51
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Sowunmi A, Akano K, Ntadom G, Ayede AI, Ibironke FO, Aderoyeje T, Adewoye EO, Fatunmbi B, Oguche S, Okafor HU, Watila I, Meremikwu M, Agomo P, Ogala W, Agomo C, Folarin OA, Gbotosho GO, Happi CT. Therapeutic efficacy and effects of artemisinin-based combination treatments on uncomplicated Plasmodium falciparum malaria -associated anaemia in Nigerian children during seven years of adoption as first-line treatments. Infect Dis Poverty 2017; 6:36. [PMID: 28173853 PMCID: PMC5294876 DOI: 10.1186/s40249-016-0217-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 12/14/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Artemisinin-based combination treatments (ACTs) are the first-line treatments of uncomplicated Plasmodium falciparum malaria in many endemic areas but there are few evaluation of their efficacy in anaemic malarious children. METHODS Therapeutic efficacy of 3-day regimens of artesunate-amodiaquine and artemether-lumefantrine was evaluated in 437 anaemic and 909 non-anaemic malarious children following treatment during a seven-year period (2008-2014). Patterns of temporal changes in haematocrit were classified based on haematocrit values <30% and ≥30%. Kinetics of the disposition of the deficit in haematocrit from 30% following treatment were evaluated using a non-compartment model. RESULTS PCR-corrected parasitological efficacy 28 days after start of treatment was significantly higher in artesunate-amodiaquine- compared to artemether-lumefantrine-treated children [97% (95%CI: 92.8-100) versus 96.4% (95%CI: 91.3-99.4), P = 0.02], but it was similar in non-anaemic and anaemic children. Fall in haematocrit/1 000 asexual parasites cleared from peripheral blood was significantly greater at lower compared to higher parasitaemias (P < 0.0001), and in non-anaemic compared to anaemic children (P = 0.007). In anaemic children at presentation, mean anaemia recovery time (AnRT) was 15.4 days (95%CI: 13.3-17.4) and it did not change over the years. Declines in haematocrit deficits from 30% were monoexponential with mean estimated half-time of 1.4 days (95%CI: 1.2-1.6). Anaemia half-time (t½anaemia) correlated positively with AnRT in the same patients (r = 0.69, P < 0.0001). Bland-Altman analysis of 10 multiples of t½anaemia and AnRT showed narrow limit of agreement with insignificant bias (P = 0.07) suggesting both can be used interchangeably in the same patients. CONCLUSIONS Artesunate-amodiaquine and artemether-lumefantrine remain efficacious treatments of uncomplicated P. falciparum infections in non-anaemic and anaemic Nigerian children in the last 7 years of adoption as first-line treatments. These ACTs may also conserve haematocrit at high parasitaemias and in anaemic children. TRIALS REGISTRATION Pan African Clinical Trial Registry PACTR201508001188143 , 3 July 2015; PACTR201510001189370 , 3 July 2015; PACTR201508001191898 , 7 July 2015 and PACTR201508001193368 , 8 July 2015.
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Affiliation(s)
- Akintunde Sowunmi
- Department of Pharmacology and Therapeutics, University of Ibadan, Ibadan, Nigeria
- Institute for Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria
- Department of Clinical Pharmacology, University College Hospital, Ibadan, Nigeria
| | - Kazeem Akano
- Department of Pharmacology and Therapeutics, University of Ibadan, Ibadan, Nigeria
| | - Godwin Ntadom
- National Malaria Elimination Programme, Federal Ministry of Health, Abuja, Nigeria
| | | | - Folasade O. Ibironke
- Department of Clinical Pharmacology, University College Hospital, Ibadan, Nigeria
| | - Temitope Aderoyeje
- Department of Clinical Pharmacology, University College Hospital, Ibadan, Nigeria
| | | | - Bayo Fatunmbi
- World Health Organization, Regional Office for the Western Pacific, Khan Daun Penh, Phnom Penh Cambodia
| | - Stephen Oguche
- Department of Paediatrics, University of Jos, Jos, Nigeria
| | - Henrietta U. Okafor
- Department of Paediatrics, Institute of Child Health, University of Nigeria Teaching Hospital, Enugu, Nigeria
| | - Ismaila Watila
- Department of Paediatrics, Specialist Hospital, Maiduguri, Borno Sate Nigeria
| | - Martin Meremikwu
- Department of Paediatrics, University of Calabar, Calabar, Cross Rivers State Nigeria
| | - Philip Agomo
- Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria
| | - William Ogala
- Department of Paediatrics, Ahmadu Bello University, Zaria, Nigeria
| | - Chimere Agomo
- Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Onikepe A. Folarin
- Department of Biological Sciences, Redeemer’s University, Ede, Osun State Nigeria
| | - Grace O. Gbotosho
- Department of Pharmacology and Therapeutics, University of Ibadan, Ibadan, Nigeria
- Institute for Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Christian T. Happi
- Department of Biological Sciences, Redeemer’s University, Ede, Osun State Nigeria
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Muhamad P, Thiengsusuk A, Phompradit P, Na-Bangchang K. In vitro sensitivity of antimalarial drugs and correlation with clinico-parasitological response following treatment with a 3-day artesunate-mefloquine combination in patients with falciparum malaria along the Thai-Myanmar border. Acta Trop 2017; 166:257-261. [PMID: 27866919 DOI: 10.1016/j.actatropica.2016.11.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 10/10/2016] [Accepted: 11/16/2016] [Indexed: 11/25/2022]
Abstract
A 3-day artesunate-mefloquine combination therapy has been using as first-line treatment for acute uncomplicated Plasmodium falciparum malaria in Thailand since 1995 on the background of mefloquine resistance. The aim of the present study was to assess sensitivity of P. falciparum isolates (n=44) in an area along the Thai-Myanmar border (year 2009) to artesunate, mefloquine, chloroquine and quinine, including their correlation with clinico-parasitological response. Twenty, 19, and 5 isolates were collected from patients with 'Adequate Clinical and Parasitological Response (ACPR)', 'Late Parasitological Failure (LPF)' and 're-infection', respectively. The IC50 of artesunate and mefloquine were significantly higher in patients with LPF compared with ACPR and re-infection. The proportion of isolates with declined artesunate or mefloquine sensitivity in the LPF group (47.4%) was significantly higher than the ACPR group (5.0%). A weak but statistical significant correlation (r=0.384, p=0.01) was observed between IC50 values of artesunate and parasite clearance time (PCT). There was no significant relationship between in vitro sensitivity of parasite isolates to chloroquine or quinine and clinical response. In vitro susceptibility of P. falciparum isolates to artesunate and mefloquine may be used as a useful reliable tool to predict clinico-pathological response following a 3-day artesunate-mefloquine combination therapy.
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Abstract
Bioinformatic analysis can not only accelerate drug target identification and drug candidate screening and refinement, but also facilitate characterization of side effects and predict drug resistance. High-throughput data such as genomic, epigenetic, genome architecture, cistromic, transcriptomic, proteomic, and ribosome profiling data have all made significant contribution to mechanismbased drug discovery and drug repurposing. Accumulation of protein and RNA structures, as well as development of homology modeling and protein structure simulation, coupled with large structure databases of small molecules and metabolites, paved the way for more realistic protein-ligand docking experiments and more informative virtual screening. I present the conceptual framework that drives the collection of these high-throughput data, summarize the utility and potential of mining these data in drug discovery, outline a few inherent limitations in data and software mining these data, point out news ways to refine analysis of these diverse types of data, and highlight commonly used software and databases relevant to drug discovery.
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Affiliation(s)
- Xuhua Xia
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
- Ottawa Institute of Systems Biology, Ottawa K1H 8M5, Canada
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54
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4-Aminoquinoline-ferrocenyl-chalcone conjugates: Synthesis and anti-plasmodial evaluation. Eur J Med Chem 2017; 125:269-277. [DOI: 10.1016/j.ejmech.2016.09.044] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 02/02/2023]
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The Effects of Transdermally Delivered Oleanolic Acid on Malaria Parasites and Blood Glucose Homeostasis in P. berghei-Infected Male Sprague-Dawley Rats. PLoS One 2016; 11:e0167132. [PMID: 27907019 PMCID: PMC5132303 DOI: 10.1371/journal.pone.0167132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 11/09/2016] [Indexed: 11/19/2022] Open
Abstract
The present study investigated the effects of transdermally delivered oleanolic acid (OA) monotherapy and in combination with chloroquine (CHQ) on malaria parasites and glucose homeostasis of P. berghei-infected male Sprague-Dawley rats. Oral glucose test (OGT) responses to OA-pectin patch and CHQ-OA combination matrix patch were monitored in non-infected and infected rats. To evaluate the short-term effects of treatment, percentage parasitaemia, blood glucose, glycogen and plasma insulin were monitored in separate groups of animals treated with either OA-patch monotherapy or CHQ-OA combination pectin patch over a 21-days period. Animals treated with drug-free pectin and CHQ acted as untreated and treated positive controls, respectively. Infected control rats exhibited significantly increased parasitaemia which was accompanied by hypoglycaemia. Both OA monotherapy and CHQ-OA combination therapy reduced and cleared the malaria parasites within a period of 4 and 3 days, respectively. Compared to respective controls groups, OGT responses of animals treated with OA monotherapy or CHQ-OA combination therapy exhibited lower blood glucose levels at all time points. A once-off transdermal application of OA-patch or CHQ-OA combination patch significantly improved blood glucose concentrations inducing any changes in insulin concentration. Transdermal OA used as a monotherapy or in combination with CHQ is able to clear and reduce the malaria parasites within a shorter period of time without eliciting any adverse effects on glucose homeostasis of P. berghei-infected rats.
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Godse CS, Tathed PS, Talwalkar SS, Vaidya RA, Amonkar AJ, Vaidya AB, Vaidya ADB. Antiparasitic and disease-modifying activity of Nyctanthes arbor-tristis Linn. in malaria: An exploratory clinical study. J Ayurveda Integr Med 2016; 7:238-248. [PMID: 27914754 PMCID: PMC5192257 DOI: 10.1016/j.jaim.2016.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 08/04/2016] [Accepted: 08/06/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND An unceasing threat of drug resistance continuously poses demand for new antimalarial drugs. A scientific assessment of traditionally used antimalarial plants through reverse pharmacology is crucial for a fast track drug discovery. An Ayurvedic plant Nyctanthes arbor-tristis Linn. - (Parijat) is being used in clinical practice and had shown antimalarial activity, with a parasite clearance in 76.6% of 120 patients, in an earlier clinical study. OBJECTIVE To further explore antimalarial potential of the plant through additional objective markers. MATERIALS AND METHODS An open-labelled observational study was conducted at M.A. Podar Hospital - Ayurveda (MAPH-A) after ethics committee approval. Administration of a paste of 5 fresh leaves, thrice a day for a week was a standard practice for management of malaria at MAPH-A. Clinical activity of N. arbor-tristis was evaluated by monitoring pyrexia, parasitemia and morbidity score (MS) in twenty patients. In addition, immune and biochemical markers and organ functions were monitored for objective markers of response. Student's paired-'t' test was applied to assess statistical significance. RESULTS Ten out of 20 patients showed both fever and parasite clearance, which was confirmed by polymerase chain reaction. Remaining ten patients had persistent but decreasing parasitemia. Four of them needed chloroquine as a fail-safe procedure. Irrespective of the degree of parasitemia all the patients showed decrease in MS. There was also an increase in platelet count and normalization of plasma lactic acid. There was a good clinical tolerability and an improvement in organ function. The inflammatory cytokines showed a reduction; particularly in TNF-α within a day. CONCLUSIONS At the given dosage, N. arbor-tristis showed disease-modifying activity; early clinical recovery with a decline of TNF-α and a gradual parasite clearance. Further studies with a standardised formulation for dose-searching and optimizing the treatment schedule are needed in a larger sample size. CLINICAL TRIAL REGISTRATION NO The process of trial registration had not begun when the study was conducted in 2000.
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Affiliation(s)
- Chhaya S Godse
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India.
| | - Prakash S Tathed
- Yerala Medical Trust's Ayurvedic Medical College and Hospital (YMTA), Sector 4, Kharghar, Navi Mumbai 410210, India
| | - Sameer S Talwalkar
- CPA Lab, Hematopathology and Molecular Diagnostics Division, Louisville, KY 40220, USA
| | - Rama A Vaidya
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
| | - Ashok J Amonkar
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
| | - Akhil B Vaidya
- Centre for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA; ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
| | - Ashok D B Vaidya
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
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Woodrow CJ, White NJ. The clinical impact of artemisinin resistance in Southeast Asia and the potential for future spread. FEMS Microbiol Rev 2016; 41:34-48. [PMID: 27613271 PMCID: PMC5424521 DOI: 10.1093/femsre/fuw037] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/11/2016] [Accepted: 07/31/2016] [Indexed: 11/25/2022] Open
Abstract
Artemisinins are the most rapidly acting of currently available antimalarial drugs. Artesunate has become the treatment of choice for severe malaria, and artemisinin-based combination therapies (ACTs) are the foundation of modern falciparum malaria treatment globally. Their safety and tolerability profile is excellent. Unfortunately, Plasmodium falciparum infections with mutations in the ‘K13’ gene, with reduced ring-stage susceptibility to artemisinins, and slow parasite clearance in patients treated with ACTs, are now widespread in Southeast Asia. We review clinical efficacy data from the region (2000–2015) that provides strong evidence that the loss of first-line ACTs in western Cambodia, first artesunate-mefloquine and then DHA-piperaquine, can be attributed primarily to K13 mutated parasites. The ring-stage activity of artemisinins is therefore critical for the sustained efficacy of ACTs; once it is lost, rapid selection of partner drug resistance and ACT failure are inevitable consequences. Consensus methods for monitoring artemisinin resistance are now available. Despite increased investment in regional control activities, ACTs are failing across an expanding area of the Greater Mekong subregion. Although multiple K13 mutations have arisen independently, successful multidrug-resistant parasite genotypes are taking over and threaten to spread to India and Africa. Stronger containment efforts and new approaches to sustaining long-term efficacy of antimalarial regimens are needed to prevent a global malaria emergency. Artemisinin resistance in Plasmodium falciparum malaria is causing failure of artemisinin-based combination therapies across an expanding area of Southeast Asia, undermining control and elimination efforts. The potential global consequences can only be avoided by new approaches that ensure sustained efficacy for antimalarial regimens in malaria affected populations.
