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Praziquantel alone is insufficient for the control of schistosomiasis due to poor efficacy against juvenile worms and increasing concerns about the risk of drug resistance. We compared the efficacy and safety of praziquantel combined with four different artemisinin-based combinations to praziquantel alone in treating Schistosoma mansoni infection in Kenyan children. In this randomized, open-label, five-arm, head-to-head, non-inferiority trial, children (aged 9-15 years) with S. mansoni infection according to duplicate Kato Katz thick smears from a stool sample in the Mwea irrigation scheme of central Kenya, were enrolled. Participants were randomly assigned (1:1:1:1:1) via a computer-generated block randomization procedure to receive a single oral dose of praziquantel (PZQ) (40 mg/kg/day) alone or in combination with a 3-day course (4 mg/kg of artesunate) of artesunate plus sulfalene-pyrimethamine (As + SP), artesunate plus amodiaquine (As + AQ), artesunate plus mefloquine (As + MQ) or dihydroartemisinin-piperaquine (DHAP). Laboratory technicians were masked to treatment allocation, but participants, clinicians, and study nurses were not. The primary outcomes were the cure rate and frequency of adverse events, which were assessed 6 weeks after treatment in the available case population using a per-protocol analysis. The non-inferiority margin was set at -10% for the risk difference in cure rates between combination therapy and PZQ alone. Between 12 September 2018 and 11 January 2019, 540 participants were assigned to receive PZQ alone ( n = 108), PZQ plus As + SP ( n = 108), PZQ plus As + AQ ( n = 108), PZQ plus As + MQ ( n = 108), or PZQ plus DHAP ( n = 108). Primary outcome data were available for 523 (96.9%) participants. The cure rate was 82.5% (85/103) in PZQ alone, 81.7% (85/104) in PZQ plus As + SP, 76.2% (80/105) in PZQ plus As + AQ, 88.7% (94/106) in PZQ plus As + MQ, and 85.7% (90/105) in PZQ plus DHAP arm. Non-inferiority was declared for PZQ plus As + MQ (difference 6.2 [95% confidence interval: -3.3 to 15.6]) and PZQ plus DHAP (3.2 [-6.7 to 13.1]) but not for PZQ plus As + SP (-0.8 [-11.2 to 9.6]) or PZQ plus As + AQ (-6.3 [-17.3 to 4.6]). Adverse events were reported by 26% (138/540) of participants, including abdominal pain, headache, and vomiting. There were no serious adverse events. Alternatives to praziquantel should include praziquantel plus artesunate-mefloquine or praziquantel plus dihydroartemisinin-piperaquine. However, further multicentre trials are needed in different epidemiological settings and population groups to confirm these findings.CLINICAL TRIALSThis study is registered with the Pan-African Clinical Trials Registry under PACTR202001919442161., Competing Interests: The authors declare no conflict of interest.

Background: Triple artemisinin-based combination therapies (TACTs) can delay the spread of antimalarial drug resistance. Artesunate-amodiaquine is widely used for uncomplicated Plasmodium falciparum malaria. We therefore aimed to determine the safety and efficacy of artemether-lumefantrine-amodiaquine and artesunate-amodiaquine with and without single low-dose primaquine for reducing gametocyte carriage and transmission to mosquitoes., Methods: We did a five-arm, single-blind, phase 2 randomised controlled trial at the Ouélessébougou Clinical Research Unit of the Malaria Research and Training Centre of the University of Sciences, Techniques and Technologies of Bamako in Mali. Eligible participants were aged 10-50 years, with asymptomatic P falciparum microscopy-detected gametocyte carriage. Eligible participants were randomly allocated (1:1:1:1:1) to receive either artemether-lumefantrine, artemether-lumefantrine-amodiaquine, artemether-lumefantrine-amodiaquine plus primaquine, artesunate-amodiaquine, or artesunate-amodiaquine plus primaquine. Treatment regimens were administered on days 0, 1, and 2; primaquine was given as a single dose on day 0. All staff except the trial pharmacist and participants were masked to the treatment allocation. The primary outcome was the median percentage change in mosquito infection rate between pretreatment and 2 days after treatment initiation, assessed by direct membrane feeding assay. Data were analysed using a per-protocol analysis. This study is registered with ClinicalTrials.gov, NCT05550909., Findings: Between Oct 16, 2022, and Dec 28, 2022, a total of 1249 individuals were screened; of whom, 100 were enrolled and randomly assigned to one of the five treatment groups (20 per group). Before treatment, 61 (61%) of 100 participants were infectious to mosquitoes, with a median of 7·3% (IQR 3·2 to 23·5) of mosquitoes becoming infected. Among infectious participants, the median percentage reduction in mosquito infection rate between pretreatment and 2 days after treatment was 100% (IQR 100 to 100) in the artemether-lumefantrine (p=0·0018), artemether-lumefantrine-amodiaquine (p=0·0018), and artemether-lumefantrine-amodiaquine plus primaquine (p=0·0009) treatment groups. In the artesunate-amodiaquine group the median percentage reduction in mosquito infection rate was only 32% (IQR -10·9 to 79·4; p=0·19), whereas a 100% median reduction was seen in the artesunate-amodiaquine plus primaquine group (IQR 100 to 100; p=0·0009). At day 2, two (10%) of 20 participants in the artemether-lumefantrine group, two (11%) of 19 in the artemether-lumefantrine-amodiaquine group, and 15 (75%) of 20 in the artesunate-amodiaquine group infected any number of mosquitoes whereas no infected mosquitoes were observed at this timepoint in the groups with primaquine. 85 (85%) of 100 participants had a total of 262 adverse events during follow-up; of which, 181 (69%) were categorised as mild and 81 (31%) as moderate. No serious adverse events were reported., Interpretation: Our findings support the effectiveness of artemether-lumefantrine alone or as part of TACT for preventing nearly all human-mosquito malaria parasite transmission within 48 h. By contrast, substantial transmission was observed following treatment with artesunate-amodiaquine. The addition of a single low dose of primaquine blocks transmission to mosquitoes rapidly regardless of schizonticide., Funding: Bill & Melinda Gates Foundation., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Several interventional strategies have been implemented in malaria endemic areas where the burden is high, that include among others, intermittent preventive treatment (IPT), a tactic that blocks transmission and can reduce disease morbidity. However, the implementation IPT strategies raises a genuine concern, intervening the development of naturally acquired immunity to malaria which requires continuous contact with parasite antigens. This study investigated whether dihydroartemisinin-piperaquine (DP) or artesunate-amodiaquine (ASAQ) IPT in schoolchildren (IPTsc) impairs IgG reactivity to six malaria antigens. An IPTsc trial in north-eastern Tanzania administered three doses of DP or ASAQ at four-monthly intervals and the schoolchildren were followed up. This study compared IgG reactivity against GLURP-R2, MSP1, MSP3, and CIDR domains (CIDRa1.1, CIDRa1.4, and CIDRa1.5) of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP-1) in intervention and control groups using enzyme linked immunosorbent assay (ELISA) technique. During the study, 369 schoolchildren were available for analysis, 119, 134 and 116 participants in the control, DP and ASAQ groups, respectively. Breadth of malaria antigen recognition increased significantly during and after the intervention phases and did not differ between the study groups (Trend test: DP, z-score = 5.92, p < 0.001, ASAQ, z-score = 6.64, p < 0.001 and control, z-score = 5.85, p < 0.001). There were no differences between the control and ASAQ group in the recognition of any of the tested antigens at all visits. In the DP group, however, during the intervention period IPTsc did not impair antibody against MSP1, MSP3, CIDRa1.1, CIDRa1.4 and CIDRa1.5, but it did impair against GLURP-R2. The current study has shown that effective IPTsc with DP or ASAQ does not interfere with the development of antibodies against malaria antigens of the blood stages, suggesting that the advancement of naturally acquired immunity to malaria is not impeded by IPTsc interventions., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Lyimo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: In 2021, nationwide malaria molecular surveillance revealed a high prevalence of a validated artemisinin resistance marker, the kelch13 (k13) Arg561His mutation, in the Kagera region of northwestern Tanzania. We aimed to investigate the efficacy of artemether-lumefantrine and artesunate-amodiaquine and to confirm the presence of artemisinin partial resistance (ART-R) in the Karagwe district of this region., Methods: This single-arm, therapeutic efficacy study was carried out at the Bukangara dispensary in the Karagwe district of the Kagera region in northwestern Tanzania. Eligible participants were aged between 6 months and 120 months, had confirmed Plasmodium falciparum asexual parasitaemia, and met other inclusion criteria according to WHO's standard protocol. Participants were enrolled, treated sequentially with either artemether-lumefantrine or artesunate-amodiaquine, and assessed clinically and parasitologically for 28 days as per WHO protocol. Parasitaemia was measured every 8 h until day 3, on day 7, and then during weekly follow-up visits until day 28. Mutations in the k13 gene and extended haplotypes with the mutations were analysed, and comparisons were made with previous samples collected in the same region of Kagera and in Rwanda and southeast Asia. The primary endpoint was PCR-corrected cure rate., Findings: Between April 29 and Sept 1, 2022, 343 patients were screened, of whom 176 were enrolled: 88 in each treatment group. The PCR-corrected cure rate was 98% (95% CI 91-100) in the artemether-lumefantrine group and 100% (96-100) in the artesunate-amodiaquine group. Persistent parasitaemia on day 3 occurred in 11 (13%) of 88 patients in the artemether-lumefantrine group and 17 (19%) of 88 patients in the artesunate-amodiaquine group. Arg561His mutations on day 0 and parasitaemia on day 3 were reported in eight (9%) of 87 patients in the artemether-lumefantrine group and ten (12%) of 86 patients in the artesunate-amodiaquine group. The median parasite clearance half-life in patients harbouring parasites with Arg561His mutation was 6·1 h in the artemether-lumefantrine group and 6·0 h in the artesunate-amodiaquine group. Parasites with the Arg561His mutation were not similar to those from southeast Asia and Rwanda but had similar haplotypes to parasites reported in the same Tanzanian region of Kagera in 2021., Interpretation: This study confirms the presence of ART-R in Tanzania, although artemether-lumefantrine and artesunate-amodiaquine showed high efficacy. A context-specific response strategy and vigilance to detect the reduced efficacy of current antimalarial treatments and ART-R in other parts of the country are urgently needed., Funding: The Bill & Melinda Gates Foundation and the US National Institutes of Health., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Artemisinin-based combination therapy (ACT) is the first-line recommended treatment for uncomplicated malaria. Pharmacokinetic (PK) properties in pregnant women are often based on small studies and need to be confirmed and validated in larger pregnant patient populations. This study aimed to evaluate the PK properties of amodiaquine and its active metabolite, desethylamodiaquine, and piperaquine in women in their second and third trimester of pregnancy with uncomplicated P. falciparum infections. Eligible pregnant women received either artesunate-amodiaquine (200/540 mg daily, n = 771) or dihydroartemisinin-piperaquine (40/960 mg daily, n = 755) for 3 days (NCT00852423). Population PK properties were evaluated using nonlinear mixed-effects modeling, and effect of gestational age and trimester was evaluated as covariates. 1071 amodiaquine and 1087 desethylamodiaquine plasma concentrations, and 976 piperaquine plasma concentrations, were included in the population PK analysis. Amodiaquine concentrations were described accurately with a one-compartment disposition model followed by a two-compartment disposition model of desethylamodiaquine. The relative bioavailability of amodiaquine increased with gestational age (1.25% per week). The predicted exposure to desethylamodiaquine was 2.8%-32.2% higher in pregnant women than that reported in non-pregnant women, while day 7 concentrations were comparable. Piperaquine concentrations were adequately described by a three-compartment disposition model. Neither gestational age nor trimester had significant impact on the PK of piperaquine. The predicted exposure and day 7 concentrations of piperaquine were similar to that reported in non-pregnant women. In conclusion, the exposure to desethylamodiaquine and piperaquine was similar to that in non-pregnant women. Dose adjustment is not warranted for women in their second and their trimester of pregnancy., (© 2024 The Author(s). CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Objective: Intermittent Preventive Treatment of schoolchildren (IPTsc) is recommended by WHO as a strategy to protect against malaria; to explore whether IPTsc with dihydroartemisinin-piperaquine (DP) or artesunate-amodiaquine (ASAQ) cause a selection of molecular markers in Plasmodium falciparum genes associated with resistance in children in seven schools in Tanga region, Tanzania., Methods: SNPs in P. falciparum genes Pfmdr1, Pfexo, Pfkelch13, and Pfcrt and copy number variations in Pfplasmepsin-2 and Pfmdr1 were assessed in samples collected at 12 months (visit 4, n=74) and 20 months (visit 6, n=364) after initiation of IPTsc and compared with the baseline prevalence (n=379)., Results: The prevalence of Pfmdr1 N86 and Pfexo 415G was >99% and 0%, respectively without any temporal differences observed. The prevalence of Pfmdr1 184F changed significantly from baseline (52.2%) to visit 6 (64.6%) (χ 2 =6.11, P=0.013), but no differences were observed between the treatment arms (χ 2 =0.05, P=0.98). Finally, only minor differences in the amplification of Pfmdr1 were observed; from 10.2% at baseline to 16.7% at visit 6 (χ 2 =0.98, P=0.32)., Conclusions: The IPTsc strategy does not seem to pose a risk for the selection of markers associated with DP or ASAQ resistance. Continuously and timely surveillance of markers of antimalarial drug resistance is recommended., Competing Interests: Declarations of competing interest No conflicts by any of the authors., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Artemisinin-based combination therapy (ACT) has been a major contributor to the substantial reductions in global malaria morbidity and mortality over the last decade. In Tanzania, artemether-lumefantrine (AL) was introduced as the first-line treatment for uncomplicated Plasmodium falciparum malaria in 2006. The World Health Organization (WHO) recommends regular assessment and monitoring of the efficacy of the first-line treatment, specifically considering that artemisinin resistance has been confirmed in the Greater Mekong sub-region. This study's main aim was to assess the efficacy and safety of AL for treating uncomplicated P. falciparum malaria in Tanzania., Methods: This was a single-arm prospective antimalarial drug efficacy trial conducted in four of the eight National Malaria Control Programme (NMCP) sentinel sites in 2019. The trial was carried out in outpatient health facilities in Karume-Mwanza region, Ipinda-Mbeya region, Simbo-Tabora region, and Nagaga-Mtwara region. Children aged six months to 10 years with microscopy confirmed uncomplicated P. falciparum malaria who met the inclusion criteria were recruited based on the WHO protocol. The children received AL (a 6-dose regimen of AL twice daily for three days). Clinical and parasitological parameters were monitored during follow-up over 28 days to evaluate drug efficacy., Results: A total of 628 children were screened for uncomplicated malaria, and 349 (55.6%) were enrolled between May and September 2019. Of the enrolled children, 343 (98.3%) completed the 28-day follow-up or attained the treatment outcomes. There were no early treatment failures; recurrent infections during follow-up were common at two sites (Karume 29.5%; Simbo 18.2%). PCR-corrected adequate clinical and parasitological response (ACPR) by survival analysis to AL on day 28 of follow-up varied from 97.7% at Karume to 100% at Ipinda and Nagaga sites. The commonly reported adverse events were cough, skin pallor, and abdominal pain. The drug was well tolerated, and no serious adverse event was reported., Conclusion: This study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria in Tanzania in 2019. The high recurrent infections were mainly due to new infections, highlighting the potential role of introducing alternative artemisinin-based combinations that offer improved post-treatment prophylaxis, such as artesunate-amodiaquine (ASAQ)., (© 2024. The Author(s).)

