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Thita T, Jadsri P, Thamkhantho J, Ruang-Areerate T, Suwandittakul N, Sitthichot N, Mahotorn K, Tan-Ariya P, Mungthin M. Phenotypic and genotypic characterization of Thai isolates of Plasmodium falciparum after an artemisinin resistance containment project. Malar J 2018; 17:197. [PMID: 29764451 PMCID: PMC5952644 DOI: 10.1186/s12936-018-2347-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/07/2018] [Indexed: 11/28/2022] Open
Abstract
Background In Thailand, artemisinin-based combination therapy (ACT) has been used to treat uncomplicated falciparum malaria since 1995. Unfortunately, artemisinin resistance has been reported from Thailand and other Southeast Asian countries since 2003. Malarone®, a combination of atovaquone–proguanil (ATQ–PG), has been used to cease artemisinin pressure in some areas along Thai–Cambodia border, as part of an artemisinin resistance containment project since 2009. This study aimed to determine genotypes and phenotypes of Plasmodium falciparum isolates collected from the Thai–Cambodia border after the artemisinin resistance containment project compared with those collected before. Results One hundred and nine of P. falciparum isolates collected from Thai–Cambodia border from Chanthaburi and Trat provinces during 1988–2016 were used in this study. Of these, 58 isolates were collected after the containment. These parasite isolates were characterized for in vitro antimalarial sensitivities including chloroquine (CQ), quinine (QN), mefloquine (MQ), piperaquine (PPQ), artesunate (AS), dihydroartemisinin (DHA), ATQ and PG and genetic markers for drug resistance including the Kelch13 (k13), Plasmodium falciparum chloroquine resistance transporter (pfcrt), P. falciparum multidrug resistance 1 (pfmdr1) and cytochrome b (cytb) genes. Mean CQ, QN, MQ, PPQ and AS IC50s of the parasite isolates collected from 2009 to 2016 exhibited significantly higher than those of parasites collected before 2009. Approximately 57% exhibited in vitro MQ resistance. Approximately 94% of the isolates collected from 2009 to 2016 contained the pfmdr1 184F allele. Mutations of the k13 gene were detected in approximately 90% of the parasites collected from 2009 to 2016 which were significantly higher than the parasite isolates collected before. No ATQ-resistant genotype and phenotype of P. falciparum were found among the isolates collected after the containment project. Conclusions Although the containment project had been implemented in this area, the expansion of artemisinin-resistant parasites did not decline. In addition, reduced sensitivity of the partner drugs of ACT including MQ and PPQ were identified.
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Affiliation(s)
- Thunyapit Thita
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Pimrat Jadsri
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Jarupatr Thamkhantho
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Toon Ruang-Areerate
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok, Thailand
| | | | - Naruemon Sitthichot
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok, Thailand
| | - Kittiya Mahotorn
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Peerapan Tan-Ariya
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Mathirut Mungthin
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok, Thailand.
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52
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Bopp S, Magistrado P, Wong W, Schaffner SF, Mukherjee A, Lim P, Dhorda M, Amaratunga C, Woodrow CJ, Ashley EA, White NJ, Dondorp AM, Fairhurst RM, Ariey F, Menard D, Wirth DF, Volkman SK. Plasmepsin II-III copy number accounts for bimodal piperaquine resistance among Cambodian Plasmodium falciparum. Nat Commun 2018; 9:1769. [PMID: 29720620 PMCID: PMC5931971 DOI: 10.1038/s41467-018-04104-z] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 03/30/2018] [Indexed: 12/30/2022] Open
Abstract
Multidrug resistant Plasmodium falciparum in Southeast Asia endangers regional malaria elimination and threatens to spread to other malaria endemic areas. Understanding mechanisms of piperaquine (PPQ) resistance is crucial for tracking its emergence and spread, and to develop effective strategies for overcoming it. Here we analyze a mechanism of PPQ resistance in Cambodian parasites. Isolates exhibit a bimodal dose-response curve when exposed to PPQ, with the area under the curve quantifying their survival in vitro. Increased copy number for plasmepsin II and plasmepsin III appears to explain enhanced survival when exposed to PPQ in most, but not all cases. A panel of isogenic subclones reinforces the importance of plasmepsin II-III copy number to enhanced PPQ survival. We conjecture that factors producing increased parasite survival under PPQ exposure in vitro may drive clinical PPQ failures in the field.