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Affiliation(s)
- Charles J Woodrow
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6, Rajvithi Road, Bangkok 10400, Thailand
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6, Rajvithi Road, Bangkok 10400, Thailand
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58
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Sowunmi A, Akano K, Ayede AI, Ntadom G, Adewoye EO, Fatunmbi B, Aderoyeje T. Therapeutic efficacy and effects of artesunate-amodiaquine and artemether-lumefantrine on malaria-associated anaemia in Nigerian children aged two years and under. Infect Dis Poverty 2016; 5:70. [PMID: 27384596 PMCID: PMC4933999 DOI: 10.1186/s40249-016-0165-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/28/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Artemisinin-based combination therapies are recommended as first-line treatments for uncomplicated falciparum malaria, but there is little evaluation of their efficacy and effects on uncomplicated malaria-associated anaemia in children aged 2 years and under. METHODS Parasitological efficacy and effects on malaria-associated anaemia were evaluated in 250 malarious children aged 2 years and under, and efficacy was evaluated in 603 malarious children older than two but younger than 5 years of age following treatment with artesunate-amodiaquine (AA) or artemether-lumefantrine (AL). Kinetics of the disposition of parasitaemia following treatment were evaluated using a non-compartment model. Late-appearing anaemia (LAA) was diagnosed using the following criteria: clearance of parasitaemia, fever and other symptoms occurring within 7 days of starting treatment, adequate clinical and parasitological response on days 28-42, haematocrit (HCT) ≥ 30 % at 1 and/or 2 weeks, a fall in HCT to < 30 % occurring at 3-6 weeks, absence of concomitant illness at 1-6 weeks, and absence of asexual parasitaemia detected using both microscopy and polymerase chain reaction (PCR) at 1-6 weeks. RESULTS Overall, in children aged 2 years and under, the PCR-corrected parasitological efficacy was 97.2 % (95 % CI 92.8-101.6), which was similar for both treatments. In children older than 2 years, parasitological efficacy was also similar for both treatments, but parasite prevalence 1 day after treatment began was significantly higher, and fever and parasite clearance times were significantly faster in the AA-treated children compared with the AL-treated children. Declines in parasitaemia were monoexponential with an estimated elimination half-time of 1 h. Elimination half-times were similar for both treatments. In children aged 2 years and under who were anaemic at presentation, the mean anaemia recovery time was 12.1 days (95 % CI 10.6-13.6, n = 127), which was similar for both treatments. Relatively asymptomatic LAA occurred in 11 children (4.4 %) aged 2 years and under, the recovery from which was uneventful. CONCLUSION This study showed that AA and AL are efficacious treatments for uncomplicated falciparum malaria in Nigerian children aged 2 years and under, and that AA clears parasitaemia and fever significantly faster than AL in children older than 2 years. Both treatments may cause a relatively asymptomatic LAA with uneventful recovery in a small proportion of children aged 2 years and under. TRIALS REGISTRATION Pan African Clinical Trial Registry PACTR201508001188143, 3 July 2015; PACTR201510001189370, 3 July 2015; PACTR201508001191898, 7 July 2015 and PACTR201508001193368, 8 July 2015 http://www.pactr.org .
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Affiliation(s)
- Akintunde Sowunmi
- />Department of Pharmacology and Therapeutics, University of Ibadan, Ibadan, Nigeria
- />Institute for Medical Research and Training, University of Ibadan, Ibadan, Nigeria
| | - Kazeem Akano
- />Department of Pharmacology and Therapeutics, University of Ibadan, Ibadan, Nigeria
| | | | - Godwin Ntadom
- />Malaria Elimination Programme, Federal Ministry of Health, Abuja, Nigeria
| | - Elsie O. Adewoye
- />Department of Physiology, University of Ibadan, Ibadan, Nigeria
| | - Bayo Fatunmbi
- />World Health Organization, Regional Office for the Western Pacific, Phnom Penh, Cambodia
| | - Temitope Aderoyeje
- />Department of Clinical Pharmacology, University College Hospital, Ibadan, Nigeria
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Phyo AP, Ashley EA, Anderson TJC, Bozdech Z, Carrara VI, Sriprawat K, Nair S, White MM, Dziekan J, Ling C, Proux S, Konghahong K, Jeeyapant A, Woodrow CJ, Imwong M, McGready R, Lwin KM, Day NPJ, White NJ, Nosten F. Declining Efficacy of Artemisinin Combination Therapy Against P. Falciparum Malaria on the Thai-Myanmar Border (2003-2013): The Role of Parasite Genetic Factors. Clin Infect Dis 2016; 63:784-791. [PMID: 27313266 PMCID: PMC4996140 DOI: 10.1093/cid/ciw388] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/05/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Deployment of mefloquine-artesunate (MAS3) on the Thailand-Myanmar border has led to a sustained reduction in falciparum malaria, although antimalarial efficacy has declined substantially in recent years. The role of Plasmodium falciparum K13 mutations (a marker of artemisinin resistance) in reducing treatment efficacy remains controversial. METHODS Between 2003 and 2013, we studied the efficacy of MAS3 in 1005 patients with uncomplicated P. falciparum malaria in relation to molecular markers of resistance. RESULTS Polymerase chain reaction (PCR)-adjusted cure rates declined from 100% in 2003 to 81.1% in 2013 as the proportions of isolates with multiple Pfmdr1 copies doubled from 32.4% to 64.7% and those with K13 mutations increased from 6.7% to 83.4%. K13 mutations conferring moderate artemisinin resistance (notably E252Q) predominated initially but were later overtaken by propeller mutations associated with slower parasite clearance (notably C580Y). Those infected with both multiple Pfmdr1 copy number and a K13 propeller mutation were 14 times more likely to fail treatment. The PCR-adjusted cure rate was 57.8% (95% confidence interval [CI], 45.4, 68.3) compared with 97.8% (95% CI, 93.3, 99.3) in patients with K13 wild type and Pfmdr1 single copy. K13 propeller mutation alone was a strong risk factor for recrudescence (P = .009). The combined population attributable fraction of recrudescence associated with K13 mutation and Pfmdr1 amplification was 82%. CONCLUSIONS The increasing prevalence of K13 mutations was the decisive factor for the recent and rapid decline in efficacy of artemisinin-based combination (MAS3) on the Thailand-Myanmar border.
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Affiliation(s)
- Aung Pyae Phyo
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Elizabeth A Ashley
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Tim J C Anderson
- Department of Genetics, Texas Biomedical Research Institute, San Antonio; and
| | - Zbynek Bozdech
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Verena I Carrara
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Shalini Nair
- Department of Genetics, Texas Biomedical Research Institute, San Antonio; and
| | - Marina McDew White
- Department of Genetics, Texas Biomedical Research Institute, San Antonio; and
| | - Jerzy Dziekan
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Clare Ling
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Stephane Proux
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Kamonchanok Konghahong
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Atthanee Jeeyapant
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Charles J Woodrow
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rose McGready
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Khin Maung Lwin
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Francois Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
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Lobo L, Sousa BD, Cabral L, Cristiano ML, Nogueira F. Highly active ozonides selected against drug resistant malaria. Mem Inst Oswaldo Cruz 2016; 0:0. [PMID: 27276364 PMCID: PMC4957497 DOI: 10.1590/0074-02760160077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/13/2016] [Indexed: 11/21/2022] Open
Abstract
Ever increasing multi-drug resistance by Plasmodium falciparum is creating new challenges in malaria chemotherapy. In the absence of licensed vaccines, treatment and prevention of malaria is heavily dependent on drugs. Potency, range of activity, safety, low cost and ease of administration are crucial issues in the design and formulation of antimalarials. We have tested three synthetic ozonides NAC89, LC50 and LCD67 in vitro and in vivo against multidrug resistant Plasmodium. In vitro, LC50 was at least 10 times more efficient inhibiting P. falciparum multidrug resistant Dd2 strain than chloroquine and mefloquine and as efficient as artemisinin (ART), artesunate and dihydroartemisinin. All three ozonides showed high efficacy in clearing parasitaemia in mice, caused by multi-drug resistant Plasmodium chabaudi strains, by subcutaneous administration, demonstrating high efficacy in vivo against ART and artesunate resistant parasites.
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Affiliation(s)
- Lis Lobo
- Universidade Nova de Lisboa, Universidade Nova de Lisboa, Lisboa , Portugal, Universidade Nova de Lisboa, Unidade de Ensino e Investigação de Parasitologia Médica, Global Health and Tropical Medicine, Lisboa, Portugal
| | - Bruno de Sousa
- Universidade de Coimbra, Universidade de Coimbra, Faculdade de Psicologia e Ciências de Educação, Coimbra , Portugal, Universidade de Coimbra, Faculdade de Psicologia e Ciências de Educação, Coimbra, Portugal
| | - Lília Cabral
- Universidade do Algarve, Universidade do Algarve, Centro de Ciências do Mar e Departamento de Química e Farmácia, Faro , Portugal, Universidade do Algarve, Centro de Ciências do Mar e Departamento de Química e Farmácia, Faro, Portugal
| | - Maria Ls Cristiano
- Universidade do Algarve, Universidade do Algarve, Centro de Ciências do Mar e Departamento de Química e Farmácia, Faro , Portugal, Universidade do Algarve, Centro de Ciências do Mar e Departamento de Química e Farmácia, Faro, Portugal
| | - Fátima Nogueira
- Universidade Nova de Lisboa, Universidade Nova de Lisboa, Lisboa , Portugal, Universidade Nova de Lisboa, Unidade de Ensino e Investigação de Parasitologia Médica, Global Health and Tropical Medicine, Lisboa, Portugal
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Ley B, Alam MS, Thriemer K, Hossain MS, Kibria MG, Auburn S, Poirot E, Price RN, Khan WA. G6PD Deficiency and Antimalarial Efficacy for Uncomplicated Malaria in Bangladesh: A Prospective Observational Study. PLoS One 2016; 11:e0154015. [PMID: 27128675 PMCID: PMC4851315 DOI: 10.1371/journal.pone.0154015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/07/2016] [Indexed: 12/19/2022] Open
Abstract
Background The Bangladeshi national treatment guidelines for uncomplicated malaria follow WHO recommendations but without G6PD testing prior to primaquine administration. A prospective observational study was conducted to assess the efficacy of the current antimalarial policy. Methods Patients with uncomplicated malaria, confirmed by microscopy, attending a health care facility in the Chittagong Hill Tracts, Bangladesh, were treated with artemether-lumefantrine (days 0–2) plus single dose primaquine (0.75mg/kg on day2) for P. falciparum infections, or with chloroquine (days 0–2) plus 14 days primaquine (3.5mg/kg total over 14 days) for P. vivax infections. Hb was measured on days 0, 2 and 9 in all patients and also on days 16 and 30 in patients with P. vivax infection. Participants were followed for 30 days. The study was registered with the clinical trials website (NCT02389374). Results Between September 2014 and February 2015 a total of 181 patients were enrolled (64% P. falciparum, 30% P. vivax and 6% mixed infections). Median parasite clearance times were 22.0 (Interquartile Range, IQR: 15.2–27.3) hours for P. falciparum, 20.0 (IQR: 9.5–22.7) hours for P. vivax and 16.6 (IQR: 10.0–46.0) hours for mixed infections. All participants were afebrile within 48 hours, two patients with P. falciparum infection remained parasitemic at 48 hours. No patient had recurrent parasitaemia within 30 days. Adjusted male median G6PD activity was 7.82U/gHb. One male participant (1/174) had severe G6PD deficiency (<10% activity), five participants (5/174) had mild G6PD deficiency (10–60% activity). The Hb nadir occurred on day 2 prior to primaquine treatment in P. falciparum and P. vivax infected patients; mean fractional fall in Hb was -8.8% (95%CI -6.7% to -11.0%) and -7.4% (95%CI: -4.5 to -10.4%) respectively. Conclusion The current antimalarial policy remains effective. The prevalence of G6PD deficiency was low. Main contribution to haemolysis in G6PD normal individuals was attributable to acute malaria rather than primaquine administration. Trial Registration ClinicalTrials.gov NCT02389374
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Affiliation(s)
- Benedikt Ley
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | | | - Kamala Thriemer
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | | | | | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Eugenie Poirot
- Global Health Group, University of California San Francisco, San Francisco, California, United States of America
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Wasif Ali Khan
- International Centre for Diarrheal Diseases and Research, Dhaka, Bangladesh
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Tun KM, Jeeyapant A, Imwong M, Thein M, Aung SSM, Hlaing TM, Yuentrakul P, Promnarate C, Dhorda M, Woodrow CJ, Dondorp AM, Ashley EA, Smithuis FM, White NJ, Day NPJ. Parasite clearance rates in Upper Myanmar indicate a distinctive artemisinin resistance phenotype: a therapeutic efficacy study. Malar J 2016; 15:185. [PMID: 27036739 PMCID: PMC4815199 DOI: 10.1186/s12936-016-1240-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/16/2016] [Indexed: 01/23/2023] Open
Abstract
Background Artemisinin resistance in Plasmodium falciparum extends across Southeast Asia where it is associated with worsening partner drug resistance and a decline in the efficacy of frontline artemisinin-based combination therapy. Dihydroartemisinin-piperaquine (DP) is an essential component of preventive and curative treatment in the region, but its therapeutic efficacy has fallen in Cambodia. Methods A prospective clinical and parasitological evaluation of DP was conducted at two sites in Upper Myanmar between August 2013 and December 2014, enrolling 116 patients with acute uncomplicated falciparum malaria. Patients received DP orally for 3 days together with primaquine 0.25 mg/kg on admission. Parasite clearance half-lives based on 6 hourly blood smears, and day 42 therapeutic responses were assessed as well as parasite K13 genotypes. Results Median parasite clearance half-life was prolonged, and clearance half-life was greater than 5 h in 21 % of patients. Delayed parasite clearance was significantly associated with mutations in the propeller region of the parasite k13 gene. The k13 F446I mutation was found in 25.4 % of infections and was associated with a median clearance half-life of 4.7 h compared with 2.7 h for infections without k13 mutations (p < 0.001). There were no failures after 42 days of follow-up, although 18 % of patients had persistent parasitaemia on day 3. Conclusion The dominant k13 mutation observed in Upper Myanmar, F446I, appears to be associated with an intermediate rate of parasite clearance compared to other common mutations described elsewhere in the Greater Mekong Subregion. Discerning this phenotype requires relatively detailed clearance measurements, highlighting the importance of methodology in assessing artemisinin resistance. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1240-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kyaw Myo Tun
- Defence Services Medical Research Centre, Naypyitaw, Myanmar.,Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
| | - Atthanee Jeeyapant
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Min Thein
- Defence Services Medical Research Centre, Naypyitaw, Myanmar
| | | | | | - Prayoon Yuentrakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand
| | | | - Mehul Dhorda
- Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.,Worldwide Antimalarial Resistance Network (WWARN), Bangkok, Thailand
| | - Charles J Woodrow
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Elizabeth A Ashley
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand
| | - Frank M Smithuis
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.,Medical Action Myanmar, Yangon, Myanmar
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Ratchawithi Rd., Ratchathewi District, Bangkok, 10400, Thailand. .,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.