Background: The use of artemisinin-based combination therapy (ACT) is recommended by the World Health Organization for the treatment of uncomplicated falciparum malaria. Artemether-lumefantrine (AL) is the most widely adopted first-line ACT for uncomplicated malaria in sub-Saharan Africa (SSA), including mainland Tanzania, where it was introduced in December 2006. The WHO recommends regular assessment to monitor the efficacy of the first-line treatment specifically considering that artemisinin partial resistance was reported in Greater Mekong sub-region and has been confirmed in East Africa (Rwanda and Uganda). The main aim of this study was to assess the efficacy and safety of AL for the treatment of uncomplicated falciparum malaria in mainland Tanzania., Methods: A single-arm prospective anti-malarial drug efficacy trial was conducted in Kibaha, Mlimba, Mkuzi, and Ujiji (in Pwani, Morogoro, Tanga, and Kigoma regions, respectively) in 2018. The sample size of 88 patients per site was determined based on WHO 2009 standard protocol. Participants were febrile patients (documented axillary temperature ≥ 37.5 °C and/or history of fever during the past 24 h) aged 6 months to 10 years. Patients received a 6-dose AL regimen by weight twice a day for 3 days. Clinical and parasitological parameters were monitored during 28 days of follow-up to evaluate the drug efficacy and safety., Results: A total of 653 children were screened for uncomplicated malaria and 349 (53.7%) were enrolled between April and August 2018. Of the enrolled children, 345 (98.9%) completed the 28 days of follow-up or attained the treatment outcomes. There were no early treatment failures, but recurrent infections were higher in Mkuzi (35.2%) and Ujiji (23%). By Kaplan-Meier analysis of polymerase chain reaction (PCR) uncorrected adequate clinical and parasitological response (ACPR) ranged from 63.4% in Mkuzi to 85.9% in Mlimba, while PCR-corrected ACPR on day 28 varied from 97.6% in Ujiji to 100% in Mlimba. The drug was well tolerated; the commonly reported adverse events were cough, runny nose, and abdominal pain. No serious adverse event was reported., Conclusion: This study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria. The high number of recurrent infections were mainly due to new infections, indicating the necessity of utilizing alternative artemisinin-based combinations, such as artesunate amodiaquine, which provide a significantly longer post-treatment prophylactic effect., (© 2024. The Author(s).)

Monitoring antimalarial efficacy is important to detect the emergence of parasite drug resistance. Angola conducts in vivo therapeutic efficacy studies (TESs) every 2 years in its fixed sentinel sites in Benguela, Lunda Sul, and Zaire provinces. Children with uncomplicated Plasmodium falciparum malaria were treated with artemether-lumefantrine (AL), artesunate-amodiaquine (ASAQ), dihydroartemisinin-piperaquine (DP), or artesunate-pyronaridine (ASPY) and followed for 28 (AL and ASAQ) or 42 days (DP and ASPY) to assess clinical and parasitological response to treatment. Two drugs were sequentially assessed in each site in February-July 2021. The primary indicator was the Kaplan-Meier estimate of the PCR-corrected efficacy at the end of the follow-up period. A total of 622 patients were enrolled in the study and 590 (95%) participants reached a study endpoint. By day 3, ≥98% of participants were slide-negative in all study sites and arms. After PCR correction, day 28 AL efficacy was 88.0% (95% CI: 82%-95%) in Zaire and 94.7% (95% CI: 90%-99%) in Lunda Sul. For ASAQ, day 28 efficacy was 92.0% (95% CI: 87%-98%) in Zaire and 100% in Lunda Sul. Corrected day 42 efficacy was 99.6% (95% CI: 99%-100%) for ASPY and 98.3% (95% CI: 96%-100%) for DP in Benguela. High day 3 clearance rates suggest no clinical evidence of artemisinin resistance. This was the fourth of five rounds of TES in Angola showing a corrected AL efficacy <90% in a site. For Zaire, AL has had an efficacy <90% in 2013, 2015, and 2021. ASAQ, DP, and ASPY are appropriate choices as artemisinin-based combination therapies in Angola., Competing Interests: The authors declare no conflict of interest.

Introduction: Polymorphonuclear neutrophils (PMN) are involved in pathogen clearance by phagocytosis. However, the role of PMNs in the efficacy of artemisinin-based combination therapy (ACT) is poorly understood., Methodology: In a prospective longitudinal in vivo study, neutrophil rates were compared with malaria carriage after treatment with different ACTs: Artemether - lumefantrine (AL), Artesunate - amodiaquine (ASAQ), Dihydroartemisinin - piperaquine (DP) or Pyronaridine artesunate (PA). The study cases were classified as having neutropenia, normal neutrophil levels or neutrophilia depending on the level of neutrophils in the blood. This study included 3148 patients and was analyzed using R., Results: On day 7, only four patients in the neutropenia group and treated with AL had a malaria positive blood smear based on microscopy. On day 28, the rate of recurrent parasitemia in the AL arm was significantly higher in neutropenia patients (50.9%) than in patients with normal rates of neutrophils (43.1%) or in those with neutrophilia (6.0%) (p < 0.001). In ASAQ arm, the rate of recurrent Plasmodium falciparum parasitemia was 58.8% in the neutropenia group versus 29.4% in patients with normal rates of neutrophils and 11.8% in patients with neutrophilia (p < 0.001). No patient treated with DP with normal neutrophil counts or neutrophilia was carrying malaria parasites on day 28. Among the 15 patients with parasitemia on day 28 in the PA arm, 11 (73.33%) had neutropenia while 4 (26.67%) had a normal neutrophil count (p < 0.001)., Conclusions: Patients with neutropenia had higher rates of recurrent P. falciparum parasitemia after ACT., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2023 Moussa Djimde, Kassoum Kayentao, Japhet Kabalu Tshiongo, Bakary Fofana, Charles Arama, Sodiomon B Sirima, Jean Bosco Ouedraogo, Abdoul Habib Beavogui, Issaka Sagara, Alassane Dicko, Petra F Mens, Henk DFH Schallig, Abdoulaye Djimde.)

Background: Artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) are the currently recommended first-and second-line therapies for uncomplicated Plasmodium falciparum infections in Chad. This study assessed the efficacy of these artemisinin-based combinations, proportion of day 3 positive patients, proportions of molecular markers associated with P. falciparum resistance to anti-malarial drugs and variable performance of HRP2-based malaria rapid diagnostic tests (RDTs)., Methods: A single-arm prospective study assessing the efficacy of AS-AQ and AL at three sites (Doba, Kelo and Koyom) was conducted between November 2020 to January 2021. Febrile children aged 6 to 59 months with confirmed uncomplicated P. falciparum infection were enrolled sequentially first to AS-AQ and then AL at each site and followed up for 28 days. The primary endpoint was PCR-adjusted adequate clinical and parasitological response (ACPR). Samples collected on day 0 were analysed for mutations in pfkelch13, pfcrt, pfmdr-1, pfdhfr, pfdhps genes and deletions in pfhrp2/pfhrp3 genes., Results: By the end of 28-day follow-up, per-protocol PCR corrected ACPR of 97.8% (CI 95% 88.2-100) in Kelo and 100% in Doba and Kayoma were observed among AL treated patients. For ASAQ, 100% ACPR was found in all sites. All, but one patient, did not have parasites detected on day 3. Out of the 215 day 0 samples, 96.7% showed pfkelch13 wild type allele. Seven isolates carried nonsynonymous mutations not known to be associated artemisinin partial resistance (ART-R). Most of samples had a pfcrt wild type allele (79% to 89%). The most prevalent pfmdr-1 allele detected was the single mutant 184F (51.2%). For pfdhfr and pfdhps mutations, the quintuple mutant allele N51I/C59R/S108N + G437A/540E responsible for SP treatment failures in adults and children was not detected. Single deletion in the pfhrp2 and pfhrp3 gene were detected in 10/215 (4.7%) and 2/215 (0.9%), respectively. Dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, were observed in 5/215 (2.3%) isolates., Conclusion: The results of this study confirm that AS-AQ and AL treatments are highly efficacious in study areas in Chad. The absence of known pfkelch13 mutations in the study sites and the high parasite clearance rate at day 3 suggest the absence of ART-R. The absence of pfdhfr/pfdhps quintuple or sextuple (quintuple + 581G) mutant supports the continued use of SP for IPTp during pregnancy. The presence of parasites with dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, warrants the continued surveillance. Trial registration ACTRN12622001476729., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Artemisinin-based combination therapy (ACT) is the most effective treatment for malaria, and has significantly reduced morbimortality. Polymorphisms associated with the Plasmodium falciparum Kelch gene (Pfkelch13) have been associated with delayed parasite clearance even with ACT treatment., Methods: The Pfkelch13 gene was sequenced from P. falciparum infected patients (n = 159) with uncomplicated malaria in Niger. An adequate clinical and parasitological response (ACPR) was reported in 155 patients. Four (n = 4) patients had treatment failure (TF) that were not reinfections-two of which had late parasitological failures (LPF) and two had late clinical failures (LCF)., Results: Thirteen single nucleotide polymorphisms (SNPs) were identified of which seven were non-synonymous (C469R, T508S, R515T, A578S, I465V, I437V, F506L,), and three were synonymous (P443P, P715P, L514L). Three SNP (C469R, F506L, P715P) were present before ACT treatment, while seven mutations (C469R, T508S, R515T, L514L, P443P, I437V, I465V) were selected by artemether/lumefantrine (AL)-five of which were non-synonymous (C469R, T508S, R515T, I437V, I465V). Artesunate/amodiaquine (ASAQ) has selected any mutation. One sample presented three cumulatively non-synonymous SNPs-C469R, T508S, R515T., Conclusions: This study demonstrates intra-host selection of Pfkelch13 gene by AL. The study highlights the importance of LCF and LPF parasites in the selection of resistance to ACT. Further studies using gene editing are required to confirm the potential implication of resistance to ACT with the most common R515T and T508S mutations. It would also be important to elucidate the role of cumulative mutations., (© 2023. The Author(s).)

