire.
CONCLUSIONS
Cotrimoxazole prophylactic treatment reduces incidence of malaria and mortality in children in sub-Saharan Africa, but study designs, settings and results were heterogeneous. CPT appears to be beneficial for HIV-infected and HIV-exposed as well as HIV-uninfected children.
Topics: Africa South of the Sahara; Antimalarials; Child; Drug Combinations; Drug Resistance; HIV Infections; Humans; Malaria; Mutation; Pyrimethamine; Sulfadoxine; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 25039469
DOI: 10.1111/tmi.12352 -
Acta Tropica Sep 2018Currently, the national malaria control programme (NMCP) of Sierra Leone recommends artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) as first- and...
Efficacy of artemisinin-based combination therapies and prevalence of molecular markers associated with artemisinin, piperaquine and sulfadoxine-pyrimethamine resistance in Sierra Leone.
Currently, the national malaria control programme (NMCP) of Sierra Leone recommends artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) as first- and second-line treatment for uncomplicated malaria, respectively, and artesunate + sulfadoxine-pyrimethamine (SP) for intermittent preventive treatment during pregnancy and for infants. In 2016, the NMCP conducted a study to assess the clinical and parasitological responses of children under five years to ASAQ, AL and dihydroartemisinin-piperaquine (DHA/PPQ) according to the WHO protocol. Day-0 samples were tested for mutations in the Kelch 13 gene (pfk13) and dihydrofolate reductase/dihydropteroate synthase (pfdhfr/pfdhps) genes associated with artemisinin and SP resistance, respectively, and amplification in the pfplasmepsin2 gene for piperaquine resistance. A total of 295 (ASAQ = 128, AL = 64 and DHA/PPQ = 103) eligible children were enrolled at three sites. PCR-corrected 100% adequate clinical and parasitological response and no parasitaemia on day-3 were observed for all patients in each treatment group. Of the 278 samples with interpretable molecular data, only 2.2% carried non-synonymous pfk13 mutants (A578S, I646T), which are not associated with artemisinin resistance. None of the 103 day-0 samples from the DAH/PPQ group had pfplasmepsin2 gene amplification, confirming the absence of piperaquine resistance. The prevalence of the triple pfdhfr mutant (N51I/C59R/S108N) was close to or reached fixation (97.4-100%). For combined pfdhfr/pfdhps mutation, 55-71% carried the quadruple (N51I/C59R/S108N+A437G) mutant and about 10% the quintuple mutant N51I/C59R/S108N+A437G/K540E. Our findings confirm that ASAQ, AL and DHA/PPQ were highly effective for the treatment of uncomplicated malaria in the study areas, and neither pfk13 validated mutations nor pfplasmepsin2 multiple copies were found. The very low prevalence of the quintuple mutant in this study supports the NMCP's decision to introduce intermittent preventive treatment for infants with SP in the districts with high malaria transmission.
Topics: Antimalarials; Artemisinins; Child, Preschool; Drug Resistance; Drug Therapy, Combination; Female; Humans; Infant; Malaria; Male; Mutation; Quinolines; Sulfadoxine; Tetrahydrofolate Dehydrogenase
PubMed: 29932931
DOI: 10.1016/j.actatropica.2018.06.016