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Yang B, Ma LP, Ma W, Wei SJ, Ji HY, Li HG, Dang HW, Liu C, Wu XL, Chen J. A self-contrast approach to evaluate the inhibitory effect of chrysosplenetin, in the absence and presence of artemisinin, on the in vivo P-glycoprotein-mediated digoxin transport activity. Biomed Chromatogr 2016; 30:1582-90. [PMID: 27012321 DOI: 10.1002/bmc.3725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 01/22/2016] [Accepted: 03/18/2016] [Indexed: 11/12/2022]
Abstract
In this study, we used a self-contrast method, which excluded the individual difference, to evaluate the inhibitory effect of chrysosplentin (CHR) in the presence or absence of artemisinin (ART) on the P-glycoprotein (P-gp) transport activity. A sensitive and rapid UHPLC-MS/MS method was applied for quantification of digoxin, a P-gp-specific substrate, in rat plasma. A pharmacokinetic study was carried out: first after an oral administration of digoxin at a dose of 0.09 mg/kg (first period), followed by a 20-day wash-out, then after another administration of digoxin (second period). During the second period, test compounds were orally given three times per day for seven consecutive days. Results showed that the t1/2 of digoxin in all the groups had no significant difference between the first and second periods. The AUC0-24 , Cmax , tmax , and Clz /F of the negative control and ART alone groups showed no difference. However, the AUC0-24 and Cmax in the CHR alone, CHR-ART (1:2) and verapamil (positive control) groups showed 2.34-, 3.04-, 1.79-, and 1.81-, 1.99-, 2.06-fold increases along with 3.50-, 3.84- and 4.76-fold decreases for CLz /F, respectively. The tmax in the CHR-ART (1:2) group increased 3.73-fold. In conclusion, our self-contrast study suggested that CHR, especially when combined with ART in a ratio of 1:2, inhibited P-gp activity while ART alone has no effect. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Bei Yang
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Li-Ping Ma
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Wei Ma
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Shi-Jie Wei
- Institute of Clinical Pharmaco, General Hospital of Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Hong-Yan Ji
- Institute of Clinical Pharmaco, General Hospital of Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Hou-Gang Li
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Hong-Wan Dang
- Institute of Clinical Pharmaco, General Hospital of Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Cheng Liu
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Xiu-Li Wu
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, People's Republic of China
| | - Jing Chen
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, People's Republic of China
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Ramani S, Parija SC, Mandal J, Hamide A, Bhat V. Detection of chloroquine and artemisinin resistance molecular markers in Plasmodium falciparum: A hospital based study. Trop Parasitol 2016; 6:69-77. [PMID: 26998436 PMCID: PMC4778185 DOI: 10.4103/2229-5070.175110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Introduction: Emergence of chloroquine (CQ) resistance in Plasmodium falciparum has increased the morbidity and mortality of falciparum malaria worldwide. Artemisinin-based combination therapies are now recommended by the World Health Organization as the first line treatment for falciparum malaria. Numerous molecular markers have been implicated in the CQ and artemisinin resistance. Materials and Methods: A total of 26 confirmed cases of falciparum malaria (by giemsa stained thick and thin smear, quantitative buffy coat, immunochromatographic test, or polymerase chain reaction [PCR]) were included in the study. About 5 ml of ethylenediaminetetraacetic acid blood sample was collected and stored at −20°C till use. Plasmodium DNA was extracted using QIAamp whole blood DNA extraction kit. PCR was done to amplify pfcrt, pfmdr1, pfserca, and pfmrp1 genes and the amplicons obtained were sequenced by Macrogen, Inc., Korea. Single nucleotide polymorphism (SNP) analysis was done using Bio-Edit Sequence Alignment Editor. Results: Out of the four genes targeted, we noted a SNP in the pfcrt gene alone. This SNP (G > T) was noted in the 658th position of the gene, which was seen in 13 patients. The pfmdr1 and pfserca genes were present in 9 and 14 patients respectively. But we could not find any SNPs in these genes. This SNP in pfcrt gene was not significantly associated with any adverse outcome and neither altered disease progression. Conclusion: Presence of a single SNP may not be associated with any adverse clinical outcome. As the sample size was small, we may have not been able to detect any other known or unknown polymorphisms.
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Affiliation(s)
- S Ramani
- Department of Microbiology, Jawaharlal Nehru Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Subhash Chandra Parija
- Department of Microbiology, Jawaharlal Nehru Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Jharna Mandal
- Department of Microbiology, Jawaharlal Nehru Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Abdoul Hamide
- Department of Medicine, Jawaharlal Nehru Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Vishnu Bhat
- Department of Paediatrics, Jawaharlal Nehru Institute of Postgraduate Medical Education and Research, Puducherry, India
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65
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Should we abandon quinine plus antibiotic for treating uncomplicated falciparum malaria? A systematic review and meta-analysis of randomized controlled trials. Parasitol Res 2015; 115:903-12. [DOI: 10.1007/s00436-015-4842-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
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Teneza-Mora N, Lumsden J, Villasante E. A malaria vaccine for travelers and military personnel: Requirements and top candidates. Vaccine 2015; 33:7551-8. [DOI: 10.1016/j.vaccine.2015.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 09/23/2015] [Accepted: 10/02/2015] [Indexed: 10/22/2022]
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Abdulla S, Ashley EA, Bassat Q, Bethell D, Björkman A, Borrmann S, D'Alessandro U, Dahal P, Day NP, Diakite M, Djimde AA, Dondorp AM, Duong S, Edstein MD, Fairhurst RM, Faiz MA, Falade C, Flegg JA, Fogg C, Gonzalez R, Greenwood B, Guérin PJ, Guthmann JP, Hamed K, Hien TT, Htut Y, Juma E, Lim P, Mårtensson A, Mayxay M, Mokuolu OA, Moreira C, Newton P, Noedl H, Nosten F, Ogutu BR, Onyamboko MA, Owusu-Agyei S, Phyo AP, Premji Z, Price RN, Pukrittayakamee S, Ramharter M, Sagara I, Se Y, Suon S, Stepniewska K, Ward SA, White NJ, Winstanley PA. Baseline data of parasite clearance in patients with falciparum malaria treated with an artemisinin derivative: an individual patient data meta-analysis. Malar J 2015; 14:359. [PMID: 26390866 PMCID: PMC4578675 DOI: 10.1186/s12936-015-0874-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/26/2015] [Indexed: 11/15/2022] Open
Abstract
Background Artemisinin resistance in Plasmodium falciparum manifests as slow parasite clearance but this measure is also influenced by host immunity, initial parasite biomass and partner drug efficacy. This study collated data from clinical trials of artemisinin derivatives in falciparum malaria with frequent
parasite counts to provide reference parasite clearance estimates stratified by location, treatment and time, to examine host factors affecting parasite clearance, and to assess the relationships between parasite clearance and risk of recrudescence during follow-up. Methods Data from 24 studies, conducted from 1996 to 2013, with frequent parasite counts were pooled. Parasite clearance half-life (PC1/2) was estimated using the WWARN Parasite Clearance Estimator. Random effects regression models accounting for study and site heterogeneity were used to explore factors affecting PC1/2 and risk of recrudescence within areas with reported delayed parasite clearance (western Cambodia, western Thailand after 2000, southern Vietnam, southern Myanmar) and in all other areas where parasite populations are artemisinin sensitive. Results PC1/2 was estimated in 6975 patients, 3288 of whom also had treatment outcomes evaluate d during 28–63 days follow-up, with 93 (2.8 %) PCR-confirmed recrudescences. In areas with artemisinin-sensitive parasites, the median PC1/2 following three-day artesunate treatment (4 mg/kg/day) ranged from 1.8 to 3.0 h and the proportion of patients with PC1/2 >5 h from 0 to 10 %. Artesunate doses of 4 mg/kg/day decreased PC1/2 by 8.1 % (95 % CI 3.2–12.6) compared to 2 mg/kg/day, except in populations with delayed parasite clearance. PC1/2 was longer in children and in patients with fever or anaemia at enrolment. Long PC1/2 (HR = 2.91, 95 % CI 1.95–4.34 for twofold increase, p < 0.001) and high initial parasitaemia (HR = 2.23, 95 % CI 1.44–3.45 for tenfold increase, p < 0.001) were associated independently with an increased risk of recrudescence. In western Cambodia, the region with the highest prevalence of artemisinin resistance, there was no evidence for increasing PC1/2 since 2007. Conclusions Several factors affect PC1/2. As substantial heterogeneity in parasite clearance exists between locations, early detection of artemisinin resistance requires reference PC1/2 data. Studies with frequent parasite count measurements to characterize PC1/2 should be encouraged. In western Cambodia, where PC1/2 values are longest, there is no evidence for recent emergence of higher levels of artemisinin resistance. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0874-1) contains supplementary material, which is available to authorized users.
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Wang Y, Yang Z, Yuan L, Zhou G, Parker D, Lee MC, Yan G, Fan Q, Xiao Y, Cao Y, Cui L. Clinical Efficacy of Dihydroartemisinin-Piperaquine for the Treatment of Uncomplicated Plasmodium falciparum Malaria at the China-Myanmar Border. Am J Trop Med Hyg 2015; 93:577-83. [PMID: 26283743 DOI: 10.4269/ajtmh.15-0029] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/28/2015] [Indexed: 11/07/2022] Open
Abstract
Artemisinin-based combination therapies (ACTs) are currently used as the first-line therapy for uncomplicated Plasmodium falciparum malaria. However, the recent emergence and/or spread of artemisinin resistance in parts of Greater Mekong Subregion (GMS) of southeast Asia requires close monitoring of the therapeutic efficacy of ACTs. This study was conducted from March 2012 to December 2013 in four clinics and seven villages along the China-Myanmar border. A total of 109 patients with uncomplicated falciparum malaria were treated with dihydroartemisinin-piperaquine (DP) and followed up on days 1, 2, 3, 7, 14, 21, 28, and 42 after treatment. A total of 71 patients (22 children and 49 adults) completed the 42-day follow-up. DP remained highly efficacious for treatment of uncomplicated falciparum malaria with an overall 42-day cure rate of 100%. The day 3 parasite-positive rate was 7.04% (5/71). Within 14 days of treatment, a total of 13 (18.31%) patients had detectable gametocytes and a large proportion of these were persistent from the first three days of treatment. The presence of gametocytes in patients through 14 days after DP treatment suggests that the incorporation of a single dose of primaquine for clearing gametocytemia should be considered for blocking parasite transmission.
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Affiliation(s)
- Ying Wang
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Zhaoqing Yang
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Lili Yuan
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Guofa Zhou
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Daniel Parker
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Ming-Chieh Lee
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Guiyun Yan
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Qi Fan
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Yuping Xiao
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Yaming Cao
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
| | - Liwang Cui
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China; Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China; Program in Public Health, University of California at Irvine, Irvine, California; Dalian Institute of Biotechnology, Dalian, Liaoning, China; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China; Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
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Getnet G, Fola AA, Alemu A, Getie S, Fuehrer HP, Noedl H. Therapeutic efficacy of artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum malaria in Enfranze, north-west Ethiopia. Malar J 2015; 14:258. [PMID: 26105035 PMCID: PMC4477607 DOI: 10.1186/s12936-015-0775-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 06/13/2015] [Indexed: 11/10/2022] Open
Abstract
Background Plasmodium falciparum accounts for approximately 60% of malaria cases in Ethiopia and artemether–lumefantrine has been used as a first-line treatment for uncomplicated P. falciparum malaria since 2004. The aim of this study was to assess the therapeutic efficacy of artemether–lumefantrine (AL) for the treatment of uncomplicated P. falciparum malaria in north-western Ethiopia. Methods A 28-day one-arm, prospective evaluation of the clinical and parasitological response to the first-line treatment for uncomplicated P. falciparum malaria was conducted in Enfranze Health Centre in accordance with the 2009 WHO efficacy study guidelines. Patients were treated with a 3-day course of AL and clinical and parasitological parameters were monitored over a 28-day follow-up. All data from recruited patients were imported into an electronic data base and Kaplan–Meier survival analysis was used for analysing primary [early treatment failures (ETF), late clinical failure (LCF), late parasitological failures (LPF), and adequate clinical and parasitological response (ACPR)] and secondary (PCT, GCT and FCT) outcomes. Results Eighty patients were enrolled and all of them completed the 28-day follow-up period. The PCR-corrected cure rate was 95.0% (95% CI 87.0–98.4%) and there were two ETF, one LCF and three LPF. Two of the LPF were classified as re infections by PCR. Seventy three point seven five percent, 91.25 and 95% of patients had cleared their parasitaemia by days 1, 2, and 3, respectively, and 75, 91.25 and 96.25% of patients had cleared their fever by days 1, 2, and 3. All patients completely cleared their gametocytes by day 7. Conclusion The relatively high cure rate, low proportion of patients still positive on day 3 as well as parasite clearance times in this study would indicate no imminent threat of artemisinin resistance development in the region. However, the threat of spreading or de novo development of artemisinin resistance warrants regular monitoring of drug efficacy throughout the region.
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Affiliation(s)
- Gebeyaw Getnet
- Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
| | - Abebe Alemu Fola
- School of Medicine, College of Health Sciences and Medicine, Wolaita Sodo University, Wolaita, Ethiopia. .,The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.
| | - Agersew Alemu
- Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
| | - Sisay Getie
- Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
| | - Hans-Peter Fuehrer
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria.
| | - Harald Noedl
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria.