This article highlights over a decade of signature achievements by the West Africa International Centers for Excellence in Malaria Research (WA-ICEMR) and its partners toward guiding malaria prevention and control strategies. Since 2010, the WA-ICEMR has performed longitudinal studies to monitor and assess malaria control interventions with respect to space-time patterns, vector transmission indicators, and drug resistance markers. These activities were facilitated and supported by the Mali National Malaria Control Program. Research activities included large-scale active and passive surveillance and expanded coverage of universal long-lasting insecticide-treated bed nets and seasonal malaria chemoprevention (SMC). The findings revealed substantial declines in malaria occurrence after the scale-up of control interventions in WA-ICEMR study sites. WA-ICEMR studies showed that SMC using sulfadoxine-pyrimethamine plus amodiaquine was highly effective in preventing malaria among children under 5 years of age. An alternative SMC regimen (dihydroartemisinin plus piperaquine) was shown to be potentially more effective and provided advantages for acceptability and compliance over the standard SMC regimen. Other findings discussed in this article include higher observed multiplicity of infection rates for malaria in historically high-endemic areas, continued antimalarial drug sensitivity to Plasmodium falciparum, high outdoor malaria transmission rates, and increased insecticide resistance over the past decade. The progress achieved by the WA-ICEMR and its partners highlights the critical need for maintaining current malaria control interventions while developing novel strategies to disrupt malaria transmission. Enhanced evaluation of these strategies through research partnerships is particularly needed in the wake of reported artemisinin resistance in Southeast Asia and East Africa.

Background: Children with sickle cell anemia (SCA) in areas of Africa with endemic malaria transmission are commonly prescribed malaria chemoprevention. Chemoprevention regimens vary between countries, and the comparative efficacy of prevention regimens is largely unknown., Methods and Findings: We enrolled Kenyan children aged 1 to 10 years with homozygous hemoglobin S (HbSS) in a randomized, open-label trial conducted between January 23, 2018, and December 15, 2020, in Homa Bay, Kenya. Children were assigned 1:1:1 to daily Proguanil (the standard of care), monthly sulfadoxine/pyrimethamine-amodiaquine (SP-AQ), or monthly dihydroartemisinin-piperaquine (DP) and followed monthly for 12 months. The primary outcome was the cumulative incidence of clinical malaria at 12 months, and the main secondary outcome was the cumulative incidence of painful events by self-report. Secondary outcomes included other parasitologic, hematologic, and general events. Negative binomial models were used to estimate incidence rate ratios (IRRs) per patient-year (PPY) at risk relative to Proguanil. The primary analytic population was the As-Treated population. A total of 246 children were randomized to daily Proguanil (n = 81), monthly SP-AQ (n = 83), or monthly DP (n = 82). Overall, 53.3% (n = 131) were boys and the mean age was 4.6 ± 2.5 years. The clinical malaria incidence was 0.04 episodes/PPY; relative to the daily Proguanil group, incidence rates were not significantly different in the monthly SP-AQ (IRR: 3.05, 95% confidence interval [CI]: 0.36 to 26.14; p = 0.39) and DP (IRR: 1.36, 95% CI: 0.21 to 8.85; p = 0.90) groups. Among secondary outcomes, relative to the daily Proguanil group, the incidence of painful events was not significantly different in the monthly SP-AQ and DP groups, while monthly DP was associated with a reduced rate of dactylitis (IRR: 0.47; 95% CI: 0.23 to 0.96; p = 0.038). The incidence of Plasmodium falciparum infection relative to daily Proguanil was similar in the monthly SP-AQ group (IRR 0.46; 95% CI: 0.17 to 1.20; p = 0.13) but reduced with monthly DP (IRR 0.21; 95% CI: 0.08 to 0.56; p = 0.002). Serious adverse events were common and distributed between groups, although compared to daily Proguanil (n = 2), more children died receiving monthly SP-AQ (n = 7; hazard ratio [HR] 5.44; 95% CI: 0.92 to 32.11; p = 0.064) but not DP (n = 1; HR 0.61; 95% CI 0.04 to 9.22; p = 0.89), although differences did not reach statistical significance for either SP-AQ or DP. Study limitations include the unexpectedly limited transmission of P. falciparum in the study setting, the high use of hydroxyurea, and the enhanced supportive care for trial participants, which may limit generalizability to higher-transmission settings where routine sickle cell care is more limited., Conclusions: In this study with limited malaria transmission, malaria chemoprevention in Kenyan children with SCA with monthly SP-AQ or DP did not reduce clinical malaria, but DP was associated with reduced dactylitis and P. falciparum parasitization. Pragmatic studies of chemoprevention in higher malaria transmission settings are warranted., Trial Registration: clinicaltrials.gov (NCT03178643). Pan-African Clinical Trials Registry: PACTR201707002371165., Competing Interests: The authors have declared that no competing interests exist.

Intermittent preventive treatment of malaria among schoolchildren (IPTsc) reduces clinical malaria, asymptomatic parasitemia, and anemia. The effects of IPTsc by gender have not been studied longitudinally. We investigated overall IPTsc efficacy and conducted a secondary analysis to explore gender-specific differences. We enrolled schoolchildren aged 6-13 years in an open-label, rolling-cohort randomized controlled trial between September 2007 and February 2013 in Kolle, Mali. Annually, schoolchildren received two full-treatment courses of sulfadoxine-pyrimethamine (SP) plus artesunate, or amodiaquine (AQ) plus artesunate, or no malaria treatment as control. We used mixed-effects generalized linear models to estimate differences in treatment outcomes across groups with interaction terms to explore gender-specific differences associated with Plasmodium falciparum infection, hemoglobin, and grade point averages (GPA) based on standardized testing. Overall, 305 students contributed 4,564 observations. Compared with the control, SP plus artesunate and AQ plus artesunate reduced the odds of P. falciparum infection (odds ratio [OR]: 0.33, 95% CI: 0.26-0.43; OR: 0.46, 95% CI: 0.36-0.59). We found strong evidence of increased mean hemoglobin concentrations (g/dL) in the SP plus artesunate group versus control (difference +0.37, 95% CI: 0.13-0.58). Collectively, schoolchildren given AQ plus artesunate had higher mean GPA (difference +0.36, 95% CI: 0.02-0.69) relative to control. Schoolgirls, compared with schoolboys, given SP plus artesunate had greater improvement in GPA (+0.50, 95% CI: -0.02 to 1.02 versus -0.27, 95% CI: -0.71 to 0.16); interaction P = 0.048, respectively. The IPTsc decreases P. falciparum infections in schoolchildren. Treatment regimens that include longer-acting drugs may be more effective at decreasing malaria-related anemia and improving educational outcomes as observed among girls in this setting.

Background: In Burkina Faso, malaria remains the first cause of medical consultation and hospitalization in health centres. First-line case management of malaria in the country's health facilities is based on the use of artemisinin-based combination therapy (ACT). To optimize the use of these anti-malarial drugs in the perspective of mitigating the emergence of artemisinin resistance, which is a serious threat to malaria control and elimination, a pilot programme using multiple first-line therapies (MFTs) [three artemisinin-based combinations-pyronaridine-artesunate, dihydroartemisinin-piperaquine and artemether-lumefantrine] has been designed for implementation. As the success of this MFT pilot programme depends on the perceptions of key stakeholders in the health system and community members, the study aimed to assess their perceptions on the implementation of this strategy., Methods: Semi-structured interviews, including 27 individual in-depth interviews and 41 focus groups discussions, were conducted with key stakeholders including malaria control policymakers and implementers, health system managers, health workers and community members. Volunteers from targets stakeholder groups were randomly selected. All interviews were recorded, transcribed and translated. Content analysis was performed using the qualitative software programme QDA Miner., Results: The interviews revealed a positive perception of stakeholders on the implementation of the planned MFT programme. They saw the strategy as an opportunity to strengthen the supply of anti-malarial drugs and improve the management of fever and malaria. However, due to lack of experience with the products, health workers and care givers expressed some reservations about the effectiveness and side-effect profiles of the two anti-malarial drugs included as first-line therapy in the MFT programme (pyronaridine-artesunate, dihydroartemisinin-piperaquine). Questions were raised about the appropriateness of segmenting the population into three groups and assigning a specific drug to each group., Conclusion: The adherence of both populations and key stakeholders to the MFT implementation strategy will likely depend on the efficacy of the proposed drugs, the absence of, or low frequency of, side-effects, the cost of drugs and availability of the different combinations., (© 2022. The Author(s).)