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Affiliation(s)
- Selina Bopp
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | | | - Wesley Wong
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Stephen F Schaffner
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Angana Mukherjee
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Pharath Lim
- National Institutes of Health, Rockville, MD, 20892, USA
| | - Mehul Dhorda
- Worldwide Antimalarial Resistance Network, Bangkok, 10400, Thailand
- Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, 10400, Thailand
- Myanmar-Oxford Clinical Research Unit, Yangon, Myanmar
| | | | - Charles J Woodrow
- Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, 10400, Thailand
| | - Elizabeth A Ashley
- Myanmar-Oxford Clinical Research Unit, Yangon, Myanmar
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
| | | | - Frederic Ariey
- Institut Cochin, INSERM U:1016, Parasitology-Mycology Unit, Cochin Hospital Paris Descartes University, Paris, 75014, France
| | - Didier Menard
- Biology of Host-Parasite Interactions Unit, Institut Pasteur, Paris, 75015, France
- CNRS, ERL 9195, Paris, 75794, France
- INSERM, Unit U1201, Paris, 75015, France
| | - Dyann F Wirth
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Sarah K Volkman
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
- The Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
- Simmons College, Boston, MA, 02115, USA.
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53
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Ouji M, Augereau JM, Paloque L, Benoit-Vical F. Plasmodium falciparum resistance to artemisinin-based combination therapies: A sword of Damocles in the path toward malaria elimination. Parasite 2018; 25:24. [PMID: 29676250 PMCID: PMC5909375 DOI: 10.1051/parasite/2018021] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 03/15/2018] [Indexed: 01/28/2023] Open
Abstract
The use of artemisinin-based combination therapies (ACTs), which combine an artemisinin derivative with a partner drug, in the treatment of uncomplicated malaria has largely been responsible for the significant reduction in malaria-related mortality in tropical and subtropical regions. ACTs have also played a significant role in the 18% decline in the incidence of malaria cases from 2010 to 2016. However, this progress is seriously threatened by the reduced clinical efficacy of artemisinins, which is characterised by delayed parasitic clearance and a high rate of recrudescence, as reported in 2008 in Western Cambodia. Resistance to artemisinins has already spread to several countries in Southeast Asia. Furthermore, resistance to partner drugs has been shown in some instances to be facilitated by pre-existing decreased susceptibility to the artemisinin component of the ACT. A major concern is not only the spread of these multidrug-resistant parasites to the rest of Asia but also their possible appearance in Sub-Saharan Africa, the continent most affected by malaria, as has been the case in the past with parasite resistance to other antimalarial treatments. It is therefore essential to understand the acquisition of resistance to artemisinins by Plasmodium falciparum to adapt malaria treatment policies and to propose new therapeutic solutions.