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Shannon KL, Ahmed S, Rahman H, Prue CS, Khyang J, Ram M, Haq MZ, Chowdhury A, Akter J, Glass GE, Shields T, Nyunt MM, Khan WA, Sack DA, Sullivan DJ. Hemoglobin E and Glucose-6-Phosphate Dehydrogenase Deficiency and Plasmodium falciparum Malaria in the Chittagong Hill Districts of Bangladesh. Am J Trop Med Hyg 2015; 93:281-6. [PMID: 26101273 DOI: 10.4269/ajtmh.14-0623] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 04/16/2015] [Indexed: 11/07/2022] Open
Abstract
Hemoglobin E is largely confined to south and southeast Asia. The association between hemoglobin E (HbE) and malaria is less clear than that of hemoglobin S and C. As part of a malaria study in the Chittagong Hill Districts of Bangladesh, an initial random sample of 202 individuals showed that 39% and 49% of Marma and Khyang ethnic groups, respectively, were positive for either heterozygous or homozygous hemoglobin E. In this group, 6.4% were also found to be severely deficient and 35% mildly deficient for glucose-6-phosphate dehydrogenase (G6PD). In a separate Plasmodium falciparum malaria case-uninfected control study, the odds of having homozygous hemoglobin E (HbEE) compared with normal hemoglobin (HbAA) were higher among malaria cases detected by passive surveillance than age and location matched uninfected controls (odds ratio [OR] = 5.0, 95% confidence interval [CI] = 1.07-46.93). The odds of heterozygous hemoglobin E (HbAE) compared with HbAA were similar between malaria cases and uninfected controls (OR = 0.71, 95% CI = 0.42-1.19). No association by hemoglobin type was found in the initial parasite density or the proportion parasite negative after 2 days of artemether/lumefantrine treatment. HbEE, but not HbAE status was associated with increased passive case detection of malaria.
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Affiliation(s)
- Kerry L Shannon
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Sabeena Ahmed
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Hafizur Rahman
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Chai S Prue
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Jacob Khyang
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Malathi Ram
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - M Zahirul Haq
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Ashish Chowdhury
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Jasmin Akter
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Gregory E Glass
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Timothy Shields
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Myaing M Nyunt
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Wasif A Khan
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - David A Sack
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - David J Sullivan
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Centre for Population, Urbanization and Climate Change, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Djimde AA, Makanga M, Kuhen K, Hamed K. The emerging threat of artemisinin resistance in malaria: focus on artemether-lumefantrine. Expert Rev Anti Infect Ther 2015; 13:1031-45. [PMID: 26081265 DOI: 10.1586/14787210.2015.1052793] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The development of artemisinin resistance in the Greater Mekong Subregion poses a significant threat to malaria elimination. Artemisinin-based combination therapies including artemether-lumefantrine (AL) are recommended by WHO as first-line treatment for uncomplicated Plasmodium falciparum malaria. This article provides a comprehensive review of the existing and latest data as a basis for interpretation of observed variability in parasite sensitivity to AL over the last 5 years. Clinical efficacy and preclinical data from a range of endemic countries are summarized, including potential molecular markers of resistance. Overall, AL remains effective in the treatment of uncomplicated P. falciparum malaria in most regions. Establishing validated molecular markers for resistance and strict efficacy monitoring will reinforce timely updates of treatment policies.
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Affiliation(s)
- Abdoulaye A Djimde
- Malaria Research and Training Center, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
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Ex Vivo Drug Susceptibility Testing and Molecular Profiling of Clinical Plasmodium falciparum Isolates from Cambodia from 2008 to 2013 Suggest Emerging Piperaquine Resistance. Antimicrob Agents Chemother 2015; 59:4631-43. [PMID: 26014942 DOI: 10.1128/aac.00366-15] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/18/2015] [Indexed: 12/26/2022] Open
Abstract
Cambodia's first-line artemisinin combination therapy, dihydroartemisinin-piperaquine (DHA-PPQ), is no longer sufficiently curative against multidrug-resistant Plasmodium falciparum malaria at some Thai-Cambodian border regions. We report recent (2008 to 2013) drug resistance trends in 753 isolates from northern, western, and southern Cambodia by surveying for ex vivo drug susceptibility and molecular drug resistance markers to guide the selection of an effective alternative to DHA-PPQ. Over the last 3 study years, PPQ susceptibility declined dramatically (geomean 50% inhibitory concentration [IC50] increased from 12.8 to 29.6 nM), while mefloquine (MQ) sensitivity doubled (67.1 to 26 nM) in northern Cambodia. These changes in drug susceptibility were significantly associated with a decreased prevalence of P. falciparum multidrug resistance 1 gene (Pfmdr1) multiple copy isolates and coincided with the timing of replacing artesunate-mefloquine (AS-MQ) with DHA-PPQ as the first-line therapy. Widespread chloroquine resistance was suggested by all isolates being of the P. falciparum chloroquine resistance transporter gene CVIET haplotype. Nearly all isolates collected from the most recent years had P. falciparum kelch13 mutations, indicative of artemisinin resistance. Ex vivo bioassay measurements of antimalarial activity in plasma indicated 20% of patients recently took antimalarials, and their plasma had activity (median of 49.8 nM DHA equivalents) suggestive of substantial in vivo drug pressure. Overall, our findings suggest DHA-PPQ failures are associated with emerging PPQ resistance in a background of artemisinin resistance. The observed connection between drug policy changes and significant reduction in PPQ susceptibility with mitigation of MQ resistance supports reintroduction of AS-MQ, in conjunction with monitoring of the P. falciparum mdr1 copy number, as a stop-gap measure in areas of DHA-PPQ failure.
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Implications of Glutathione Levels in the Plasmodium berghei Response to Chloroquine and Artemisinin. PLoS One 2015; 10:e0128212. [PMID: 26010448 PMCID: PMC4444287 DOI: 10.1371/journal.pone.0128212] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 04/23/2015] [Indexed: 11/19/2022] Open
Abstract
Malaria is one of the most devastating parasitic diseases worldwide. Plasmodium drug resistance remains a major challenge to malaria control and has led to the re-emergence of the disease. Chloroquine (CQ) and artemisinin (ART) are thought to exert their anti-malarial activity inducing cytotoxicity in the parasite by blocking heme degradation (for CQ) and increasing oxidative stress. Besides the contribution of the CQ resistance transporter (PfCRT) and the multidrug resistant gene (pfmdr), CQ resistance has also been associated with increased parasite glutathione (GSH) levels. ART resistance was recently shown to be associated with mutations in the K13-propeller protein. To analyze the role of GSH levels in CQ and ART resistance, we generated transgenic Plasmodium berghei parasites either deficient in or overexpressing the gamma-glutamylcysteine synthetase gene (pbggcs) encoding the rate-limiting enzyme in GSH biosynthesis. These lines produce either lower (pbggcs-ko) or higher (pbggcs-oe) levels of GSH than wild type parasites. In addition, GSH levels were determined in P. berghei parasites resistant to CQ and mefloquine (MQ). Increased GSH levels were detected in both, CQ and MQ resistant parasites, when compared to the parental sensitive clone. Sensitivity to CQ and ART remained unaltered in both pgggcs-ko and pbggcs-oe parasites when tested in a 4 days drug suppressive assay. However, recrudescence assays after the parasites have been exposed to a sub-lethal dose of ART showed that parasites with low levels of GSH are more sensitive to ART treatment. These results suggest that GSH levels influence Plasmodium berghei response to ART treatment.
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Soares RR, da Silva JMF, Carlos BC, da Fonseca CC, de Souza LSA, Lopes FV, de Paula Dias RM, Moreira POL, Abramo C, Viana GHR, de Pila Varotti F, da Silva AD, Scopel KKG. New quinoline derivatives demonstrate a promising antimalarial activity against Plasmodium falciparum in vitro and Plasmodium berghei in vivo. Bioorg Med Chem Lett 2015; 25:2308-13. [PMID: 25920564 DOI: 10.1016/j.bmcl.2015.04.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 04/01/2015] [Accepted: 04/08/2015] [Indexed: 11/19/2022]
Abstract
Malaria continues to be an important public health problem in the world. Nowadays, the widespread parasite resistance to many drugs used in antimalarial therapy has made the effective treatment of cases and control of the disease a constant challenge. Therefore, the discovery of new molecules with good antimalarial activity and tolerance to human use can be really important in the further treatment of the disease. In this study we have investigated the antiplasmodial activity of 10 synthetic compounds derived from quinoline, five of them combined to sulfonamide and five to the hydrazine or hydrazide group. The compounds were evaluated according to their cytotoxicity against HepG2 and HeLa cell lines, their antimalarial activity against CQ-sensitive and CQ-resistant Plasmodium falciparum strains and, finally, their schizonticide blood action in mice infected with Plasmodium berghei NK65. The compounds exhibited no cytotoxic action in HepG2 and HeLa cell lines when tested up to a concentration of 100 μg/mL. In addition, the hydrazine or hydrazide derivative compounds were less cytotoxic against cell lines and more active against CQ-sensitive and CQ-resistant P. falciparum strains, showing high SI (>1000 when SI was calculated using the CC50 from the 3D7 strain as reference). When tested in vivo, the hydrazine derivative 1f compound showed activity against the development of blood parasites similar to that observed with CQ, the reference drug. Interestingly, the 1f compound demonstrated the best LipE value (4.84) among all those tested in vivo. Considering the in vitro and in vivo activities of the compounds studied here and the LipE values, we believe the 1f compound to be the most promising molecule for further studies in antimalarial chemotherapy.
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Affiliation(s)
- Roberta Reis Soares
- Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil.
| | - José Marcio Fernandes da Silva
- Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil.
| | - Bianca Cecheto Carlos
- Instituto de Biotecnologia (IBTEC), Universidade Estadual Paulista, Alameda dos Tecomarias, s/n, 18607-440 Botucatu, SP, Brazil.
| | - Camila Campos da Fonseca
- Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil.
| | - Laila Salomé Araújo de Souza
- Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil.
| | - Fernanda Valério Lopes
- Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil.
| | - Rafael Mafra de Paula Dias
- Instituto de Química de São Carlos, Universidade de São Paulo. Avenida João Dagnone, n° 1100, Jardim Santa Angelina, 13563-120 São Carlos, SP, Brazil.
| | - Paulo Otávio Lourenço Moreira
- Núcleo de Pesquisa em Química Biológica (NQBio), Universidade de São João Del Rei, Rua Sebastião Gonçalves Coelho, Chanadour, 35501-296 Divinópolis, MG, Brazil.
| | - Clarice Abramo
- Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil.
| | - Gustavo Henrique Ribeiro Viana
- Núcleo de Pesquisa em Química Biológica (NQBio), Universidade de São João Del Rei, Rua Sebastião Gonçalves Coelho, Chanadour, 35501-296 Divinópolis, MG, Brazil.
| | - Fernando de Pila Varotti
- Núcleo de Pesquisa em Química Biológica (NQBio), Universidade de São João Del Rei, Rua Sebastião Gonçalves Coelho, Chanadour, 35501-296 Divinópolis, MG, Brazil.
| | - Adilson David da Silva
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil.
| | - Kézia Katiani Gorza Scopel
- Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer s/n, Martelos, 36036-900 Juiz de Fora, MG, Brazil; Departamento of Global Health, University of South Florida, 3720 Spectrun Blvd, suit 304, Tampa, FL 33612, USA.
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Singh AK, Rajendran V, Pant A, Ghosh PC, Singh N, Latha N, Garg S, Pandey KC, Singh BK, Rathi B. Design, synthesis and biological evaluation of functionalized phthalimides: A new class of antimalarials and inhibitors of falcipain-2, a major hemoglobinase of malaria parasite. Bioorg Med Chem 2015; 23:1817-27. [DOI: 10.1016/j.bmc.2015.02.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 02/09/2015] [Accepted: 02/17/2015] [Indexed: 10/23/2022]
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Shah M, Omosun Y, Lal A, Odero C, Gatei W, Otieno K, Gimnig JE, ter Kuile F, Hawley WA, Nahlen B, Kariuki S, Walker E, Slutsker L, Hamel M, Shi YP. Assessment of molecular markers for anti-malarial drug resistance after the introduction and scale-up of malaria control interventions in western Kenya. Malar J 2015; 14:75. [PMID: 25889220 PMCID: PMC4331436 DOI: 10.1186/s12936-015-0588-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/27/2015] [Indexed: 12/29/2022] Open
Abstract
Background Although it is well known that drug pressure selects for drug-resistant parasites, the role of transmission reduction by insecticide-treated bed nets (ITNs) on drug resistance remains unclear. In this study, the drug resistance profile of current and previous first-line anti-malarials in Kenya was assessed within the context of drug policy change and scale-up of ITNs. National first-line treatment changed from chloroquine (CQ) to sulphadoxine-pyrimethamine (SP) in 1998 and to artemether-lumefantrine (AL) in 2004. ITN use was scaled-up in the Asembo, Gem and Karemo areas of western Kenya in 1997, 1999 and 2006, respectively. Methods Smear-positive samples (N = 253) collected from a 2007 cross-sectional survey among children in Asembo, Gem and Karemo were genotyped for mutations in pfcrt and pfmdr1 (CQ), dhfr and dhps (SP), and at pfmdr-N86 and the gene copy number in pfmdr1 (lumefantrine). Results were compared among the three geographic areas in 2007 and to retrospective molecular data from children in Asembo in 2001. Results In 2007, 69 and 85% of samples harboured the pfmdr1-86Y mutation and dhfr/dhps quintuple mutant, respectively, with no significant differences by study area. However, the prevalence of the pfcrt-76T mutation differed significantly among areas (p <0.02), between 76 and 94%, with the highest prevalence in Asembo. Several 2007 samples carried mutations at dhfr-164L, dhps-436A, or dhps-613T. From 2001 to 2007, there were significant increases in the pfcrt-76T mutation from 82 to 94% (p <0.03), dhfr/dhps quintuple mutant from 62 to 82% (p <0.03), and an increase in the septuple CQ and SP combined mutant haplotype, K76Y86I51R59N108G437E540, from 28 to 39%. The prevalence of the pfmdr1-86Y mutation remained unchanged. All samples were single copy for pfmdr1. Conclusions Molecular markers associated with lumefantrine resistance were not detected in 2007. More recent samples will be needed to detect any selective effects by AL. The prevalence of CQ and SP resistance markers increased from 2001 to 2007 in the absence of changes in transmission intensity. In 2007, only the prevalence of pfcrt-76T mutation differed among study areas of varying transmission intensity. Resistant parasites were most likely selected by sustained drug pressure from the continued use of CQ, SP, and mechanistically similar drugs, such as amodiaquine and cotrimoxazole. There was no clear evidence that differences in transmission intensity, as a result of ITN scale-up, influenced the prevalence of drug resistance molecular markers. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0588-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Monica Shah
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. .,Atlanta Research and Education Foundation, Atlanta, GA, USA.