Background: Late treatment failures after artemisinin-based combination therapies (ACTs) for falciparum malaria have increased in the Greater Mekong subregion in southeast Asia. Addition of amodiaquine to artemether-lumefantrine could provide an efficacious treatment for multidrug-resistant infections., Methods: We conducted an open-label, randomised trial at five hospitals or health centres in three locations (western Cambodia, eastern Cambodia, and Vietnam). Eligible participants were male and female patients aged 2-65 years with uncomplicated Plasmodium falciparum malaria. Patients were randomly allocated (1:1 in blocks of eight to 12) to either artemether-lumefantrine alone (dosed according to WHO guidelines) or artemether-lumefantrine plus amodiaquine (10 mg base per kg/day), both given orally as six doses over 3 days. All received a single dose of primaquine (0·25 mg/kg) 24 h after the start of study treatment to limit transmission of the parasite. Parasites were genotyped, identifying artemisinin resistance. The primary outcome was Kaplan-Meier 42-day PCR-corrected efficacy against recrudescence of the original parasite, assessed by intent-to-treat. Safety was a secondary outcome. This completed trial is registered at ClinicalTrials.gov (NCT03355664)., Findings: Between March 18, 2018, and Jan 30, 2020, 310 patients received randomly allocated treatment; 154 received artemether-lumefantrine alone and 156 received artemether-lumefantrine plus amodiaquine. Parasites from 305 of these patients were genotyped. 42-day PCR-corrected treatment efficacy was noted in 151 (97%, 95% CI 92-99) of 156 patients with artemether-lumefantrine plus amodiaquine versus 146 (95%, 89-97) of 154 patients with artemether-lumefantrine alone; hazard ratio (HR) for recrudescence 0·6 (95% CI 0·2-1·9, p=0·38). Of the 13 recrudescences, 12 were in 174 (57%) of 305 infections with pfkelch13 mutations indicating artemisinin resistance, for which 42-day efficacy was noted in 89 (96%) of 93 infections with artemether-lumefantrine plus amodiaquine versus 73 (90%) of 81 infections with artemether-lumefantrine alone; HR for recrudescence 0·44 (95% CI 0·14-1·40, p=0·17). Artemether-lumefantrine plus amodiaquine was generally well tolerated, but the number of mild (grade 1-2) adverse events, mainly gastrointestinal, was greater in this group compared with artemether-lumefantrine alone (vomiting, 12 [8%] with artemether-lumefantrine plus amodiaquine vs three [2%] with artemether-lumefantrine alone, p=0·03; and nausea, 11 [7%] with artemether-lumefantrine plus amodiaquine vs three [2%] with artemether-lumefantrine alone, p=0·05). Early vomiting within 1 h of treatment, requiring retreatment, occurred in no patients of 154 with artemether-lumefantrine alone versus five (3%) of 156 with artemether-lumefantrine plus amodiaquine, p=0·06. Bradycardia (≤54 beats/min) of any grade was noted in 59 (38%) of 154 patients with artemether-lumefantrine alone and 95 (61%) of 156 with artemether-lumefantrine plus amodiaquine, p=0·0001., Interpretation: Artemether-lumefantrine plus amodiaquine provides an alternative to artemether-lumefantrine alone as first-line treatment for multidrug-resistant P falciparum malaria in the Greater Mekong subregion, and could prolong the therapeutic lifetime of artemether-lumefantrine in malaria-endemic populations., Funding: Bill & Melinda Gates Foundation, Wellcome Trust., Competing Interests: Declaration of interests The Mahidol Oxford Research Unit (MORU) has received funding for other studies of antimalarial treatment from Fosun Pharmaceuticals, which manufactures artemisinin combination therapies. We declare no other competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: Since the introduction of artemisinin-based combination therapy (ACT) in Ghana in 2005 there has been a surveillance system by the National Malaria Control Programme (NMCP) and the University of Ghana Noguchi Memorial Institute for Medical Research (UG-NMIMR) to monitor the therapeutic efficacy of ACTs for the treatment of uncomplicated malaria in the country. We report trends and determinants of failure following treatment of Ghanaian children with artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) combinations., Methods: Per protocol analyses as well as cumulative incidence of day 28 treatment failure from Kaplan Meier survival analyses were used to describe trends of failure over the surveillance period of 2005-2018. Univariable and multivariable cox regression analyses were used to assess the determinants of treatment failure over the period., Results: Day 28 PCR-corrected failure, following treatment with ASAQ, significantly increased from 0.0% in 2005 to 2.0% (95% CI: 1.1-3.6) in 2015 (p = 0.013) but significantly decreased to 0.4% (95% CI: 0.1-1.6) in 2018 (p = 0.039). Failure, following treatment with AL, decreased from 4.5% (95% CI: 2.0-9.4) in 2010 to 2.7% (95% CI: 1.4-5.1) in 2018, though not statistically significant (p = 0.426). Risk of treatment failure, from multivariable cox regression analyses, was significantly lower among children receiving ASAQ compared with those receiving AL (HR = 0.24; 95% CI: 0.11-0.53; p < 0.001); lower among children with no parasitaemia on day 3 compared with those with parasitaemia on day 3 (HR = 0.02; 95% CI: 0.01-0.13; p < 0.001); and higher among children who received ASAQ and had axillary temperature ≥ 37.5 °C on day 1 compared with those with axillary temperature < 37.5 °C (HR = 3.96; 95% CI: 1.61-9.75; p = 0.003)., Conclusions: Treatment failures for both ASAQ and AL have remained less than 5% (below WHO's threshold of 10%) in Ghana since 2005. Predictors of treatment failure that need to be considered in the management of uncomplicated malaria in the country should include type of ACT, day 3 parasitaemia, and day 1 axillary temperature of patients being treated., (© 2021. The Author(s).)

Background: Since 2005, artemisinin-based combination therapy (ACT) has been recommended to treat uncomplicated falciparum malaria in Madagascar. Artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) are the first- and second-line treatments, respectively. A therapeutic efficacy study was conducted to assess ACT efficacy and molecular markers of anti-malarial resistance., Methods: Children aged six months to 14 years with uncomplicated falciparum malaria and a parasitaemia of 1000-100,000 parasites/µl determined by microscopy were enrolled from May-September 2018 in a 28-day in vivo trial using the 2009 World Health Organization protocol for monitoring anti-malarial efficacy. Participants from two communes, Ankazomborona (tropical, northwest) and Matanga (equatorial, southeast), were randomly assigned to ASAQ or AL arms at their respective sites. PCR correction was achieved by genotyping seven neutral microsatellites in paired pre- and post-treatment samples. Genotyping assays for molecular markers of resistance in the pfk13, pfcrt and pfmdr1 genes were conducted., Results: Of 344 patients enrolled, 167/172 (97%) receiving ASAQ and 168/172 (98%) receiving AL completed the study. For ASAQ, the day-28 cumulative PCR-uncorrected efficacy was 100% (95% CI 100-100) and 95% (95% CI 91-100) for Ankazomborona and Matanga, respectively; for AL, it was 99% (95% CI 97-100) in Ankazomborona and 83% (95% CI 76-92) in Matanga. The day-28 cumulative PCR-corrected efficacy for ASAQ was 100% (95% CI 100-100) and 98% (95% CI 95-100) for Ankazomborona and Matanga, respectively; for AL, it was 100% (95% CI 99-100) in Ankazomborona and 95% (95% CI 91-100) in Matanga. Of 83 successfully sequenced samples for pfk13, no mutation associated with artemisinin resistance was observed. A majority of successfully sequenced samples for pfmdr1 carried either the NFD or NYD haplotypes corresponding to codons 86, 184 and 1246. Of 82 successfully sequenced samples for pfcrt, all were wild type at codons 72-76., Conclusion: PCR-corrected analysis indicated that ASAQ and AL have therapeutic efficacies above the 90% WHO acceptable cut-off. No genetic evidence of resistance to artemisinin was observed, which is consistent with the clinical outcome data. However, the most common pfmdr1 haplotypes were NYD and NFD, previously associated with tolerance to lumefantrine., (© 2021. The Author(s).)

Background: Artemisinin-based combination therapy (ACT) has been the recommended first-line treatment for uncomplicated malaria in Mozambique since 2006, with artemether-lumefantrine (AL) and amodiaquine-artesunate (AS-AQ) as the first choice. To assess efficacy of currently used ACT, an in vivo therapeutic efficacy study was conducted., Methods: The study was conducted in four sentinel sites: Montepuez, Moatize, Mopeia and Massinga. Patients between 6 and 59 months old with uncomplicated Plasmodium falciparum malaria (2000-200,000 parasites/µl) were enrolled between February and September of 2018, assigned to either an AL or AS-AQ treatment arm, and monitored for 28 days. A Bayesian algorithm was applied to differentiate recrudescence from new infection using genotyping data of seven neutral microsatellites. Uncorrected and PCR-corrected efficacy results at day 28 were calculated., Results: Totals of 368 and 273 patients were enrolled in the AL and AS-AQ arms, respectively. Of these, 9.5% (35/368) and 5.1% (14/273) were lost to follow-up in the AL and AS-AQ arms, respectively. There were 48 and 3 recurrent malaria infections (late clinical and late parasitological failures) in the AL and AS-AQ arms, respectively. The day 28 uncorrected efficacy was 85.6% (95% confidence interval (CI) 81.3-89.2%) for AL and 98.8% (95% CI 96.7-99.8%) for AS-AQ, whereas day 28 PCR-corrected efficacy was 97.9% (95% CI 95.6-99.2%) for AL and 99.6% (95% CI 97.9-100%) for AS-AQ. Molecular testing confirmed that 87.4% (42/48) and 33.3% (1/3) of participants with a recurrent malaria infection in the AL and AS-AQ arms were new infections; an expected finding in a high malaria transmission area. Adverse events were documented in less than 2% of participants for both drugs., Conclusion: Both AL and AS-AQ have therapeutic efficacies well above the 90% WHO recommended threshold and remain well-tolerated in Mozambique. Routine monitoring of therapeutic efficacy should continue to ensure the treatments remain efficacious. Trial registration Clinicaltrials.gov: NCT04370977., (© 2021. The Author(s).)

Routine assessment of the efficacy of artemisinin-based combination therapies (ACTs) is critical for the early detection of antimalarial resistance. We evaluated the efficacy of ACTs recommended for treatment of uncomplicated malaria in five sites in Democratic Republic of the Congo (DRC): artemether-lumefantrine (AL), artesunate-amodiaquine (ASAQ), and dihydroartemisinin-piperaquine (DP). Children aged 6-59 months with confirmed Plasmodium falciparum malaria were treated with one of the three ACTs and monitored. The primary endpoints were uncorrected and polymerase chain reaction (PCR)-corrected 28-day (AL and ASAQ) or 42-day (DP) cumulative efficacy. Molecular markers of resistance were investigated. Across the sites, uncorrected efficacy estimates ranged from 63% to 88% for AL, 73% to 100% for ASAQ, and 56% to 91% for DP. PCR-corrected efficacy estimates ranged from 86% to 98% for AL, 91% to 100% for ASAQ, and 84% to 100% for DP. No pfk13 mutations previously found to be associated with ACT resistance were observed. Statistically significant associations were found between certain pfmdr1 and pfcrt genotypes and treatment outcome. There is evidence of efficacy below the 90% cutoff recommended by WHO to consider a change in first-line treatment recommendations of two ACTs in one site not far from a monitoring site in Angola that has shown similar reduced efficacy for AL. Confirmation of these findings in future therapeutic efficacy monitoring in DRC is warranted.

The use of Amodiaquine monotherapy is associated with the selection of molecular markers of Plasmodium falciparum resistance to chloroquine (pfcrt and pfmdr1). The decrease in sensitivity and the emergence of P. falciparum resistant to artemisinin-based combination therapy have been reported. Therefore, it is important to assess the impact of treatment of uncomplicated malaria with Artesunate-Amodiaquine (AS+AQ) on molecular markers of antimalarial resistance. We used standard World Health Organization (WHO) protocols to determine the in vivo efficacy of the combination (AS+AQ). In total, 170 subjects were included in the study. The molecular analysis focused on 168 dried blood spots. The aims were to determine the frequency of pfcrt 76T and pfmdr1 86Y mutations and the rates of reinfection using polymorphism markers msp1, msp2, and microsatellite markers (CA1, Ta87, TA99). Nested-PCR was used, followed in some cases by a restriction digestion. The level of P. falciparum clinical response was 92.9% (156/168) of Adequate Clinical and Parasitological Response (ACPR) before molecular correction and 97.0% (163/168) after molecular correction (P = 0.089). The frequency of mutation point pfcrt 76T was 76.2% (128/168) before treatment and 100% (7/7) after treatment (P = 0.1423). For the pfmdr1 mutation, the frequency was 28% (47/168) before treatment and 60% (6/10) after treatment (P = 0.1124). The rate of pfcrt 76T + pfmdr1 86Y was 22% (37/168) before and 50% (6/12) after treatment (P = 0.1465). Despite the presence of AS in the combination, AS+AQ selects for pfcrt 76T and pfmdr1 86Y mutant P. falciparum in Guinea., (© American Society of Parasitologists 2021.)