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Affiliation(s)
- Manel Ouji
- LCC (Laboratoire de Chimie de Coordination du CNRS),
BP 44099, 205 Route de Narbonne,
31077
Toulouse cedex 4 France
- Université de Toulouse; UPS, INPT; LCC;
F-31077
Toulouse France
| | - Jean-Michel Augereau
- LCC (Laboratoire de Chimie de Coordination du CNRS),
BP 44099, 205 Route de Narbonne,
31077
Toulouse cedex 4 France
- Université de Toulouse; UPS, INPT; LCC;
F-31077
Toulouse France
| | - Lucie Paloque
- LCC (Laboratoire de Chimie de Coordination du CNRS),
BP 44099, 205 Route de Narbonne,
31077
Toulouse cedex 4 France
- Université de Toulouse; UPS, INPT; LCC;
F-31077
Toulouse France
| | - Françoise Benoit-Vical
- LCC (Laboratoire de Chimie de Coordination du CNRS),
BP 44099, 205 Route de Narbonne,
31077
Toulouse cedex 4 France
- Université de Toulouse; UPS, INPT; LCC;
F-31077
Toulouse France
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54
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Huijben S, Paaijmans KP. Putting evolution in elimination: Winning our ongoing battle with evolving malaria mosquitoes and parasites. Evol Appl 2018; 11:415-430. [PMID: 29636796 PMCID: PMC5891050 DOI: 10.1111/eva.12530] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/01/2017] [Indexed: 12/17/2022] Open
Abstract
Since 2000, the world has made significant progress in reducing malaria morbidity and mortality, and several countries in Africa, South America and South-East Asia are working hard to eliminate the disease. These elimination efforts continue to rely heavily on antimalarial drugs and insecticide-based interventions, which remain the cornerstones of malaria treatment and prevention. However, resistance has emerged against nearly every antimalarial drug and insecticide that is available. In this review we discuss the evolutionary consequences of the way we currently implement antimalarial interventions, which is leading to resistance and may ultimately lead to control failure, but also how evolutionary principles can be applied to extend the lifespan of current and novel interventions. A greater understanding of the general evolutionary principles that are at the core of emerging resistance is urgently needed if we are to develop improved resistance management strategies with the ultimate goal to achieve a malaria-free world.
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Affiliation(s)
- Silvie Huijben
- ISGlobalBarcelona Ctr. Int. Health Res. (CRESIB)Hospital Clínic ‐ Universitat de BarcelonaBarcelonaSpain
| | - Krijn P. Paaijmans
- ISGlobalBarcelona Ctr. Int. Health Res. (CRESIB)Hospital Clínic ‐ Universitat de BarcelonaBarcelonaSpain
- Centro de Investigação em Saúde de ManhiçaMaputoMozambique
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55
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Poespoprodjo JR, Kenangalem E, Wafom J, Chandrawati F, Puspitasari AM, Ley B, Trianty L, Korten Z, Surya A, Syafruddin D, Anstey NM, Marfurt J, Noviyanti R, Price RN. Therapeutic Response to Dihydroartemisinin-Piperaquine for P. falciparum and P. vivax Nine Years after Its Introduction in Southern Papua, Indonesia. Am J Trop Med Hyg 2018; 98:677-682. [PMID: 29345221 PMCID: PMC5850981 DOI: 10.4269/ajtmh.17-0662] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Dihydroartemisinin-piperaquine (DHP) has been the first-line treatment of uncomplicated malaria due to both Plasmodium falciparum and Plasmodium vivax infections in Papua, Indonesia, since March 2006. The efficacy of DHP was reassessed to determine whether there had been any decline following almost a decade of its extensive use. An open-label drug efficacy study of DHP for uncomplicated P. falciparum and P. vivax malaria was carried out between March 2015 and April 2016 in Timika, Papua, Indonesia. Patients with uncomplicated malaria were administered supervised DHP tablets once daily for 3 days. Clinical and laboratory data were collected daily until parasite clearance and then weekly for 6 weeks. Molecular analysis was undertaken for all patients with recurrent parasitemia. A total of 129 study patients were enrolled in the study. At day 42, the polymerase chain reaction-adjusted efficacy was 97.7% (95% confidence intervals [CI]: 87.4-99.9) in the 61 patients with P. falciparum malaria, and 98.2% [95% CI: 90.3-100] in the 56 patients with P. vivax malaria. By day 2, 98% (56/57) of patients with P. falciparum and 96.9% (63/65) of those with P. vivax had cleared their peripheral parasitemia; none of the patients were still parasitaemic on day 3. Molecular analysis of P. falciparum parasites showed that none (0/61) had K13 mutations associated previously with artemisinin resistance or increased copy number of plasmepsin 2-3 (0/61). In the absence of artemisinin resistance, DHP has retained high efficacy for the treatment of uncomplicated malaria despite extensive drug pressure over a 9-year period.