| | - Yusuf Omosun
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. .,Atlanta Research and Education Foundation, Atlanta, GA, USA.
| | - Ashima Lal
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. .,Atlanta Research and Education Foundation, Atlanta, GA, USA.
| | - Christopher Odero
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | - Wangeci Gatei
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | - Kephas Otieno
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | - John E Gimnig
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | | | - William A Hawley
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. .,UNICEF, Child Survival and Development Cluster, Jakarta, Indonesia.
| | | | - Simon Kariuki
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | | | - Laurence Slutsker
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | - Mary Hamel
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. .,Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | - Ya Ping Shi
- Malaria Branch and Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
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Patel K, Simpson JA, Batty KT, Zaloumis S, Kirkpatrick CM. Modelling the time course of antimalarial parasite killing: a tour of animal and human models, translation and challenges. Br J Clin Pharmacol 2015; 79:97-107. [PMID: 24251882 PMCID: PMC4294080 DOI: 10.1111/bcp.12288] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 10/31/2013] [Indexed: 01/06/2023] Open
Abstract
Malaria remains a global public health concern and current treatment options are suboptimal in some clinical settings. For effective chemotherapy, antimalarial drug concentrations must be sufficient to remove completely all of the parasites in the infected host. Optimized dosing therefore requires a detailed understanding of the time course of antimalarial response, whilst simultaneously considering the parasite life cycle and host immune elimination. Recently, the World Health Organization (WHO) has recommended the development of mathematical models for understanding better antimalarial drug resistance and management. Other international groups have also suggested that mechanistic pharmacokinetic (PK) and pharmacodynamic (PD) models can support the rationalization of antimalarial dosing strategies. At present, artemisinin-based combination therapy (ACT) is recommended as first line treatment of falciparum malaria for all patient groups. This review summarizes the PK-PD characterization of artemisinin derivatives and other partner drugs from both preclinical studies and human clinical trials. We outline the continuous and discrete time models that have been proposed to describe antimalarial activity on specific stages of the parasite life cycle. The translation of PK-PD predictions from animals to humans is considered, because preclinical studies can provide rich data for detailed mechanism-based modelling. While similar sampling techniques are limited in clinical studies, PK-PD models can be used to optimize the design of experiments to improve estimation of the parameters of interest. Ultimately, we propose that fully developed mechanistic models can simulate and rationalize ACT or other treatment strategies in antimalarial chemotherapy.
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Affiliation(s)
- Kashyap Patel
- Centre for Medicine Use and Safety, Monash UniversityMelbourne, VIC, Australia
| | - Julie A Simpson
- Centre for Molecular, Environmental, Genetic & Analytic Epidemiology, Melbourne School of Population and Global Health, The University of MelbourneMelbourne, VIC, Australia
| | - Kevin T Batty
- School of Pharmacy, Curtin UniversityBentley, WA, Australia
- West Coast InstituteJoondalup, WA, Australia
| | - Sophie Zaloumis
- Centre for Molecular, Environmental, Genetic & Analytic Epidemiology, Melbourne School of Population and Global Health, The University of MelbourneMelbourne, VIC, Australia
| | - Carl M Kirkpatrick
- Centre for Medicine Use and Safety, Monash UniversityMelbourne, VIC, Australia
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Zaloumis SG, Tarning J, Krishna S, Price RN, White NJ, Davis TME, McCaw JM, Olliaro P, Maude RJ, Kremsner P, Dondorp A, Gomes M, Barnes K, Simpson JA. Population pharmacokinetics of intravenous artesunate: a pooled analysis of individual data from patients with severe malaria. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2014; 3:e145. [PMID: 25372510 PMCID: PMC4259998 DOI: 10.1038/psp.2014.43] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 08/28/2014] [Indexed: 11/09/2022]
Abstract
There are ~660,000 deaths from severe malaria each year. Intravenous artesunate (i.v. ARS) is the first-line treatment in adults and children. To optimize the dosing regimen of i.v. ARS, the largest pooled population pharmacokinetic study to date of the active metabolite dihydroartemisinin (DHA) was performed. The pooled dataset consisted of 71 adults and 195 children with severe malaria, with a mixture of sparse and rich sampling within the first 12 h after drug administration. A one-compartment model described the population pharmacokinetics of DHA adequately. Body weight had the greatest impact on DHA pharmacokinetics, resulting in lower DHA exposure for smaller children (6–10 kg) than adults. Post hoc estimates of DHA exposure were not significantly associated with parasitological outcomes. Comparable DHA exposure in smaller children and adults after i.v. ARS was achieved under a dose modification for intramuscular ARS proposed in a separate analysis of children.
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Affiliation(s)
- S G Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - J Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - S Krishna
- Institute for Infection and Immunity, St. George's, University of London, London, UK
| | - R N Price
- Centre for Clinical Vaccinology and Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - N J White
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - T M E Davis
- School of Medicine and Pharmacology, Fremantle Hospital, University of Western Australia, Fremantle, Australia
| | - J M McCaw
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - P Olliaro
- 1] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK [2] World Health Organization, Genève, Switzerland
| | - R J Maude
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - P Kremsner
- 1] Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon [2] Institute for Tropical Medicine, Department of Parasitology, University of Tübingen, Tübingen, Germany
| | - A Dondorp
- 1] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK [2] Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - M Gomes
- World Health Organization, Genève, Switzerland
| | - K Barnes
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - J A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
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79
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Grynberg S, Lachish T, Kopel E, Meltzer E, Schwartz E. Artemether-lumefantrine compared to atovaquone-proguanil as a treatment for uncomplicated Plasmodium falciparum malaria in travelers. Am J Trop Med Hyg 2014; 92:13-7. [PMID: 25371188 DOI: 10.4269/ajtmh.14-0249] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Atovaquone-proguanil (AP) and artemether-lumefantrine (AL) are both treatments for uncomplicated Plasmodium falciparum malaria, but comparative clinical trials are lacking. We performed a retrospective analysis, comparing treatment failure and fever clearance time in non-immune travelers with uncomplicated P. falciparum malaria, treated with AP or AL. Sixty-nine patients were included during 2001-2013: 44 in the AP group and 25 in the AL group. Treatment failure was observed in 6 of 44 (13.6%) and 1 of 25 (4.0%) patients in the AP and AL groups, respectively. Six treatment failures were observed in travelers from West Africa. Fever clearance time was 44 ± 23 h in AL group versus 77 ± 28 h in AP group, (P < 0.001). Hospitalization time was significantly shorter in the AL group; 3.8 + 1.3 versus 5.1 + 2.8 days in the AP group (P = 0.04) In conclusion, travelers with uncomplicated P. falciparum malaria recover faster on AL than on AP. The AL should probably be the drug of choice for this population.
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Affiliation(s)
- Shirly Grynberg
- The Center of Geographic Medicine and Tropical Diseases, Sheba Medical Center, Tel Hashomer, Israel; The Infectious Diseases Unit, Shaare-Zedek Medical Center, Jerusalem, Israel; The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tamar Lachish
- The Center of Geographic Medicine and Tropical Diseases, Sheba Medical Center, Tel Hashomer, Israel; The Infectious Diseases Unit, Shaare-Zedek Medical Center, Jerusalem, Israel; The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eran Kopel
- The Center of Geographic Medicine and Tropical Diseases, Sheba Medical Center, Tel Hashomer, Israel; The Infectious Diseases Unit, Shaare-Zedek Medical Center, Jerusalem, Israel; The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eyal Meltzer
- The Center of Geographic Medicine and Tropical Diseases, Sheba Medical Center, Tel Hashomer, Israel; The Infectious Diseases Unit, Shaare-Zedek Medical Center, Jerusalem, Israel; The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eli Schwartz
- The Center of Geographic Medicine and Tropical Diseases, Sheba Medical Center, Tel Hashomer, Israel; The Infectious Diseases Unit, Shaare-Zedek Medical Center, Jerusalem, Israel; The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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80
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Oguche S, Okafor HU, Watila I, Meremikwu M, Agomo P, Ogala W, Agomo C, Ntadom G, Banjo O, Okuboyejo T, Ogunrinde G, Odey F, Aina O, Sofola T, Sowunmi A. Efficacy of artemisinin-based combination treatments of uncomplicated falciparum malaria in under-five-year-old Nigerian children. Am J Trop Med Hyg 2014; 91:925-935. [PMID: 25246693 PMCID: PMC4228889 DOI: 10.4269/ajtmh.13-0248] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/10/2014] [Indexed: 11/10/2022] Open
Abstract
The efficacy of 3-day regimens of artemether-lumefantrine and artesunate-amodiaquine were evaluated in 747 children < 5 years of age with uncomplicated malaria from six geographical areas of Nigeria. Fever clearance was significantly faster (P = 0.006) and the proportion of children with parasitemia 1 day after treatment began was significantly lower (P = 0.016) in artesunate-amodiaquine-compared with artemether-lumefantrine-treated children. Parasite clearance times were similar with both treatments. Overall efficacy was 96.3% (95% confidence interval [CI] 94.5-97.6%), and was similar for both regimens. Polymerase chain reaction-corrected parasitologic cure rates on Day 28 were 96.9% (95% CI 93.9-98.2%) and 98.3% (95% CI 96.1-99.3%) for artemether-lumefantrine and artesunate-amodiaquine, respectively. Gametocyte carriage post treatment was significantly lower than pretreatment (P < 0.0001). In anemic children, mean time to recovery from anemia was 10 days (95% CI 9.04-10.9) and was similar for both regimens. Both treatments were well tolerated and are safe and efficacious treatments of uncomplicated falciparum malaria in young Nigerian children.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Akintunde Sowunmi
- Antimalarial Therapeutic Efficacy Monitoring Group, The Federal Ministry of Health, Abuja, Nigeria
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81
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Efficacy of intravenous methylene blue, intravenous artesunate, and their combination in preclinical models of malaria. Malar J 2014; 13:415. [PMID: 25336091 PMCID: PMC4210502 DOI: 10.1186/1475-2875-13-415] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/17/2014] [Indexed: 11/16/2022] Open
Abstract
Background Intravenous artesunate (IV AS) is the present treatment of choice for severe malaria, but development of artemisinin resistance indicates that a further agent will be needed. Methylene blue (MB) is an approved human agent for IV and oral use, and is already being investigated for oral treatment of uncomplicated malaria. To initiate investigation of IV MB for severe malaria, the efficacy of IV MB was compared to IV AS and to their combination in rat and non-human primate malaria models. Methods IV MB was compared to IV AS and to their combination in the Plasmodium berghei-infected rat, a self-curing model; the Plasmodium falciparum-infected Aotus monkey, a fatal model; and the Plasmodium cynomolgi-infected rhesus monkey, a fatal model. Key endpoints were clearance of all parasites from the blood and cure (clearance without recrudescence). Results In rats, the minimal dose of individual drugs and their combination that cleared parasites from all animals was 20 mg IV MB/kg/day, 60 mg IV AS/kg/day and 10 mg IV MB/kg/day plus 30 mg IV AS/kg/day. In Aotus, 8 mg IV MB/kg/day and 8 mg IV AS/kg/day each cured two of three monkeys by one day after therapy, and the third monkey in each group was cured two days later. The combination of both drugs did not result in superior efficacy. In rhesus, 8 mg IV MB/kg/day and 8 mg IV AS/kg/day performed comparably: parasite clearance occurred by day 3 of therapy, although only one of four animals in each dose group cured. Eight mg/kg/day of both drugs in combination was 100% successful: all four of four animals cured. Conclusions In each of the three animal models, the efficacy of IV MB was approximately equal to that of standard of care IV AS. In the rat and rhesus models, the combination was more effective than either single agent. This preclinical data suggests that IV MB, alone or in combination with IV AS, is effective against Plasmodium spp. and can be evaluated in severe malaria models.
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82
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Ghansah A, Amenga-Etego L, Amambua-Ngwa A, Andagalu B, Apinjoh T, Bouyou-Akotet M, Cornelius V, Golassa L, Andrianaranjaka VH, Ishengoma D, Johnson K, Kamau E, Maïga-Ascofaré O, Mumba D, Tindana P, Tshefu-Kitoto A, Randrianarivelojosia M, William Y, Kwiatkowski DP, Djimde AA. Monitoring parasite diversity for malaria elimination in sub-Saharan Africa. Science 2014; 345:1297-8. [PMID: 25214619 DOI: 10.1126/science.1259423] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The African continent continues to bear the greatest burden of malaria and the greatest diversity of parasites, mosquito vectors, and human victims. The evolutionary plasticity of malaria parasites and their vectors is a major obstacle to eliminating the disease. Of current concern is the recently reported emergence of resistance to the front-line drug, artemisinin, in South-East Asia in Plasmodium falciparum, which calls for preemptive surveillance of the African parasite population for genetic markers of emerging drug resistance. Here we describe the Plasmodium Diversity Network Africa (PDNA), which has been established across 11 countries in sub-Saharan Africa to ensure that African scientists are enabled to work together and to play a key role in the global effort for tracking and responding to this public health threat.