Background: Artesunate-amodiaquine is a potential therapy for uncomplicated malaria in Cambodia., Methods: Between September 2016 and January 2017, artesunate-amodiaquine efficacy and safety were evaluated in a prospective, open-label, single-arm observational study at health centers in Mondulkiri, Pursat, and Siem Reap Provinces, Cambodia. Adults and children with microscopically confirmed Plasmodium falciparum malaria received oral artesunate-amodiaquine once daily for 3 days plus single-dose primaquine, with follow-up on days 7, 14, 21, and 28. The primary outcome was day-28 polymerase chain reaction (PCR)-adjusted adequate clinical and parasitological response (ACPR). An amodiaquine parasite survival assay (AQSA) was developed and applied to whole genome sequencing results to evaluate potential amodiaquine resistance molecular markers., Results: In 63 patients, day-28 PCR-adjusted ACPR was 81.0% (95% confidence interval [CI], 68.9-88.7). Day 3 parasite positivity rate was 44.4% (28/63; 95% CI, 31.9-57.5). All 63 isolates had the K13(C580Y) marker for artemisinin resistance; 79.4% (50/63) had Pfpm2 amplification. The AQSA resistance phenotype (≥45% parasite survival) was expressed in 36.5% (23/63) of isolates and was significantly associated with treatment failure (P = .0020). Pfmdr1 mutant haplotypes were N86/184F/D1246, and Pfcrt was CVIET or CVIDT at positions 72-76. Additional Pfcrt mutations were not associated with amodiaquine resistance, but the G353V mutant allele was associated with ACPR compared to Pfmdr1 haplotypes harboring F1068L or S784L/R945P mutations (P = .030 and P = .0004, respectively)., Conclusions: For uncomplicated falciparum malaria in Cambodia, artesunate-amodiaquine had inadequate efficacy owing to amodiaquine-resistant P. falciparum. Amodiaquine resistance was not associated with previously identified molecular markers., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: The current first-line treatments for uncomplicated malaria recommended by the National Malaria Control Programme in Mali are artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ). From 2015 to 2016, an in vivo study was carried out to assess the clinical and parasitological responses to AL and ASAQ in Sélingué, Mali., Methods: Children between 6 and 59 months of age with uncomplicated Plasmodium falciparum infection and 2000-200,000 asexual parasites/μL of blood were enrolled, randomly assigned to either AL or ASAQ, and followed up for 42 days. Uncorrected and PCR-corrected efficacy results at days 28 and 42. were calculated. Known markers of resistance in the Pfk13, Pfmdr1, and Pfcrt genes were assessed using Sanger sequencing., Results: A total of 449 patients were enrolled: 225 in the AL group and 224 in the ASAQ group. Uncorrected efficacy at day 28 was 83.4% (95% CI 78.5-88.4%) in the AL arm and 93.1% (95% CI 89.7-96.5%) in the ASAQ arm. The per protocol PCR-corrected efficacy at day 28 was 91.0% (86.0-95.9%) in the AL arm and 97.1% (93.6-100%) in the ASAQ arm. ASAQ was significantly (p < 0.05) better than AL for each of the aforementioned efficacy outcomes. No mutations associated with artemisinin resistance were identified in the Pfk13 gene. Overall, for Pfmdr1, the N86 allele and the NFD haplotype were the most common. The NFD haplotype was significantly more prevalent in the post-treatment than in the pre-treatment isolates in the AL arm (p < 0.01) but not in the ASAQ arm. For Pfcrt, the CVIET haplotype was the most common., Conclusions: The findings indicate that both AL and ASAQ remain effective for the treatment of uncomplicated malaria in Sélingué, Mali.

Introduction: As demonstrated in mathematical models, the simultaneous deployment of multiple first-line therapies (MFT) for uncomplicated malaria, using artemisinin-based combination therapies (ACTs), may extend the useful therapeutic life of the current ACTs. This is possible by reducing drug pressure and slowing the spread of resistance without putting patients' life at risk. We hypothesised that a simultaneous deployment of three different ACTs is feasible, acceptable and can achieve high coverage rate if potential barriers are properly identified and addressed., Methods and Analysis: We plan to conduct a quasi-experimental study in the Kaya health district in Burkina Faso. We will investigate a simultaneous deployment of three ACTs, artemether-lumefantrine, pyronaridine-artesunate, dihydroartesinin-piperaquine, targeting three segments of the population: pregnant women, children under five and individuals aged five years and above. The study will include four overlapping phases: the formative phase, the MFT deployment phase, the monitoring and evaluation phase and the post-evaluation phase. The formative phase will help generate baseline information and develop MFT deployment tools. It will be followed by the MFT deployment phase in the study area. The monitoring and evaluation phase will be conducted as the deployment of MFT progresses. Cross-sectional surveys including desk reviews as well as qualitative and quantitative research methods will be used to assess the study outcomes. Quantitatives study outcomes will be measured using univariate, bivariate and multivariate analysis, including logistic regression and interrupted time series analysis approach. Content analysis will be performed on the qualitative data., Ethics and Dissemination: The Health Research Ethics Committee in Burkina Faso approved the study (Clearance no. 2018-8-113). Study findings will be disseminated through feedback meetings with local communities, national workshops, oral presentations at congresses, seminars and publications in peer-reviewed scientific journals., Trial Registration Number: NCT04265573., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The anti-malarial drug, amodiaquine, a commonly used, long-acting partner drug in artemisinin-based combination therapy, is metabolized to active desethyl-amodiaquine (DEAQ) by cytochrome P450 2C8 (CYP2C8). The CYP2C8 gene carries several polymorphisms including the more frequent minor alleles, CYP2C8*2 and CYP2C8*3. These minor alleles have been associated with decreased enzymatic activity, slowing the amodiaquine biotransformation towards DEAQ. This study aimed to assess the influence of these CYP2C8 polymorphisms on the efficacy and tolerability of artesunate-amodiaquine (AS-AQ) treatment for uncomplicated Plasmodium falciparum malaria in Zanzibar., Methods: Dried blood spots on filter paper were collected from 618 children enrolled in two randomized clinical trials comparing AS-AQ and artemether-lumefantrine in 2002-2005 in Zanzibar. Study participant were under five years of age with uncomplicated falciparum malaria. Human CYP2C8*2 and CYP2C8*3 genotype frequencies were determined by PCR-restriction fragment length polymorphism. Statistical associations between CYP2C8*2 and/or CYP2C8*3 allele carriers and treatment outcome or occurrence of adverse events were assessed by Fisher's exact test., Results: The allele frequencies of CYP2C8*2 and CYP2C8*3 were 17.5 % (95 % CI 15.4-19.7) and 2.7 % (95 % CI 1.8-3.7), respectively. There was no significant difference in the proportion of subjects carrying either CYP2C8*2 or CYP2C8*3 alleles amongst those with re-infections (44.1 %; 95 % CI 33.8-54.8) or those with recrudescent infections (48.3 %; 95 % CI 29.4-67.5), compared to those with an adequate clinical and parasitological response (36.7 %; 95 % CI 30.0-43.9) (P = 0.25 and P = 0.31, respectively). However, patients carrying either CYP2C8*2 or CYP2C8*3 alleles were significantly associated with an increased occurrence of non-serious adverse events, when compared with CYP2C8 *1/*1 wild type homozygotes (44.9 %; 95 % CI 36.1-54.0 vs. 28.1 %; 95 % CI 21.9-35.0, respectively; P = 0.003)., Conclusions: CYP2C8 genotypes did not influence treatment efficacy directly, but the tolerability to AS-AQ may be reduced in subjects carrying the CYP2C8*2 and CYP2C8*3 alleles. The importance of this non-negligible association with regard to amodiaquine-based malaria chemotherapy warrants further investigation.

Objectives: At the end of November 2019, a novel coronavirus responsible for respiratory tract infections (COVID-19) emerged in China. Despite drastic containment measures, this virus, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), spread in Asia and Europe. The pandemic is ongoing with a particular hotspot in Southern Europe and America; many studies predicted a similar epidemic in Africa, as is currently seen in Europe and the United States of America. However, reported data have not confirmed these predictions. One of the hypotheses that could explain the later emergence and spread of COVID-19 pandemic in African countries is the use of antimalarial drugs to treat malaria, and specifically, artemisinin-based combination therapy (ACT)., Methods: The antiviral activity of fixed concentrations of ACT at concentrations consistent with those observed in human plasma when ACT is administered at oral doses for uncomplicated malaria treatment was evaluatedin vitro against a clinically isolated SARS-CoV-2 strain (IHUMI-3) in Vero E6 cells., Results: Mefloquine-artesunate exerted the highest antiviral activity with % inhibition of 72.1 ± 18.3 % at expected maximum blood concentration (C max ) for each ACT drug at doses commonly administered in malaria treatment. All the other combinations, artesunate-amodiaquine, artemether-lumefantrine, artesunate-pyronaridine, or dihydroartemisinin-piperaquine, showed antiviral inhibition in the same ranges (27.1 to 34.1 %)., Conclusions: Antimalarial drugs for which concentration data in the lungs are available are concentrated from 10 to 160 fold more in the lungs than in blood. Thesein vitro results reinforce the hypothesis that antimalarial drugs could be effective as an anti-COVID-19 treatment., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Artemisinin and partner-drug resistance in Plasmodium falciparum are major threats to malaria control and elimination. Triple artemisinin-based combination therapies (TACTs), which combine existing co-formulated ACTs with a second partner drug that is slowly eliminated, might provide effective treatment and delay emergence of antimalarial drug resistance., Methods: In this multicentre, open-label, randomised trial, we recruited patients with uncomplicated P falciparum malaria at 18 hospitals and health clinics in eight countries. Eligible patients were aged 2-65 years, with acute, uncomplicated P falciparum malaria alone or mixed with non-falciparum species, and a temperature of 37·5°C or higher, or a history of fever in the past 24 h. Patients were randomly assigned (1:1) to one of two treatments using block randomisation, depending on their location: in Thailand, Cambodia, Vietnam, and Myanmar patients were assigned to either dihydroartemisinin-piperaquine or dihydroartemisinin-piperaquine plus mefloquine; at three sites in Cambodia they were assigned to either artesunate-mefloquine or dihydroartemisinin-piperaquine plus mefloquine; and in Laos, Myanmar, Bangladesh, India, and the Democratic Republic of the Congo they were assigned to either artemether-lumefantrine or artemether-lumefantrine plus amodiaquine. All drugs were administered orally and doses varied by drug combination and site. Patients were followed-up weekly for 42 days. The primary endpoint was efficacy, defined by 42-day PCR-corrected adequate clinical and parasitological response. Primary analysis was by intention to treat. A detailed assessment of safety and tolerability of the study drugs was done in all patients randomly assigned to treatment. This study is registered at ClinicalTrials.gov, NCT02453308, and is complete., Findings: Between Aug 7, 2015, and Feb 8, 2018, 1100 patients were given either dihydroartemisinin-piperaquine (183 [17%]), dihydroartemisinin-piperaquine plus mefloquine (269 [24%]), artesunate-mefloquine (73 [7%]), artemether-lumefantrine (289 [26%]), or artemether-lumefantrine plus amodiaquine (286 [26%]). The median age was 23 years (IQR 13 to 34) and 854 (78%) of 1100 patients were male. In Cambodia, Thailand, and Vietnam the 42-day PCR-corrected efficacy after dihydroartemisinin-piperaquine plus mefloquine was 98% (149 of 152; 95% CI 94 to 100) and after dihydroartemisinin-piperaquine was 48% (67 of 141; 95% CI 39 to 56; risk difference 51%, 95% CI 42 to 59; p<0·0001). Efficacy of dihydroartemisinin-piperaquine plus mefloquine in the three sites in Myanmar was 91% (42 of 46; 95% CI 79 to 98) versus 100% (42 of 42; 95% CI 92 to 100) after dihydroartemisinin-piperaquine (risk difference 9%, 95% CI 1 to 17; p=0·12). The 42-day PCR corrected efficacy of dihydroartemisinin-piperaquine plus mefloquine (96% [68 of 71; 95% CI 88 to 99]) was non-inferior to that of artesunate-mefloquine (95% [69 of 73; 95% CI 87 to 99]) in three sites in Cambodia (risk difference 1%; 95% CI -6 to 8; p=1·00). The overall 42-day PCR-corrected efficacy of artemether-lumefantrine plus amodiaquine (98% [281 of 286; 95% CI 97 to 99]) was similar to that of artemether-lumefantrine (97% [279 of 289; 95% CI 94 to 98]; risk difference 2%, 95% CI -1 to 4; p=0·30). Both TACTs were well tolerated, although early vomiting (within 1 h) was more frequent after dihydroartemisinin-piperaquine plus mefloquine (30 [3·8%] of 794) than after dihydroartemisinin-piperaquine (eight [1·5%] of 543; p=0·012). Vomiting after artemether-lumefantrine plus amodiaquine (22 [1·3%] of 1703) and artemether-lumefantrine (11 [0·6%] of 1721) was infrequent. Adding amodiaquine to artemether-lumefantrine extended the electrocardiogram corrected QT interval (mean increase at 52 h compared with baseline of 8·8 ms [SD 18·6] vs 0·9 ms [16·1]; p<0·01) but adding mefloquine to dihydroartemisinin-piperaquine did not (mean increase of 22·1 ms [SD 19·2] for dihydroartemisinin-piperaquine vs 20·8 ms [SD 17·8] for dihydroartemisinin-piperaquine plus mefloquine; p=0·50)., Interpretation: Dihydroartemisinin-piperaquine plus mefloquine and artemether-lumefantrine plus amodiaquine TACTs are efficacious, well tolerated, and safe treatments of uncomplicated P falciparum malaria, including in areas with artemisinin and ACT partner-drug resistance., Funding: UK Department for International Development, Wellcome Trust, Bill & Melinda Gates Foundation, UK Medical Research Council, and US National Institutes of Health., (Copyright © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background and Purpose: Resource-limited countries face challenges in setting up effective pharmacovigilance systems. This study aimed to monitor the occurrence of adverse events (AEs) after the use of artemisinin-based combination therapies (ACTs), identify potential drivers of reporting suspected adverse drug reactions (ADRs) and monitor AEs among women who were inadvertently exposed to ACTs in the first trimester of pregnancy., Patients and Methods: We conducted a prospective observational study from May 2010 to July 2012 in Nanoro Health and Demographic Surveillance System (HDSS), Burkina Faso. The HDSS area was divided into active and passive surveillance areas to monitor AEs among patients (regardless of age or sex) who received a first-line ACT (artemether-lumefantrine or artesunate-amodiaquine). In the active surveillance area, patients were followed up for 28 days, while in the passive surveillance area, patients were encouraged to return voluntarily to the health facility to report any occurrence of AEs until day 28 after drug intake. We assessed the crude incidence rates of AEs in both cohorts and performed Cox regression with mixed random effects to identify potential drivers of ADR occurrence., Results: In total, 3170 participants were included in the study. Of these, 40.3% had reported at least one AE, with 39.6% and 44.4% from active and passive surveillance groups, respectively. The types of ADRs were similar in both groups. The most frequent reported ADRs were anorexia, weakness, cough, dizziness and pruritus. One case of abortion and eight cases of death were reported, but none of them was related to the ACT. The variance in random factors showed a high variability of ADR occurrence between patients in both groups, whereas variability between health facilities was low in the active surveillance group and high in passive surveillance group. Taking more than two concomitant medications was associated with high hazard in ADR occurrence, whereas the rainy season was associated with low hazard., Conclusion: This study showed that both passive and active surveillance approaches were useful tools. The HDSS allowed us to capture a few cases of exposure during the first trimester of pregnancy. The passive surveillance approach, which is more likely to be implemented by malaria control programs, seems to be more relevant in the Sub-Saharan African context., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Rouamba et al.)