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Affiliation(s)
- Anita Ghansah
- Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | | | | | - Ben Andagalu
- KEMRI/United States Army Medical Research Unit-Kenya, Kisumu, Nairobi, Kenya
| | - Tobias Apinjoh
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, Cameroon
| | - Marielle Bouyou-Akotet
- Department of Parasitology Mycology, Faculty of Medicine, Université des Sciences de la Sante, Libreville, Gabon
| | - Victoria Cornelius
- MRC Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University and Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Deus Ishengoma
- National Institute for Medical Research, Tanga, Tanzania
| | - Kimberly Johnson
- MRC Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Edwin Kamau
- KEMRI/United States Army Medical Research Unit-Kenya, Kisumu, Nairobi, Kenya
| | - Oumou Maïga-Ascofaré
- Malaria Research and Training Centre (MRTC), Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali. Bernhard Nocht Institute for Tropical Medicine in Hamburg, Germany
| | - Dieudonne Mumba
- Institut National de Recherche Biomédicale, Ecole de Santé Publique/Faculté de Médecine/Université de Kinshasa, Kinshasa, Democratic Republic of the Congo
| | | | - Antoinette Tshefu-Kitoto
- Institut National de Recherche Biomédicale, Ecole de Santé Publique/Faculté de Médecine/Université de Kinshasa, Kinshasa, Democratic Republic of the Congo
| | | | - Yavo William
- Malaria Research and Control Center, National Institute of Public Health, Abidjan, Ivory Coast
| | - Dominic P Kwiatkowski
- MRC Centre for Genomics and Global Health, University of Oxford, Oxford, UK. Wellcome Trust Sanger Institute, Hinxton, UK
| | - Abdoulaye A Djimde
- Malaria Research and Training Centre (MRTC), Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali. Wellcome Trust Sanger Institute, Hinxton, UK.
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83
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Delayed parasite clearance after treatment with dihydroartemisinin-piperaquine in Plasmodium falciparum malaria patients in central Vietnam. Antimicrob Agents Chemother 2014; 58:7049-55. [PMID: 25224002 DOI: 10.1128/aac.02746-14] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reduced susceptibility of Plasmodium falciparum toward artemisinin derivatives has been reported from the Thai-Cambodian and Thai-Myanmar borders. Following increasing reports from central Vietnam of delayed parasite clearance after treatment with dihydroartemisinin-piperaquine (DHA-PPQ), the current first-line treatment, we carried out a study on the efficacy of this treatment. Between September 2012 and February 2013, we conducted a 42-day in vivo and in vitro efficacy study in Quang Nam Province. Treatment was directly observed, and blood samples were collected twice daily until parasite clearance. In addition, genotyping, quantitative PCR (qPCR), and in vitro sensitivity testing of isolates was performed. The primary endpoints were parasite clearance rate and time. The secondary endpoints included PCR-corrected and uncorrected cure rates, qPCR clearance profiles, in vitro sensitivity results (for chloroquine, dihydroartemisinin, and piperaquine), and genotyping for mutations in the Kelch 13 propeller domain. Out of 672 screened patients, 95 were recruited and 89 available for primary endpoint analyses. The median parasite clearance time (PCT) was 61.7 h (interquartile range [IQR], 47.6 to 83.2 h), and the median parasite clearance rate had a slope half-life of 6.2 h (IQR, 4.4 to 7.5 h). The PCR-corrected efficacy rates were estimated at 100% at day 28 and 97.7% (95% confidence interval, 91.2% to 99.4%) at day 42. At day 3, the P. falciparum prevalence by qPCR was 2.5 times higher than that by microscopy. The 50% inhibitory concentrations (IC50s) of isolates with delayed clearance times (≥ 72 h) were significantly higher than those with normal clearance times for all three drugs. Delayed parasite clearance (PCT, ≥ 72 h) was significantly higher among day 0 samples carrying the 543 mutant allele (47.8%) than those carrying the wild-type allele (1.8%; P = 0.048). In central Vietnam, the efficacy of DHA-PPQ is still satisfactory, but the parasite clearance time and rate are indicative of emerging artemisinin resistance. (This study has been registered at ClinicalTrials.gov under registration no. NCT01775592.).
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84
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A first-in-human randomized, double-blind, placebo-controlled, single- and multiple-ascending oral dose study of novel Imidazolopiperazine KAF156 to assess its safety, tolerability, and pharmacokinetics in healthy adult volunteers. Antimicrob Agents Chemother 2014; 58:6437-43. [PMID: 25136017 PMCID: PMC4249437 DOI: 10.1128/aac.03478-14] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
KAF156 belongs to a new class of antimalarial, the imidazolopiperazines, and is currently in clinical development for the treatment of uncomplicated malaria. This first-in-human, single- and multiple-ascending-dose study in 70 healthy male volunteers determined the maximum oral dose of KAF156 tolerated by healthy adults and derived pharmacokinetic data (including preliminary food effect) to enable dose calculations for malaria patients. KAF156 was studied in single-dose cohorts (10 to 1,200 mg, including one 400-mg food effect cohort (4 to 10 subjects/cohort), and in multiple-dose cohorts (60 to 600 mg once daily for 3 days; 8 subjects/cohort). The follow-up period was 6 to 14 days after the last dose. KAF156 was tolerated, with self-limited mild to moderate gastrointestinal and neurological adverse events. In treated subjects after single doses, headache (n = 4; 11.1%), diarrhea (n = 3; 8.3%), dizziness (n = 3; 8.3%), and abdominal pain (n = 2; 5.6%) were the most common adverse events. Headache (n = 4; 16.7%), nausea (n = 3; 12.5%), upper respiratory tract infection (n = 3; 12.5%), and dizziness (n = 2; 8.3%) were the most common adverse events following multiple doses. KAF156 time to maximum concentration (Tmax) was between 1.0 and 6.0 h. Both the area under the concentration-time curve (AUC) and maximum concentration (Cmax) increased more than dose-proportionally in both single- and multiple-ascending-dose cohorts (terminal half-life, 42.5 to 70.7 h). There was no significant accumulation over 3-day repeated administration. The extent of absorption was not significantly affected by food at a single dose of 400 mg, while mean Cmax decreased from 778 ng/ml to 627 ng/ml and Tmax was delayed from a median of 3.0 h under fasting conditions to 6.0 h under fed conditions. Renal elimination is a minor route.
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85
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Simpson JA, Zaloumis S, DeLivera AM, Price RN, McCaw JM. Making the most of clinical data: reviewing the role of pharmacokinetic-pharmacodynamic models of anti-malarial drugs. AAPS JOURNAL 2014; 16:962-74. [PMID: 25056904 DOI: 10.1208/s12248-014-9647-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/02/2014] [Indexed: 12/20/2022]
Abstract
Mechanistic within-host models integrating blood anti-malarial drug concentrations with the parasite-time profile provide a valuable decision tool for determining dosing regimens for anti-malarial treatments, as well as a formative component of population-level drug resistance models. We reviewed published anti-malarial pharmacokinetic-pharmacodynamic models to identify the challenges for these complex models where parameter estimation from clinical field data is limited. The inclusion of key pharmacodynamic processes in the mechanistic structure adopted varies considerably. These include the life cycle of the parasite within the red blood cell, the action of the anti-malarial on a specific stage of the life cycle, and the reduction in parasite growth associated with immunity. With regard to estimation of the pharmacodynamic parameters, the majority of studies simply compared descriptive summaries of the simulated outputs to published observations of host and parasite responses from clinical studies. Few studies formally estimated the pharmacodynamic parameters within a rigorous statistical framework using observed individual patient data. We recommend three steps in the development and evaluation of these models. Firstly, exploration through simulation to assess how the different parameters influence the parasite dynamics. Secondly, application of a simulation-estimation approach to determine whether the model parameters can be estimated with reasonable precision based on sampling designs that mimic clinical efficacy studies. Thirdly, fitting the mechanistic model to the clinical data within a Bayesian framework. We propose that authors present the model both schematically and in equation form and give a detailed description of each parameter, including a biological interpretation of the parameter estimates.
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Affiliation(s)
- Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia,
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Ex vivo activity of endoperoxide antimalarials, including artemisone and arterolane, against multidrug-resistant Plasmodium falciparum isolates from Cambodia. Antimicrob Agents Chemother 2014; 58:5831-40. [PMID: 25049252 DOI: 10.1128/aac.02462-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Novel synthetic endoperoxides are being evaluated as new components of artemisinin combination therapies (ACTs) to treat artemisinin-resistant Plasmodium falciparum malaria. We conducted blinded ex vivo activity testing of fully synthetic (OZ78 and OZ277) and semisynthetic (artemisone, artemiside, artesunate, and dihydroartemisinin) endoperoxides in the histidine-rich protein 2 enzyme-linked immunosorbent assay against 200 P. falciparum isolates from areas of artemisinin-resistant malaria in western and northern Cambodia in 2009 and 2010. The order of potency and geometric mean (GM) 50% inhibitory concentrations (IC50s) were as follows: artemisone (2.40 nM) > artesunate (8.49 nM) > dihydroartemisinin (11.26 nM) > artemiside (15.28 nM) > OZ277 (31.25 nM) > OZ78 (755.27 nM). Ex vivo activities of test endoperoxides positively correlated with dihydroartemisinin and artesunate. The isolates were over 2-fold less susceptible to dihydroartemisinin than the artemisinin-sensitive P. falciparum W2 clone and showed sensitivity comparable to those with test endoperoxides and artesunate, with isolate/W2 IC50 susceptibility ratios of <2.0. All isolates had P. falciparum chloroquine resistance transporter mutations, with negative correlations in sensitivity to endoperoxides and chloroquine. The activities of endoperoxides (artesunate, dihydroartemisinin, OZ277, and artemisone) significantly correlated with that of the ACT partner drug, mefloquine. Isolates had mutations associated with clinical resistance to mefloquine, with 35% prevalence of P. falciparum multidrug resistance gene 1 (pfmdr1) amplification and 84.5% occurrence of the pfmdr1 Y184F mutation. GM IC50s for mefloquine, lumefantrine, and endoperoxides (artesunate, dihydroartemisinin, OZ277, OZ78, and artemisone) correlated with pfmdr1 copy number. Given that current ACTs are failing potentially from reduced sensitivity to artemisinins and partner drugs, newly identified mutations associated with artemisinin resistance reported in the literature and pfmdr1 mutations should be examined for their combined contributions to emerging ACT resistance.
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87
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Tinto H, Bonkian LN, Nana LA, Yerbanga I, Lingani M, Kazienga A, Valéa I, Sorgho H, Kpoda H, Guiguemdé TR, Ouédraogo JB, Mens PF, Schallig H, D’Alessandro U. Ex vivo anti-malarial drugs sensitivity profile of Plasmodium falciparum field isolates from Burkina Faso five years after the national policy change. Malar J 2014; 13:207. [PMID: 24885950 PMCID: PMC4049403 DOI: 10.1186/1475-2875-13-207] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/21/2014] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND The recent reports on the decreasing susceptibility of Plasmodium falciparum to artemisinin derivatives along the Thailand and Myanmar border are worrying. Indeed it may spread to India and then Africa, repeating the same pattern observed for chloroquine resistance. Therefore, it is essential to start monitoring P. falciparum sensitivity to artemisinin derivatives and its partner drugs in Africa. Efficacy of AL and ASAQ were tested by carrying out an in vivo drug efficacy test, with an ex vivo study against six anti-malarial drugs nested into it. Results of the latter are reported here. METHODS Plasmodium falciparum ex-vivo susceptibility to chloroquine (CQ), quinine (Q), lumefantrine (Lum), monodesethylamodiaquine (MDA), piperaquine (PPQ) and dihydroartemisinin (DHA) was investigated in children (6 months - 15 years) with a parasitaemia of at least ≥4,000/μl. The modified isotopic microtest technique was used. The results of cellular proliferation were analysed using ICEstimator software to determine the 50% inhibitory concentration (IC50) values. RESULTS DHA was the most potent among the 6 drugs tested, with IC50 values ranging from 0.8 nM to 0.9 nM (Geometric mean IC50 = 0.8 nM; 95% CI [0.8 - 0.9]). High IC50 values ranged between 0.8 nM to 166.1 nM were reported for lumefantrine (Geometric mean IC50 = 25.1 nM; 95% CI [22.4 - 28.2]). MDA and Q IC50s were significantly higher in CQ-resistant than in CQ-sensitive isolates (P = 0.0001). However, the opposite occurred for Lum and DHA (P < 0.001). No difference was observed for PPQ. CONCLUSION Artemisinin derivatives are still very efficacious in Burkina Faso and DHA-PPQ seems a valuable alternative ACT. The high lumefantrine IC50 found in this study is worrying as it may indicate a decreasing efficacy of one of the first-line treatments. This should be further investigated and monitored over time with large in vivo and ex vivo studies that will include also plasma drug measurements.
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Affiliation(s)
- Halidou Tinto
- Unité de Recherche sur le Paludisme et Maladies Tropicales Négligées, Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Institut de Recherche en Sciences de la Santé/Direction Régionale de l’Ouest (IRSS/DRO), Bobo-Dioulasso, Burkina Faso
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Léa N Bonkian
- Unité de Recherche sur le Paludisme et Maladies Tropicales Négligées, Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Louis A Nana
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Isidore Yerbanga
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Moussa Lingani
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Adama Kazienga
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Innocent Valéa
- Unité de Recherche sur le Paludisme et Maladies Tropicales Négligées, Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Hermann Sorgho
- Institut de Recherche en Sciences de la Santé/Direction Régionale de l’Ouest (IRSS/DRO), Bobo-Dioulasso, Burkina Faso
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Hervé Kpoda
- Unité de Recherche sur le Paludisme et Maladies Tropicales Négligées, Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Tinga Robert Guiguemdé
- Unité de Recherche sur le Paludisme et Maladies Tropicales Négligées, Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
- Institut Supérieur des Sciences de la Santé (INSSA), Bobo Dioulasso, Burkina Faso
| | - Jean Bosco Ouédraogo
- Unité de Recherche sur le Paludisme et Maladies Tropicales Négligées, Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Institut de Recherche en Sciences de la Santé/Direction Régionale de l’Ouest (IRSS/DRO), Bobo-Dioulasso, Burkina Faso
| | - Petronella F Mens
- Royal Tropical Institute/Koninklijk Instituut voor de Tropen (KIT), Amsterdam, The Netherlands
| | - Henk Schallig
- Royal Tropical Institute/Koninklijk Instituut voor de Tropen (KIT), Amsterdam, The Netherlands
| | - Umberto D’Alessandro
- Medical Research Council Unit, The Gambia, Disease Control & Elimination Theme, Fajara, The Gambia
- Prince Leopold Institute of Tropical Medicine, Antwerp, Belgium
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Muhamad P, Chaijaroenkul W, Phompradit P, Rueangweerayut R, Tippawangkosol P, Na-Bangchang K. Polymorphic patterns of pfcrt and pfmdr1 in Plasmodium falciparum isolates along the Thai-Myanmar border. Asian Pac J Trop Biomed 2014; 3:931-5. [PMID: 24093782 DOI: 10.1016/s2221-1691(13)60181-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 10/21/2013] [Accepted: 11/20/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVE To investigate the distribution and patterns of pfcrt and pfmdr1 polymorphisms in Plasmodium falciparum (P. falciparum) isolates collected from the malaria endemic area of Thailand along Thai-Myanmar border. METHODS Dried blood spot samples were collected from 172 falciparum malaria patients prior received treatment. The samples were extracted using chelex to obtain parasite DNA. PCR-RFLP was employed to detect pfcrt mutation at codons 76, 220, 271, 326, 356 and 371, and the pfmdr1 mutation at codon 86. Pfmdr1 gene copy number was determined by SYBR Green I real-time PCR. RESULTS Mutant alleles of pfcrt and wild type allele of pfmdr1 were found in almost all samples. Pfmdr1 gene copy number in isolates collected from all areas ranged from 1.0 to 5.0 copies and proportion of isolates carrying>1 gene copies was 38.1%. The distribution and patterns of pfcrt and pfmdr1 mutations were similar in P. falciparum isolates from all areas. However, significant differences in both number of pfmdr1 copies and prevalence of isolates carrying>1 gene copies were observed among isolates collected from different areas. The median pfmdr1 copy number in P. falciparum collected from Kanchanaburi and Mae Hongson were 2.5 and 2.0, respectively and more than half of the isolates carried>1 gene copies. CONCLUSIONS The observation of pfmdr1 wild type and increasing of gene copy number may suggest declining of artesunate-mefloquine treatment efficacy in P. falciparum isolates in this border area.