Background: The majority of Plasmodium falciparum malaria cases in Africa are treated with the artemisinin combination therapies artemether-lumefantrine (AL) and artesunate-amodiaquine (AS-AQ), with amodiaquine being also widely used as part of seasonal malaria chemoprevention programs combined with sulfadoxine-pyrimethamine. While artemisinin derivatives have a short half-life, lumefantrine and amodiaquine may give rise to differing durations of post-treatment prophylaxis, an important additional benefit to patients in higher transmission areas., Methods: We analyzed individual patient data from 8 clinical trials of AL versus AS-AQ in 12 sites in Africa (n = 4214 individuals). The time to PCR-confirmed reinfection after treatment was used to estimate the duration of post-treatment protection, accounting for variation in transmission intensity between settings using hidden semi-Markov models. Accelerated failure-time models were used to identify potential effects of covariates on the time to reinfection. The estimated duration of chemoprophylaxis was then used in a mathematical model of malaria transmission to determine the potential public health impact of each drug when used for first-line treatment., Results: We estimated a mean duration of post-treatment protection of 13.0 days (95% CI 10.7-15.7) for AL and 15.2 days (95% CI 12.8-18.4) for AS-AQ overall. However, the duration varied significantly between trial sites, from 8.7-18.6 days for AL and 10.2-18.7 days for AS-AQ. Significant predictors of time to reinfection in multivariable models were transmission intensity, age, drug, and parasite genotype. Where wild type pfmdr1 and pfcrt parasite genotypes predominated (<=20% 86Y and 76T mutants, respectively), AS-AQ provided ~ 2-fold longer protection than AL. Conversely, at a higher prevalence of 86Y and 76T mutant parasites (> 80%), AL provided up to 1.5-fold longer protection than AS-AQ. Our simulations found that these differences in the duration of protection could alter population-level clinical incidence of malaria by up to 14% in under-5-year-old children when the drugs were used as first-line treatments in areas with high, seasonal transmission., Conclusion: Choosing a first-line treatment which provides optimal post-treatment prophylaxis given the local prevalence of resistance-associated markers could make a significant contribution to reducing malaria morbidity.

Background: Artemisinin-based combination therapy (ACT) is recommended to improve malaria treatment efficacy and limit drug-resistant parasites selection in malaria endemic areas. 5 years after they were adopted, the efficacy and safety of artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ), the first-line treatments for uncomplicated malaria were assessed in Burkina Faso., Methods: In total, 440 children with uncomplicated Plasmodium falciparum malaria were randomized to receive either AL or ASAQ for 3 days and were followed up weekly for 42 days. Blood samples were collected to investigate the ex vivo susceptibility of P. falciparum isolates to lumefantrine, dihydroartemisinin (the active metabolite of artemisinin derivatives) and monodesethylamodiaquine (the active metabolite of amodiaquine). The modified isotopic micro test technique was used to determine the 50% inhibitory concentration (IC50) values. Primary endpoints were the risks of treatment failure at days 42., Results: Out of the 440 patients enrolled, 420 (95.5%) completed the 42 days follow up. The results showed a significantly higher PCR unadjusted cure rate in ASAQ arm (71.0%) than that in the AL arm (49.8%) on day 42, and this trend was similar after correction by PCR, with ASAQ performing better (98.1%) than AL (91.1%). Overall adverse events incidence was low and not significantly different between the two treatment arms. Ex vivo results showed that 6.4% P. falciparum isolates were resistant to monodesthylamodiaquine. The coupled in vivo/ex vivo analysis showed increased IC50 values for lumefantrine and monodesethylamodiaquine at day of recurrent parasitaemia compared to baseline values while for artesunate, IC50 values remained stable at baseline and after treatment failure (p > 0.05)., Conclusion: These findings provide substantial evidence that AL and ASAQ are highly efficacious for the treatment of uncomplicated malaria in children in Burkina Faso. However, the result of P. falciparum susceptibility to the partner drugs advocates the need to regularly replicate such surveillance studies. This would be particularly indicated when amodiaquine is associated in seasonal malaria chemoprophylaxis (SMC) mass drug administration in children under 5 years in Burkina Faso. Trial registration clinicaltrials, NCT00808951. Registered 05 December 2008,https://clinicaltrials.gov/ct2/show/NCT00808951?cond=NCT00808951&rank=1.

Background: A tremendous level of success has been achieved since the introduction of chloroquine and the combination of amodiaquine and artemisinin for the treatment of both complicated and uncomplicated malaria infections in sub-Saharan Africa. However, the recent discovery of drug resistant strains of Plasmodium falciparum (P.f.) and the ability of the parasite to ingest CYP2C8 into its digestive vacuole is of great public health concern. This study probes the occurrence of CYP2C8*2 allelic mutant amongst malaria patients in North-Central Nigeria., Methods: Three hundred and eighty five (385) unrelated study participants were screened for current malaria episodes using routine microscopy and/or rapid diagnostic test strips (RDTs). Chelex extraction method was used for single nucleotide polymorphisms (SNPs) and identification of CYP2C8*2 (805A > T) variant respectively. Wild-type (A) and the defective allele (T) were differentiated with the use of Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). The results obtained were further validated with Sanger sequencing of a few samples and thereafter, the genotype data were statistically processed. All alleles obtained were in Hardy Weinberg equilibrium., Results: Out of the 385 participants (45.5% Male and 54.5% Female) genotyped for SNPs, 75 (19.5%) had the autosomal recessive mutant trait. Occurrence of mutant traits was gender and ethnic independent (p > 0.05). Yoruba ethnic group recorded a reduction in proportion of genotypic defective CYP2C8*2 allele (T) (1 in every 8 persons) with a carrier percentage of 13.3% compared with Hausa (26.62%); Igbo (25.37%) and other minority ethnic groups (17.6%)., Conclusions: A remarkable inter-ethnic differences in autosomal recessive CYP2C8*2 allele was observed. By implication, there is a gradual incursion of genetic drift for poor CQ and AQ-Artemisinin metabolizers among the inhabitants.

The purpose of this study was to update efficacy data of Artesunate-Amodiaquine (AS+AQ) and Artemether-Lumefantrine (AL) used as first-line malaria treatment in Côte d'Ivoire since 2005. This was an open-label, randomized trial conducted in patients older than 6 months with uncomplicated P. falciparum malaria at six sentinel sites. The WHO 2009 protocol on surveillance of anti-malaria drug efficacy was used with primary outcomes as ACPR corrected by PCR at day 42. Secondary endpoints were parasite and fever clearance times and safety. From January to July 2016, 712 patients were included in the trial. 353 and 359 patients were randomly assigned respectively to the AS+AQ and AL arm. Day 42 PCR-adjusted ACPR in the per-protocol analysis was 99.4% and 98.8% in AS+AQ and AL arm respectively. Delayed parasite clearance was observed in six patients at Abidjan and Yamousssoukro sites. Both ACTs were well tolerated. Both ACTs remain efficacious for uncomplicated P. falciparum malaria treatment in Côte d'Ivoire. But regarding delayed parasite clearance observed in this study, a close monitoring and supervision for ACT resistance are essential for future malaria treatment and control strategies in Côte d'Ivoire.

This study aims to evaluate the therapeutic efficacy and tolerance of two ACTs widely used for the treatment of uncomplicated malaria due to Plasmodium falciparum in Niger. The study was conducted from September to November 2017, at the Integrated Health Centers of Dogondoutchi and Birni N'Gaouré, in patients aged from 6 months to 15 years, with uncomplicated malaria due to Plasmodium falciparum. They were treated with either Artemether-Lumefantrine (AL) or Artesunate-Amodiaquine (ASAQ). The primary endpoint was the appropriate clinical and parasitological response (RCPA) to D28, after PCR correction. The secondary criteria were the clearing time of fever, parasites, and gametocytes and then the occurrence of adverse events. A total of 459 patients were examined, of whom 312 patients met the inclusion criteria for therapeutic efficacy evaluation. We have followed 299 patients up to J28 including 146 in the AL arm and 153 in the ASAQ arm. After PCR correction at J28, RCPA were 95.8% and 96% (P = 0.7185) for arms AL and ASAQ, respectively, compared to 93.1% and 94.1% respectively before PCR correction (P = 0.7892). The number of patients on AL and ASAQ treatment who developed an adverse reaction were 6 (7.6%) and 23 (28%) respectively. AL and ASAQ associations are effective and well tolerated. No serious adverse event was noted. However, their monitoring must continue to detect possible resistance., Competing Interests: The authors have no conflicts of interest to declare

During the Ebola virus disease (EVD) epidemic in Western Africa (2013‒2016), antimalarial treatment was administered to EVD patients due to the high coexisting malaria burden in accordance with World Health Organization guidelines. In an Ebola treatment center in Liberia, EVD patients receiving the combination antimalarial artesunate-amodiaquine had a lower risk of death compared to those treated with artemether-lumefantrine. As artemether and artesunate are derivatives of artemisinin, the beneficial anti-Ebola virus (EBOV) effect observed could possibly be attributed to the change from lumefantrine to amodiaquine. Amodiaquine is a widely used antimalarial in the countries that experience outbreaks of EVD and, therefore, holds promise as an approved drug that could be repurposed for treating EBOV infections. We investigated the potential anti-EBOV effect of amodiaquine in a well-characterized nonhuman primate model of EVD. Using a similar 3-day antimalarial dosing strategy as for human patients, plasma concentrations of amodiaquine in healthy animals were similar to those found in humans. However, the treatment regimen did not result in a survival benefit or decrease of disease signs in EBOV-infected animals. While amodiaquine on its own failed to demonstrate efficacy, we cannot exclude potential therapeutic value of amodiaquine when used in combination with artesunate or another antiviral.

Background: Malaria remains a major public health problem, affecting mainly low-and middle-income countries. The management of this parasitic disease is challenged by ever increasing drug resistance. This study, investigated the therapeutic efficacy, tolerability and safety of artemether-lumefantrine (AL) and artesunate-amodiaquine (AS-AQ), used as first-line drugs to treat uncomplicated malaria in Lambaréné, Gabon., Methods: A non-randomized clinical trial was conducted between October 2017 and March 2018 to assess safety, clinical and parasitological efficacy of fixed-doses of AL and AS-AQ administered to treat uncomplicated Plasmodium falciparum malaria in children aged from 6 months to 12 years. After 50 children were treated with AL, another 50 children received ASAQ. The 2009 World Health Organization protocol for monitoring of the efficacy of anti‑malarial drugs was followed. Molecular markers msp1 and msp2 were used to differentiate recrudescence and reinfection. For the investigation of artemisinin resistant markers, gene mutations in Pfk13 were screened., Results: Per-protocol analysis on day 28 showed a PCR corrected cure rate of 97% (95% CI 86-100) and 95% (95% CI 84-99) for AL and AS-AQ, respectively. The most frequent adverse event in both groups was asthenia. No mutations in the kelch-13 gene associated with artemisinin resistance were identified. All participants had completed microscopic parasite clearance by day 3 post-treatment., Conclusion: This study showed that AL and AS-AQ remain efficacious, well-tolerated, and are safe to treat uncomplicated malaria in children from Lambaréné. However, a regular monitoring of efficacy and a study of molecular markers of drug resistance to artemisinin in field isolates is essential. Trial registration ANZCTR, ACTRN12616001600437. Registered 18 November, http://www.anzctr.org.au/TrialSearch.aspx?searchTxt=ACTRN12616001600437p&isBasic=True.

Purpose: Artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) have been widely used for the treatment of uncomplicated Plasmodium falciparum malaria since 2005 in Gabon. Since 2011, a rebound of malaria morbidity has been observed in this country, while no survey evaluating ACT efficacy was performed. During the same period, parasite resistance against artemisinin has been reported in Asia. The aim of this study was to assess the efficacy and tolerability of these two drugs in two sentinel sites of Gabon 10 years after their implementation., Methods: Children aged from 12 to 144 months with uncomplicated malaria were recruited at the Regional Hospital of Melen, Libreville and in the Urban Health Center of Franceville between March 2014 and September 2015. The therapeutic efficacy was evaluated according to the WHO 2008 protocol of 28-day follow-up and PCR-uncorrected/corrected treatment outcomes were assessed., Results: One hundred and eighty-five children (98 ASAQ and 89 AL) were followed up until day 28. The PCR-corrected ACPR was 98.9% for AS-AQ and 96.4% for AL. Late therapeutic failure rate was 3.6% and 1.1% for AL and AS-AQ, respectively (p = 0.2). Adverse events and serious adverse events were rarely observed with both treatments., Conclusion: AS-AQ and AL are still efficacious and well-tolerated for the treatment of uncomplicated malaria in Gabonese children.

Objectives: To investigate the consequence of restricting antimalarial treatment to febrile children that test positive to a malaria rapid diagnostic test (MRDT) only in an area of intense malaria transmission., Methods: Febrile children aged 3-59 months were screened with an MRDT at health facilities in south-west Nigeria. MRDT-positive children received artesunate-amodiaquine (ASAQ), while MRDT-negative children were treated based on the clinical diagnosis of non-malaria febrile illness. The primary endpoint was the risk of developing microscopy-positive malaria within 28 days post-treatment., Results: 309 (60.5%) of 511 children were MRDT-positive while 202 (39.5%) were MRDT-negative at enrolment. 18.5% (50/275) of MRDT-positive children and 7.6% (14/184) of MRDT-negative children developed microscopy-positive malaria by day 28 post-treatment (ρ = 0.001). The risk of developing clinical malaria by day 28 post-treatment was higher among the MRDT-positive group than the MRDT-negative group (adjusted OR 2.74; 95% CI, 1.4, 5.4). A higher proportion of children who were MRDT-positive at enrolment were anaemic on day 28 compared with the MRDT-negative group (12.6% vs. 3.1%; ρ = 0.001). Children in the MRDT-negative group made more unscheduled visits because of febrile illness than those in MRDT-positive group (23.2% vs. 12.0%; ρ = 0.001)., Conclusion: Restricting ACT treatment to MRDT-positive febrile children only did not result in significant adverse outcomes. However, the risk of re-infection within 28 days was significantly higher among MRDT-positive children despite ASAQ treatment. A longer-acting ACT may be needed as the first-line drug of choice for treating uncomplicated malaria in high-transmission settings to prevent frequent re-infections., (© 2019 John Wiley & Sons Ltd.)

Background: The development and spread of artemisinin-resistant Plasmodium falciparum malaria in Greater Mekong Subregion has created impetus for continuing global monitoring of efficacy of artemisinin-based combination therapies (ACTs). This post analyses is aimed to evaluate changes in early treatment response markers 10 years after the adoption of ACTs as first-line treatments of uncomplicated falciparum malaria in Nigeria., Methods: At 14 sentinel sites in six geographical areas of Nigeria, we evaluated treatment responses in 1341 children under 5 years and in additional 360 children under 16 years with uncomplicated malaria enrolled in randomized trials of artemether-lumefantrine versus artesunate-amodiaquine at 5-year interval in 2009-2010 and 2014-2015 and at 2-year interval in 2009-2010 and 2012-2015, respectively after deployment in 2005., Results: Asexual parasite positivity 1 day after treatment initiation (APPD1) rose from 54 to 62% and 2 days after treatment initiation from 5 to 26% in 2009-2010 to 2014-2015 (P = 0.002 and P <  0.0001, respectively). Parasite clearance time increased significantly from 1.6 days (95% confidence interval [CI]: 1.55-1.64) to 1.9 days (95% CI, 1.9-2.0) and geometric mean parasite reduction ratio 2 days after treatment initiation decreased significantly from 11 000 to 4700 within the same time period (P <  0.0001 for each). Enrolment parasitaemia > 75 000 μl - 1 , haematocrit > 27% 1 day post-treatment initiation, treatment with artemether-lumefantrine and enrolment in 2014-2015 independently predicted APPD1. In parallel, Kaplan-Meier estimated risk of recurrent infections by day 28 rose from 8 to 14% (P = 0.005) and from 9 to 15% (P = 0.02) with artemether-lumefantrine and artesunate-amodiaquine, respectively. Mean asexual parasitaemia half-life increased significantly from 1.1 h to 1.3 h within 2 years (P <  0.0001)., Conclusions: These data indicate declining parasitological responses through time to the two ACTs may be due to emergence of parasites with reduced susceptibility or decrease in immunity to the infections in these children., Trial Registration: Pan African Clinical Trial Registration PACTR201508001188143 , 3 July 2015; PACTR201508001191898 , 7 July 2015 and PACTR201508001193368 , 8 July 2015 PACTR201510001189370 , 3 July 2015; PACTR201709002064150 , 1 March 2017; https://www.pactr.samrca.ac.za.

Background: In Equatorial Guinea, malaria continues to be one of the main causes of morbidity and mortality among children. The National Therapeutic Guide established artesunate-amodiaquine (ASAQ) as first-line treatment for uncomplicated malaria, but compliance with this treatment is low. The aim of this study was to assess, for the first time, the performance of public healthcare workers in the diagnosis and treatment of uncomplicated malaria, their compliance with first-line Malaria National Therapeutic Guide and the associated factors., Methods: A cross-sectional survey was conducted at the nine public health facilities in the Bata District of Equatorial Guinea to assess the management of uncomplicated malaria in children < 15 years of age. Bivariate and multivariate statistical analyses were used to determine the recommended treatment compliance and related factors., Results: A total of 227 children with uncomplicated malaria were recorded from 9 public health facilities. Most of the treatments prescribed (83.3%) did not follow the first-line treatment recommended for uncomplicated malaria. The diagnosis was established with parasite confirmation in 182 cases (80.2%). After adjustment for other variables, children under 2 months of age, the use of parasite confirmation to the diagnosis of malaria and being familiar with the national therapeutic guide were significantly associated with the prescription of the first-line recommended treatment. Cases attended at the hospital or in a health facility with ASAQ in the pharmacy at the time of the study were also more likely to be prescribed with the recommended treatment, but with non-significant association after adjustment for other variables., Conclusions: This study identified the factors associated with the low compliance with the first-line treatment by the public healthcare facilities of Bata District of Equatorial Guinea. It seems necessary to improve case management of children with uncomplicated malaria; to reinforce the use of Malaria National Therapeutic Guide and to inform about the danger of using artemisinin monotherapy. Furthermore, it is crucial to provide recommended first-line treatment to the pharmacies of all public health facilities to ensure access to this treatment., Competing Interests: The authors have declared that no competing interests exist.

Background: Routine surveillance on the therapeutic efficacy of artemisinin-based combination therapy (ACT) has been ongoing in Ghana since 2005. The sixth round of surveillance was conducted between 2015 and 2017 to determine the therapeutic efficacy of artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) in 10 sentinel sites across the country., Methods: The study was a one-arm, prospective, evaluation of the clinical, parasitological, and haematological responses to directly observed treatment with AS-AQ and AL among children 6 months to 9 years old with uncomplicated falciparum malaria. The WHO 2009 protocol on surveillance of anti-malaria drug efficacy was used for the study with primary outcomes as prevalence of day 3 parasitaemia and clinical and parasitological cure rates on day 28. Secondary outcomes assessed included patterns of fever and parasite clearance as well as changes in haemoglobin concentration., Results: Day 3 parasitaemia was absent in all sites following treatment with AS-AQ whilst only one person (0.2%) was parasitaemic on day 3 following treatment with AL. Day 28 PCR-corrected cure rates following treatment with AS-AQ ranged between 96.7% (95% CI 88.5-99.6) and 100%, yielding a national rate of 99.2% (95% CI 97.7-99.7). Day 28 PCR-corrected cure rates following treatment with AL ranged between 91.3% (95% CI 79.2-97.6) and 100%, yielding a national rate of 96% (95% CI 93.5-97.6). Prevalence of fever declined by 88.4 and 80.4% after first day of treatment with AS-AQ and AL, respectively, whilst prevalence of parasitaemia on day 2 was 2.1% for AS-AQ and 1.5% for AL. Gametocytaemia was maintained at low levels (< 5%) during the 3 days of treatment. Post-treatment mean haemoglobin concentration was significantly higher than pre-treatment concentration following treatment with either AS-AQ or AL., Conclusions: The therapeutic efficacy of AS-AQ and AL is over 90% in sentinel sites across Ghana. The two anti-malarial drugs therefore remain efficacious in the treatment of uncomplicated malaria in the country and continue to achieve rapid fever and parasite clearance as well as low gametocyte carriage rates and improved post-treatment mean haemoglobin concentration.