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Affiliation(s)
- Phunuch Muhamad
- Chulabhorn International College of Medicine, Thammasat University, Patumthani, Thailand
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89
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Lon C, Manning JE, Vanachayangkul P, So M, Sea D, Se Y, Gosi P, Lanteri C, Chaorattanakawee S, Sriwichai S, Chann S, Kuntawunginn W, Buathong N, Nou S, Walsh DS, Tyner SD, Juliano JJ, Lin J, Spring M, Bethell D, Kaewkungwal J, Tang D, Chuor CM, Satharath P, Saunders D. Efficacy of two versus three-day regimens of dihydroartemisinin-piperaquine for uncomplicated malaria in military personnel in northern Cambodia: an open-label randomized trial. PLoS One 2014; 9:e93138. [PMID: 24667662 PMCID: PMC3965521 DOI: 10.1371/journal.pone.0093138] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/27/2014] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Emerging antimalarial drug resistance in mobile populations remains a significant public health concern. We compared two regimens of dihydroartemisinin-piperaquine in military and civilians on the Thai-Cambodian border to evaluate national treatment policy. METHODS Efficacy and safety of two and three-day regimens of dihydroartemisinin-piperaquine were compared as a nested open-label evaluation within a malaria cohort study in 222 otherwise healthy volunteers (18% malaria-infected at baseline). The first 80 volunteers with slide-confirmed Plasmodium falciparum or vivax malaria were randomized 1:1 to receive either regimen (total dose 360 mg dihydroartemisinin and 2880 mg piperaquine) and followed weekly for up to 6 months. The primary endpoint was malaria recurrence by day 42. Volunteers with vivax infection received primaquine at study discharge with six months follow-up. RESULTS Eighty patients (60 vivax, 15 falciparum, and 5 mixed) were randomized to dihydroartemisinin-piperaquine. Intention-to-treat all-species efficacy at Day 42 was 85% for the two-day regimen (95% CI 69-94) and 90% for the three-day regimen (95% CI 75-97). PCR-adjusted falciparum efficacy was 75% in both groups with nearly half (45%) still parasitemic at Day 3. Plasma piperaquine levels were comparable to prior published reports, but on the day of recrudescence were below measurable in vitro piperaquine IC50 levels in all falciparum treatment failures. CONCLUSIONS In the brief period since introduction of dihydroartemisinin-piperaquine, there is early evidence suggesting declining efficacy relative to previous reports. Parasite IC50 levels in excess of plasma piperaquine levels seen only in treatment failures raises concern for clinically significant piperaquine resistance in Cambodia. These findings warrant improved monitoring of clinical outcomes and follow-up, given few available alternative drugs. TRIAL REGISTRATION ClinicalTrials.gov NCT01280162.
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Affiliation(s)
- Chanthap Lon
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Phnom Penh, Cambodia
| | - Jessica E. Manning
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
- Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
| | - Pattaraporn Vanachayangkul
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Mary So
- Royal Cambodian Armed Forces, Phnom Penh, Cambodia
| | - Darapiseth Sea
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Youry Se
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Phnom Penh, Cambodia
| | - Panita Gosi
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Charlotte Lanteri
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Suwanna Chaorattanakawee
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Sabaithip Sriwichai
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Soklyda Chann
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Phnom Penh, Cambodia
| | - Worachet Kuntawunginn
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Nillawan Buathong
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Samon Nou
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Phnom Penh, Cambodia
| | - Douglas S. Walsh
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Stuart D. Tyner
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Jonathan J. Juliano
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Jessica Lin
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Michele Spring
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Delia Bethell
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
| | - Jaranit Kaewkungwal
- Center of Excellence for Biomedical and Public Health Informatics (BIOPHICS), Mahidol University, Bangkok, Thailand
| | - Douglas Tang
- Fast Track Biologics, Potomac, Maryland, United States of America
| | - Char Meng Chuor
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | | | - David Saunders
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Department of Immunology & Medicine, Bangkok, Thailand
- * E-mail:
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Muhindo MK, Kakuru A, Jagannathan P, Talisuna A, Osilo E, Orukan F, Arinaitwe E, Tappero JW, Kaharuza F, Kamya MR, Dorsey G. Early parasite clearance following artemisinin-based combination therapy among Ugandan children with uncomplicated Plasmodium falciparum malaria. Malar J 2014; 13:32. [PMID: 24468007 PMCID: PMC3909240 DOI: 10.1186/1475-2875-13-32] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 01/21/2014] [Indexed: 11/26/2022] Open
Abstract
Background Artemisinin-based combination therapy (ACT) is widely recommended as first-line therapy for uncomplicated Plasmodium falciparum malaria worldwide. Artemisinin resistance has now been reported in Southeast Asia with a clinical phenotype manifested by slow parasite clearance. Although there are no reliable reports of artemisinin resistance in Africa, there is a need to better understand the dynamics of parasite clearance in African children treated with ACT in order to better detect the emergence of artemisinin resistance. Methods Data from a cohort of Ugandan children four to five years old, enrolled in a longitudinal, randomized, clinical trial comparing two leading ACT, artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP), were analysed. For all episodes of uncomplicated P. falciparum malaria over a 14-month period, daily blood smears were performed for three days following the initiation of therapy. Associations between pre-treatment variables of interest and persistent parasitaemia were estimated using multivariate, generalized, estimating equations with adjustment for repeated measures in the same patient. Results A total of 202 children were included, resulting in 416 episodes of malaria treated with AL and 354 episodes treated with DP. The prevalence of parasitaemia on days 1, 2, and 3 following initiation of therapy was 67.6, 5.6 and 0% in those treated with AL, and 52.2, 5.7 and 0.3% in those treated with DP. Independent risk factors for persistent parasitaemia on day 1 included treatment with AL vs DP (RR = 1.34, 95% CI 1.20-1.50, p < 0.001), having a temperature ≥38.0°C vs < 37.0°C (RR = 1.19, 95% CI 1.05-1.35, p = 0.007) and having a parasite density >20,000/μL vs <4,000/μL (RR = 3.37, 95% CI 2.44-4.49, p < 0.001). Independent risk factors for having persistent parasitaemia on day 2 included elevated temperature, higher parasite density, and being HIV infected. Conclusions Among Ugandan children, parasite clearance following treatment with AL or DP was excellent with only one of 752 patients tested having a positive blood slide three days after initiation of therapy. The type of ACT given, pre-treatment temperature, pre-treatment parasite density and HIV status were associated with differences in persistent parasitaemia, one or two days following therapy. Trial registration Current Controlled Trials Identifier
NCT00527800.
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Affiliation(s)
- Mary K Muhindo
- Infectious Diseases Research Collaboration, Mulago Hospital Campus, PO Box 7475, Kampala, Uganda.
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91
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Phompradit P, Muhamad P, Wisedpanichkij R, Chaijaroenkul W, Na-Bangchang K. Four years' monitoring of in vitro sensitivity and candidate molecular markers of resistance of Plasmodium falciparum to artesunate-mefloquine combination in the Thai-Myanmar border. Malar J 2014; 13:23. [PMID: 24423390 PMCID: PMC3896708 DOI: 10.1186/1475-2875-13-23] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 01/09/2014] [Indexed: 12/02/2022] Open
Abstract
Background The decline in efficacy of artesunate (AS) and mefloquine (MQ) is now the major concern in areas along the Thai-Cambodian and Thai-Myanmar borders. Methods The correlation between polymorphisms of pfatp6, pfcrt, pfmdr1 and pfmrp1 genes and in vitro sensitivity of Plasmodium falciparum isolates to the artemisinin-based combination therapy (ACT) components AS and MQ, including the previously used first-line anti-malarial drugs chloroquine (CQ) and quinine (QN) were investigated in a total of 119 P. falciparum isolates collected from patients with uncomplicated P. falciparum infection during 2006–2009. Results Reduced in vitro parasite sensitivity to AS [median (95% CI) IC50 3.4 (3.1-3.7) nM] was found in 42% of the isolates, whereas resistance to MQ [median (95% CI) IC50 54.1 (46.8-61.4) nM] accounted for 58% of the isolates. Amplification of pfmdr1 gene was strongly associated with a decline in susceptibility of P. falciparum isolates to AS, MQ and QN. Significant difference in IC50 values of AS, MQ and QN was observed among isolates carrying one, two, three, and ≥ four gene copies [median (95% CI) AS IC50: 1.6 (1.3-1.9), 1.8 (1.1-2.5), 2.9 (2.1-3.7) and 3.1 (2.5-3.7) nM, respectively; MQ IC50: 19.2 (15.8-22.6), 37.8 (10.7-64.8), 55.3 (47.7-62.9) and 63.6 (49.2-78.0) nM, respectively; and QN IC50: 183.0 (139.9-226.4), 256.4 (83.7-249.1), 329.5 (206.6-425.5) and 420.0 (475.2-475.6) nM, respectively]. The prevalence of isolates which were resistant to QN was reduced from 21.4% during the period 2006–2007 to 6.3% during the period 2008–2009. Pfmdr1 86Y was found to be associated with increased susceptibility of the parasite to MQ and QN. Pfmdr1 1034C was associated with decreased susceptibility to QN. Pfmrp1 191Y and 1390I were associated with increased susceptibility to CQ and QN, respectively. Conclusion High prevalence of CQ and MQ-resistant P. falciparum isolates was observed during the four-year observation period (2006–2009). AS sensitivity was declined, while QN sensitivity was improved. Pfmdr1 and pfmrp1 appear to be the key genes that modulate multidrug resistance in P. falciparum.
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Affiliation(s)
| | | | | | | | - Kesara Na-Bangchang
- Chulabhorn International College of Medicine, Thammasat University (Rangsit Campus), Patumthani 12121, Thailand.
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92
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Bottieau E, Vekemans M, Van Gompel A. Therapy of vector-borne protozoan infections in nonendemic settings. Expert Rev Anti Infect Ther 2014; 9:583-608. [DOI: 10.1586/eri.11.32] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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93
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Starzengruber P, Fuehrer HP, Ley B, Thriemer K, Swoboda P, Habler VE, Jung M, Graninger W, Khan WA, Haque R, Noedl H. High prevalence of asymptomatic malaria in south-eastern Bangladesh. Malar J 2014; 13:16. [PMID: 24406220 PMCID: PMC3896725 DOI: 10.1186/1475-2875-13-16] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 12/22/2013] [Indexed: 12/23/2022] Open
Abstract
Background The WHO has reported that RDT and microscopy-confirmed malaria cases have declined in recent years. However, it is still unclear if this reflects a real decrease in incidence in Bangladesh, as particularly the hilly and forested areas of the Chittagong Hill Tract (CHT) Districts report more than 80% of all cases and deaths. surveillance and epidemiological data on malaria from the CHT are limited; existing data report Plasmodium falciparum and Plasmodium vivax as the dominant species. Methods A cross-sectional survey was conducted in the District of Bandarban, the southernmost of the three Hill Tracts Districts, to collect district-wide malaria prevalence data from one of the regions with the highest malaria endemicity in Bangladesh. A multistage cluster sampling technique was used to collect blood samples from febrile and afebrile participants and malaria microscopy and standardized nested PCR for diagnosis were performed. Demographic data, vital signs and splenomegaly were recorded. Results Malaria prevalence across all subdistricts in the monsoon season was 30.7% (95% CI: 28.3-33.2) and 14.2% (95% CI: 12.5-16.2) by PCR and microscopy, respectively. Plasmodium falciparum mono-infections accounted for 58.9%, P. vivax mono-infections for 13.6%, Plasmodium malariae for 1.8%, and Plasmodium ovale for 1.4% of all positive cases. In 24.4% of all cases mixed infections were identified by PCR. The proportion of asymptomatic infections among PCR-confirmed cases was 77.0%, oligosymptomatic and symptomatic cases accounted for only 19.8 and 3.2%, respectively. Significantly (p < 0.01) more asymptomatic cases were recorded among participants older than 15 years as compared to younger participants, whereas prevalence and parasite density were significantly (p < 0.01) higher in patients younger than 15 years. Spleen rate and malaria prevalence in two to nine year olds were 18.6 and 34.6%, respectively. No significant difference in malaria prevalence and parasite density was observed between dry and rainy season. Conclusions A large proportion of asymptomatic plasmodial infections was found which likely act as a reservoir of transmission. This has major implications for ongoing malaria control programmes that are based on the treatment of symptomatic patients. These findings highlight the need for new intervention strategies targeting asymptomatic carriers.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Harald Noedl
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, Vienna 1090, Austria.