Background and Objective: Prior small-scale clinical trials showed that Artemisia annua and Artemisia afra infusions, decoctions, capsules, or tablets were low cost, easy to use, and efficient in curing malaria infections. In a larger-scale trial in Kalima district, Democratic Republic of Congo, we aimed to show A. annua and/or A. afra infusions were superior or at least equivalent to artesunate-amodiaquine (ASAQ) against malaria., Methods: A double blind, randomized clinical trial with 957 malaria-infected patients had two treatment arms: 472 patients for ASAQ and 471 for Artemisia (248 A. annua, 223 A. afra) remained at end of the trial. ASAQ-treated patients were treated per manufacturer posology, and Artemisia-treated patients received 1 l/d of dry leaf/twig infusions for 7 d; both arms had 28 d follow-up. Parasitemia and gametocytes were measured microscopically with results statistically compared among arms for age and gender., Results: Artemisinin content of A. afra was negligible, but therapeutic responses of patients were similar to A. annua-treated patients; trophozoites cleared after 24  h, but took up to 14 d to clear in ASAQ-treated patients. D28 cure rates defined as absence of parasitemia were for pediatrics 82, 91, and 50% for A. afra, A. annua and ASAQ; while for adults cure rates were 91, 100, and 30%, respectively. Fever clearance took 48  h for ASAQ, but 24  h for Artemisia. From D14-28 no Artemisia-treated patients had microscopically detectable gametocytes, while 10 ASAQ-treated patients remained gametocyte carriers at D28. More females than males were gametocyte carriers in the ASAQ arm but were unaffected in the Artemisia arms. Hemoglobin remained constant at 11 g/dl for A. afra after D1, while for A. annua and ASAQ it decreased to 9-9.5  g/dl. Only 5.0% of Artemisia-treated patients reported adverse effects, vs. 42.8% for ASAQ., Conclusion: A. annua and A. afra infusions are polytherapies with better outcomes than ASAQ against malaria. In contrast to ASAQ, both Artemisias appeared to break the cycle of malaria by eliminating gametocytes. This study merits further investigation for possible inclusion of Artemisia tea infusions as an alternative for fighting and eradicating malaria., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Background: The Tanzanian National Malaria Control Programme (NMCP) and its partners have been implementing regular therapeutic efficacy studies (TES) to monitor the performance of different drugs used or with potential use in Tanzania. However, most of the recent TES focused on artemether-lumefantrine, which is the first-line anti-malarial for the treatment of uncomplicated falciparum malaria. Data on the performance of other artemisinin-based combinations is urgently needed to support timely review and changes of treatment guidelines in case of drug resistance to the current regimen. This study was conducted at two NMCP sentinel sites (Kibaha, Pwani and Ujiji, Kigoma) to assess the efficacy and safety of artesunate-amodiaquine (ASAQ) and dihydroartemisinin-piperaquine (DP), which are the current alternative artemisinin-based combinations in Tanzania., Methods: This was a single-arm prospective evaluation of the clinical and parasitological responses of ASAQ and DP for directly observed treatment of uncomplicated falciparum malaria. Children aged 6 months to 10 years and meeting the inclusion criteria were enrolled and treated with either ASAQ or DP. In each site, patients were enrolled sequentially; thus, enrolment of patients for the assessment of one artemisinin-based combination was completed before patients were recruited for assessment of the second drugs. Follow-up was done for 28 or 42 days for ASAQ and DP, respectively. The primary outcome was PCR corrected cure rates while the secondary outcome was occurrence of adverse events (AEs) or serious adverse events (SAEs)., Results: Of the 724 patients screened at both sites, 333 (46.0%) were enrolled and 326 (97.9%) either completed the 28/42 days of follow-up, or attained any of the treatment outcomes. PCR uncorrected adequate clinical and parasitological response (ACPR) for DP on day 42 was 98.8% and 75.9% at Kibaha and Ujiji, respectively. After PCR correction, DP's ACPR was 100% at both sites. For ASAQ, no parasite recurrence occurred giving 100% ACPR on day 28. Only one patient in the DP arm (1.1%) from Ujiji had parasites on day 3. Of the patients recruited (n = 333), 175 (52.6%) had AEs with 223 episodes (at both sites) in the two treatment groups. There was no SAE and the commonly reported AE episodes (with > 5%) included, cough, running nose, abdominal pain, diarrhoea and fever., Conclusion: Both artemisinin-based combinations had high cure rates with PCR corrected ACPR of 100%. The two drugs had adequate safety with no SAE and all AEs were mild, and not associated with the anti-malarials. Continued TES is critical to monitor the performance of nationally recommended artemisinin-based combination therapy and supporting evidence-based review of malaria treatment policies. Trial registration This study is registered at ClinicalTrials.gov, No. NCT03431714.

Introduction: Artemisinin-based combination therapies (ACTs) are the first-line antimalarial drugs used to treat uncomplicated Plasmodium falciparum alaria in many endemic countries worldwide. The present work reviewed the therapeutic efficacy of ACT in Cameroon more than 10 years after the initial change in national drug policy in 2004., Methods: A PubMed literature search was performed to analyse clinical trials conducted in Cameroon from 2001 to May 2017. Clinical studies that evaluated ACT for the treatment of uncomplicated falciparum malaria in children or adults, and reported efficacy and/or safety, were included. In addition, a small network meta-analysis (NMA) with a frequentist approach was performed., Results: Six papers were selected from 48 articles screened and were full-text reviewed. The efficacy of both artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ) ranged from moderate to high, with polymerase chain reaction-corrected cure rates ranging from 96.7 to 100% and 88.2 to 100%, respectively, in per-protocol analysis, and 86.2 to 96.7% and 74.0 to 90.6%, respectively, in intention-to-treat analysis. The malaria evidence network suggested that AL and ASAQ efficacies were comparable. The highest day 3 parasite positivity rate was 8.2% for ASAQ and 4% for AL. A novel ACT, artesunate-atovaquoneproguanil (ASATPG) was tested once and showed a cure rate of 100%. Based on an ITT approach, the NMA revealed that AL was more efficacious than ASAQ, but the difference was not statistical significant (706 participants, three randomised clinical trials (RCT); OR 1.25, 95%CI 0.78-2.00). Adverse events ranged from mild to moderate severity but were not directly attributed to drug intake., Conclusion: ACTs are still effective and safe in Cameroon; however, there are insufficient data on their efficacy, safety and tolerability, therefore more RCTs should be conducted, including novel ACTs.

Background: The World Health Organization recommends the use of artemisinin-based combination therapy (ACT) to treat uncomplicated malaria for the control of malaria across the world. There are several types of ACT used across malaria-endemic countries, yet there is little information about preferences and adherence practices regarding different types of ACT. The objective of this study was to evaluate levels of adherence to two types of ACT, artemether-lumefantrine (AL) and artesunate + amodiaquine (ASAQ), for the treatment of uncomplicated malaria among prescribers and patients in Guinea in 2016., Methods: The study included a review of records of malaria patients and three health-facility, cross-sectional surveys. Patients diagnosed with uncomplicated malaria and prescribed ACT (n = 1830) were recruited and visited in their home after receiving the medication and administered a questionnaire regarding ACT adherence. Prescribers (n = 115) and drug dispensers (n = 43) were recruited at the same public health facilities and administered questionnaires regarding prescribing practices and opinions regarding the national treatment policies and protocols., Results: According to the registry review, 35.8% of all-cause consultations were recorded as malaria. Of these, 26.6% were diagnosed clinically without documentation of laboratory confirmation. The diagnosis of uncomplicated malaria represented 64.1% of malaria cases among children under 5 years and 74.9% of those 5 years of age and older. An ACT was prescribed for 83.5% of cases of uncomplicated malaria. Among participants in the study, ACT adherence was 95.4% (95% CI 94.4, 96.3). Overall, about one in four patients (23.4%; 95% CI 21.5, 25.3) reported experiencing adverse events. While patients prescribed ASAQ were significantly more likely to report experiencing adverse effects than patients on AL (p < 0.001), given the overall high adherence, there was no evidence of a statistically significant difference in adherence between AL and ASAQ. Patients 5 years or older who reported experiencing adverse events were more likely to be non-adherent., Conclusion: Although there were more reported adverse events associated with ASAQ when compared with AL, both prescribers and patients were found to be mostly adherent to ACT for the treatment of malaria, regardless of ACT type.

Background: Artemisinin-based combination therapy (ACT) is the first-line anti-malarial treatment of uncomplicated malaria in most malaria endemic countries, including Tanzania. Unfortunately, there have been reports of artemisinin resistance and ACT failure from South East Asia highlighting the need to monitor therapeutic efficacy of ACT in these countries as recommended by World Health Organization., Methods: Open-label single arm studies in mainland Tanzania were conducted in nine sentinel sites in 2011, 2012 and 2015 to assess the efficacy and safety of artemether/lumefantrine (AL) and artesunate/amodiaquine (ASAQ) using 28 days follow-up and dihydroartemisinin/piperaquine (DHAPQ) using 42 days follow-up. Mutations in the propeller domain of the Plasmodium falciparum kelch 13 (k13) gene and amplification of the P. falciparum plasmepsin 2 (pm2) gene, associated with artemisinin and piperaquine (PQ) resistance, were also investigated., Results: Of the 428 patients enrolled, 328 patients provided study endpoint. For AL, the PCR corrected per-protocol analysis showed adequate clinical and parasitological response (ACPR) of 90.3% (n = 28; 95% CI 74.2-98.0) in Kyela 2012, 95.7% (n = 22; 95% CI 78.1-99.0) in Chamwino, 100% in Muheza (n = 29; 95% CI 88.1-100), 100% in Nagaga (n = 39; 95% CI 91.0-100) and Kyela 2015 (n = 60; 95% CI 94.0-100). For ASAQ, PCR corrected ACPR of 98% (n = 49; 95% CI 89.4-99.9) and 100% (n = 25; 95% CI 86.3-100) were observed in 2011 in Ujiji and Kibaha, respectively. For DHAPQ, the ACPR was 100% (n = 71; 95% CI 94.9-100). Of the 235 samples with genetic interpretable results, only 7 (3%) had non-synonymous k13 mutations. None of these are candidate or validated markers of artemisinin resistance and all patients carrying these alleles cleared the parasites on day 3. Of the DHAPQ group, 10% (3/29) of the samples with interpretable results had pm2 multiple copies and none of them was associated with treatment failure., Conclusion: All the tested ACT in mainland Tanzania were highly efficacious and none of validated k13 mutants associated with artemisinin resistance was observed. However, three isolates with multiple copy numbers of pm2 gene associated with PQ resistance among the limited samples tested successfully calls for further investigation. Trial registration Number ACTRN12615000159550. Registered 18th February 2015, https://www.anzctr.org.au/trial/MyTrial.aspx.

The efficacies of 3-day regimens of artemether-lumefantrine (AL), artesunate-amodiaquine (AA), and dihydroartemisinin-piperaquine (DHP) were evaluated in 910 children < 5 years old with uncomplicated malaria from six geographical areas of Nigeria. Parasite positivity 1 day and Kaplan-Meier estimated risk of persistent parasitemia 3 days after therapy initiation were both significantly higher, and geometric mean parasite reduction ratio 1 day after treatment initiation (PRRD1) was significantly lower in AL-treated children than in AA- and DHP-treated children. No history of fever, temperature > 38°C, enrollment parasitemia > 75,000 μL -1 , and PRRD1 < 5,000 independently predicted persistent parasitemia 1 day after treatment initiation. Parasite clearance was significantly faster and risk of reappearance of asexual parasitemia after initial clearance was significantly lower in DHP-treated children. Overall, day 42 polymerase chain reaction-corrected efficacy was 98.3% (95% confidence interval [CI]: 96.1-100) and was similar for all treatments. In a non-compartment model, declines of parasitemias were monoexponential with mean terminal elimination half-life of 1.3 hours and unimodal frequency distribution of half-lives. All treatments were well tolerated. In summary, all three treatments evaluated remain efficacious treatments of uncomplicated malaria in young Nigerian children, but DHP appears more efficacious than AL or AA.

Background: Since 2006, the artemisinin-based combination therapy (ACT) are recommended to treat uncomplicated malaria including non Plasmodium falciparum malaria in Madagascar. Artesunate-amodiaquine (ASAQ) and artemether-lumefantrine are the first- and second-line treatment in uncomplicated falciparum malaria, respectively. No clinical drug efficacy study has been published since 2009 to assess the efficacy of these two artemisinin-based combinations in Madagascar, although the incidence of malaria cases has increased from 2010 to 2016. In this context, new data about the efficacy of the drug combinations currently used to treat malaria are needed., Methods: Therapeutic efficacy studies evaluating the efficacy of ASAQ were conducted in 2012, 2013 and 2016 among falciparum malaria-infected patients aged between 6 months and 56 years, in health centres in 6 sites representing different epidemiological patterns. The 2009 World Health Organization protocol for monitoring anti-malarial drug efficacy was followed., Results: A total of 348 enrolled patients met the inclusion criteria including 108 patients in 2012 (n = 64 for Matanga, n = 44 for Ampasipotsy), 123 patients in 2013 (n = 63 for Ankazomborona, n = 60 for Anjoma Ramartina) and 117 patients in 2016 (n = 67 for Tsaratanana, n = 50 for Antanimbary). The overall cumulative PCR-corrected day 28 cure rate was 99.70% (95% IC 98.30-99.95). No significant difference in cure rates was observed overtime: 99.02% (95% IC 94.65-99.83) in 2012; 100% (95% IC 96.8-100) in 2013 and 100% (95% IC 96.65-100) in 2016., Conclusion: The ASAQ combination remains highly effective for the treatment of uncomplicated falciparum malaria in Madagascar.