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94
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Flegg JA, Guérin PJ, Nosten F, Ashley EA, Phyo AP, Dondorp AM, Fairhurst RM, Socheat D, Borrmann S, Björkman A, Mårtensson A, Mayxay M, Newton PN, Bethell D, Se Y, Noedl H, Diakite M, Djimde AA, Hien TT, White NJ, Stepniewska K. Optimal sampling designs for estimation of Plasmodium falciparum clearance rates in patients treated with artemisinin derivatives. Malar J 2013; 12:411. [PMID: 24225303 PMCID: PMC3842737 DOI: 10.1186/1475-2875-12-411] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/28/2013] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The emergence of Plasmodium falciparum resistance to artemisinins in Southeast Asia threatens the control of malaria worldwide. The pharmacodynamic hallmark of artemisinin derivatives is rapid parasite clearance (a short parasite half-life), therefore, the in vivo phenotype of slow clearance defines the reduced susceptibility to the drug. Measurement of parasite counts every six hours during the first three days after treatment have been recommended to measure the parasite clearance half-life, but it remains unclear whether simpler sampling intervals and frequencies might also be sufficient to reliably estimate this parameter. METHODS A total of 2,746 parasite density-time profiles were selected from 13 clinical trials in Thailand, Cambodia, Mali, Vietnam, and Kenya. In these studies, parasite densities were measured every six hours until negative after treatment with an artemisinin derivative (alone or in combination with a partner drug). The WWARN Parasite Clearance Estimator (PCE) tool was used to estimate "reference" half-lives from these six-hourly measurements. The effect of four alternative sampling schedules on half-life estimation was investigated, and compared to the reference half-life (time zero, 6, 12, 24 (A1); zero, 6, 18, 24 (A2); zero, 12, 18, 24 (A3) or zero, 12, 24 (A4) hours and then every 12 hours). Statistical bootstrap methods were used to estimate the sampling distribution of half-lives for parasite populations with different geometric mean half-lives. A simulation study was performed to investigate a suite of 16 potential alternative schedules and half-life estimates generated by each of the schedules were compared to the "true" half-life. The candidate schedules in the simulation study included (among others) six-hourly sampling, schedule A1, schedule A4, and a convenience sampling schedule at six, seven, 24, 25, 48 and 49 hours. RESULTS The median (range) parasite half-life for all clinical studies combined was 3.1 (0.7-12.9) hours. Schedule A1 consistently performed the best, and schedule A4 the worst, both for the individual patient estimates and for the populations generated with the bootstrapping algorithm. In both cases, the differences between the reference and alternative schedules decreased as half-life increased. In the simulation study, 24-hourly sampling performed the worst, and six-hourly sampling the best. The simulation study confirmed that more dense parasite sampling schedules are required to accurately estimate half-life for profiles with short half-life (≤ three hours) and/or low initial parasite density (≤ 10,000 per μL). Among schedules in the simulation study with six or fewer measurements in the first 48 hours, a schedule with measurements at times (time windows) of 0 (0-2), 6 (4-8), 12 (10-14), 24 (22-26), 36 (34-36) and 48 (46-50) hours, or at times 6, 7 (two samples in time window 5-8), 24, 25 (two samples during time 23-26), and 48, 49 (two samples during time 47-50) hours, until negative most accurately estimated the "true" half-life. For a given schedule, continuing sampling after two days had little effect on the estimation of half-life, provided that adequate sampling was performed in the first two days and the half-life was less than three hours. If the measured parasitaemia at two days exceeded 1,000 per μL, continued sampling for at least once a day was needed for accurate half-life estimates. CONCLUSIONS This study has revealed important insights on sampling schedules for accurate and reliable estimation of Plasmodium falciparum half-life following treatment with an artemisinin derivative (alone or in combination with a partner drug). Accurate measurement of short half-lives (rapid clearance) requires more dense sampling schedules (with more than twice daily sampling). A more intensive sampling schedule is, therefore, recommended in locations where P. falciparum susceptibility to artemisinins is not known and the necessary resources are available. Counting parasite density at six hours is important, and less frequent sampling is satisfactory for estimating long parasite half-lives in areas where artemisinin resistance is present.
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Affiliation(s)
- Jennifer A Flegg
- WorldWide Antimalarial Resistance Network (WWARN), University of Oxford, Oxford, UK.
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95
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Gosi P, Lanteri CA, Tyner SD, Se Y, Lon C, Spring M, Char M, Sea D, Sriwichai S, Surasri S, Wongarunkochakorn S, Pidtana K, Walsh DS, Fukuda MM, Manning J, Saunders DL, Bethell D. Evaluation of parasite subpopulations and genetic diversity of the msp1, msp2 and glurp genes during and following artesunate monotherapy treatment of Plasmodium falciparum malaria in Western Cambodia. Malar J 2013; 12:403. [PMID: 24206588 PMCID: PMC3830508 DOI: 10.1186/1475-2875-12-403] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/04/2013] [Indexed: 11/14/2022] Open
Abstract
Background Despite widespread coverage of the emergence of artemisinin resistance, relatively little is known about the parasite populations responsible. The use of PCR genotyping around the highly polymorphic Plasmodium falciparum msp1, msp2 and glurp genes has become well established both to describe variability in alleles within a population of parasites, as well as classify treatment outcome in cases of recurrent disease. The primary objective was to assess the emergence of minority parasite clones during seven days of artesunate (AS) treatment in a location with established artemisinin resistance. An additional objective was to investigate whether the classification of clinical outcomes remained valid when additional genotyping was performed. Methods Blood for parasite genotyping was collected from 143 adult patients presenting with uncomplicated falciparum malaria during a clinical trial of AS monotherapy in Western Cambodia. Nested allelic type-specific amplification of the genes encoding the merozoite surface proteins 1 and 2 (msp1 and msp2) and the glutamate-rich protein (glurp) was performed at baseline, daily during seven days of treatment, and again at failure. Allelic variants were analysed with respect to the size of polymorphisms using Quantity One software to enable identification of polyclonal infections. Results Considerable variation of msp2 alleles but well-conserved msp1 and glurp were identified. At baseline, 31% of infections were polyclonal for one or more genes. Patients with recurrent malaria were significantly more likely to have polyclonal infections than patients without recurrence (seven of nine versus 36 of 127, p = 0.004). Emergence of minority alleles during treatment was detected in only one of twenty-three cases defined as being artemisinin resistant. Moreover, daily genotyping did not alter the final outcome classification in any recurrent cases. Conclusions The parasites responsible for artemisinin-resistant malaria in a clinical trial in Western Cambodia comprise the dominant clones of acute malaria infections rather than minority clones emerging during treatment. Additional genotyping during therapy was not beneficial. Disproportionately high rates of polyclonal infections in cases of recurrence suggest complex infections lead to poor treatment outcomes. Current research objectives should be broadened to include identification and follow-up of recurrent polyclonal infections so as to define their role as potential agents of emerging resistance.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Delia Bethell
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science (AFRIMS), Bangkok, Thailand.
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96
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Na-Bangchang K, Karbwang J. Emerging artemisinin resistance in the border areas of Thailand. Expert Rev Clin Pharmacol 2013; 6:307-22. [PMID: 23656342 DOI: 10.1586/ecp.13.17] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Emergence of artemisinin resistance has been confirmed in Cambodia and the border areas of Thailand, the well-known hotspots of multidrug resistance Plasmodium falciparum. It appears to be spreading to the western border of Thailand along the Thai-Myanmar border, and will probably spread to other endemic areas of the world in the near future. This raises a serious concern on the long-term efficacy of artemisinin-based combination therapies, as these combination therapies currently constitute the last effective and most tolerable treatment for multidrug-resistant Plasmodium falciparum. Attempts have been made by a diverse array of stakeholders to prevent the emergence of new foci of artemisinin resistance, as well as to limit the spread of resistance to the original foci. The success in achieving this goal depends on effective integration of containment and surveillance programs with other malaria control measures, with support from both basic and operational research.
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97
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Li N, Parker DM, Yang Z, Fan Q, Zhou G, Ai G, Duan J, Lee MC, Yan G, Matthews SA, Cui L, Wang Y. Risk factors associated with slide positivity among febrile patients in a conflict zone of north-eastern Myanmar along the China-Myanmar border. Malar J 2013; 12:361. [PMID: 24112638 PMCID: PMC3852943 DOI: 10.1186/1475-2875-12-361] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 09/21/2013] [Indexed: 12/02/2022] Open
Abstract
Background Malaria within the Greater Mekong sub-region is extremely heterogeneous. While China and Thailand have been relatively successful in controlling malaria, Myanmar continues to see high prevalence. Coupled with the recent emergence of artemisinin-resistant malaria along the Thai-Myanmar border, this makes Myanmar an important focus of malaria within the overall region. However, accurate epidemiological data from Myanmar have been lacking, in part because of ongoing and emerging conflicts between the government and various ethnic groups. Here the results are reported from a risk analysis of malaria slide positivity in a conflict zone along the China-Myanmar border. Methods Surveys were conducted in 13 clinics and hospitals around Laiza City, Myanmar between April 2011 and October 2012. Demographic, occupational and educational information, as well as malaria infection history, were collected. Logistic models were used to assess risk factors for slide positivity. Results Age patterns in Plasmodium vivax infections were younger than those with Plasmodium falciparum. Furthermore, males were more likely than females to have falciparum infections. Patients who reported having been infected with malaria during the previous year were much more likely to have a current vivax infection. During the second year of the study, falciparum infections among soldiers increased signficiantly. Conclusions These results fill some knowledge gaps with regard to risk factors associated with malaria slide positivity in this conflict region of north-eastern Myanmar. Since epidemiological studies in this region have been rare or non-existent, studies such as the current are crucial for understanding the dynamic nature of malaria in this extremely heterogeneous epidemiological landscape.
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Affiliation(s)
- Nana Li
- Department of Tropical Disease, Institute of Tropical Medicine, Third Military Medical University, Chongqing, China.
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Plasmodium falciparum Polymorphisms associated with ex vivo drug susceptibility and clinical effectiveness of artemisinin-based combination therapies in Benin. Antimicrob Agents Chemother 2013; 58:1-10. [PMID: 24100489 DOI: 10.1128/aac.01790-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Artemisinin-based combination therapies (ACTs) are the main option to treat malaria, and their efficacy and susceptibility must be closely monitored to avoid resistance. We assessed the association of Plasmodium falciparum polymorphisms and ex vivo drug susceptibility with clinical effectiveness. Patients enrolled in an effectiveness trial comparing artemether-lumefantrine (n = 96), fixed-dose artesunate-amodiaquine (n = 96), and sulfadoxine-pyrimethamine (n = 48) for the treatment of uncomplicated malaria 2007 in Benin were assessed. pfcrt, pfmdr1, pfmrp1, pfdhfr, and pfdhps polymorphisms were analyzed pretreatment and in recurrent infections. Drug susceptibility was determined in fresh baseline isolates by Plasmodium lactate dehydrogenase enzyme-linked immunosorbent assay (ELISA). A majority had 50% inhibitory concentration (IC50) estimates (the concentration required for 50% growth inhibition) lower than those of the 3D7 reference clone for desethylamodiaquine, lumefantrine, mefloquine, and quinine and was considered to be susceptible, while dihydroartemisinin and pyrimethamine IC50s were higher. No association was found between susceptibility to the ACT compounds and treatment outcome. Selection was observed for the pfmdr1 N86 allele in artemether-lumefantrine recrudescences (recurring infections) (4/7 [57.1%] versus 36/195 [18.5%]), and of the opposite allele, 86Y, in artesunate-amodiaquine reinfections (new infections) (20/22 [90.9%] versus 137/195 [70.3%]) compared to baseline infections. The importance of pfmdr1 N86 in lumefantrine tolerance was emphasized by its association with elevated lumefantrine IC50s. Genetic linkage between N86 and Y184 was observed, which together with the low frequency of 1246Y may explain regional differences in selection of pfmdr1 loci. Selection of opposite alleles in artemether-lumefantrine and artesunate-amodiaquine recurrent infections supports the strategy of multiple first-line treatment. Surveillance based on clinical, ex vivo, molecular, and pharmacological data is warranted.
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Synthesis, in vitro antiplasmodial and antiproliferative activities of a series of quinoline–ferrocene hybrids. Med Chem Res 2013. [DOI: 10.1007/s00044-013-0748-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Aborah S, Akweongo P, Adjuik M, Atinga RA, Welaga P, Adongo PB. The use of non-prescribed anti-malarial drugs for the treatment of malaria in the Bolgatanga municipality, northern Ghana. Malar J 2013; 12:266. [PMID: 23902654 PMCID: PMC3735414 DOI: 10.1186/1475-2875-12-266] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 07/29/2013] [Indexed: 11/13/2022] Open
Abstract
Background The use of non-prescribed anti-malarial drugs can lead to treatment failure and development of drug-resistant parasites. This study investigated the use of non-prescribed anti-malarial drugs for the treatment of malaria in the Bolgatanga Municipality of northern Ghana. Methods This was a cross-sectional survey of a random sample of 392 adults and children with episodes of malaria in the last four weeks prior to the study. Results Majority of survey respondents 96.9% (380) knew the symptoms of malaria, 75% (294) knew the causes of malaria and 93.1% (365) were aware of mode of transmission of malaria. The use of non-prescribed anti-malarial drugs was 16.8% (95% CI: 13.3-21.0) among the respondents. About 56% (95% CI: 43.3-68.3) of the respondents who took non-prescribed anti-malaria drugs took non-artemisinin-based combination therapy (chloroquine, artemether, amodiaquine and sulphadoxine-pyrimethamine). Respondents above five years of age were more likely to use non-prescribed anti-malarial drugs than those below five years of age [P < 0.001]; respondents who knew the right source of malaria treatment were less likely to use non-prescribed anti-malarial drugs than those who did not [P = 0.002]. Respondents using non-prescribed anti-malarials were influenced by people around them who used non-prescribed anti-malarials. Thus, these respondents were more likely to use non-prescribed anti-malarials than those who were not influenced [P = 0.004]. Conclusions Respondents’ knowledge of malaria treatment and the influence of people using non-prescribed anti-malarials are factors affecting use of non-prescribed anti-malarials. The study concludes that there is high use of non-prescribed anti-malarial drugs in the municipality and most of the non-prescribed anti-malarias were non-artemisinin-based combination therapy. The study recommends education of the general public and chemical sellers to reduce the use of non-prescribe anti-malaria drugs.
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Affiliation(s)
- Samuel Aborah
- Ghana Health Service, Bolgatanga Regional Hospital, Bolgatanga, Ghana
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