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Affiliation(s)
- Jeanne Rini Poespoprodjo
- Mimika District Hospital, Timika, Indonesia;,Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Indonesia;,Paediatric Research Office, Department of Child Health, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, Indonesia;,Address correspondence to Jeanne Rini Poespoprodjo, Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Indonesia. E-mail:
| | - Enny Kenangalem
- Mimika District Hospital, Timika, Indonesia;,Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Indonesia
| | - Johny Wafom
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Indonesia
| | - Freis Chandrawati
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Indonesia
| | | | - Benedikt Ley
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Leily Trianty
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Zoé Korten
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Asik Surya
- Indonesian Ministry of Health, National Malaria Control Program, Jakarta, Indonesia
| | - Din Syafruddin
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Jutta Marfurt
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | | | - 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
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56
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Amato R, Pearson RD, Almagro-Garcia J, Amaratunga C, Lim P, Suon S, Sreng S, Drury E, Stalker J, Miotto O, Fairhurst RM, Kwiatkowski DP. Origins of the current outbreak of multidrug-resistant malaria in southeast Asia: a retrospective genetic study. THE LANCET. INFECTIOUS DISEASES 2018; 18:337-345. [PMID: 29398391 PMCID: PMC5835763 DOI: 10.1016/s1473-3099(18)30068-9] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/02/2017] [Accepted: 12/11/2017] [Indexed: 10/25/2022]
Abstract
BACKGROUND Antimalarial resistance is rapidly spreading across parts of southeast Asia where dihydroartemisinin-piperaquine is used as first-line treatment for Plasmodium falciparum malaria. The first published reports about resistance to antimalarial drugs came from western Cambodia in 2013. Here, we analyse genetic changes in the P falciparum population of western Cambodia in the 6 years before those reports. METHODS We analysed genome sequence data on 1492 P falciparum samples from 11 locations across southeast Asia, including 464 samples collected in western Cambodia between 2007 and 2013. Different epidemiological origins of resistance were identified by haplotypic analysis of the kelch13 artemisinin resistance locus and the plasmepsin 2-3 piperaquine resistance locus. FINDINGS We identified more than 30 independent origins of artemisinin resistance, of which the KEL1 lineage accounted for 140 (91%) of 154 parasites resistant to dihydroartemisinin-piperaquine. In 2008, KEL1 combined with PLA1, the major lineage associated with piperaquine resistance. By 2013, the KEL1/PLA1 co-lineage had reached a frequency of 63% (24/38) in western Cambodia and had spread to northern Cambodia. INTERPRETATION The KEL1/PLA1 co-lineage emerged in the same year that dihydroartemisinin-piperaquine became the first-line antimalarial drug in western Cambodia and spread rapidly thereafter, displacing other artemisinin-resistant parasite lineages. These findings have important implications for management of the global health risk associated with the current outbreak of multidrug-resistant malaria in southeast Asia. FUNDING Wellcome Trust, Bill & Melinda Gates Foundation, Medical Research Council, UK Department for International Development, and the Intramural Research Program of the National Institute of Allergy and Infectious Diseases.
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Affiliation(s)
- Roberto Amato
- Wellcome Sanger Institute, Hinxton, UK; MRC Centre for Genomics and Global Health, Big Data Institute, Oxford University, Oxford, UK.
| | - Richard D Pearson
- Wellcome Sanger Institute, Hinxton, UK; MRC Centre for Genomics and Global Health, Big Data Institute, Oxford University, Oxford, UK
| | - Jacob Almagro-Garcia
- Wellcome Sanger Institute, Hinxton, UK; MRC Centre for Genomics and Global Health, Big Data Institute, Oxford University, Oxford, UK
| | - Chanaki Amaratunga
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Pharath Lim
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA; National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Seila Suon
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Sokunthea Sreng
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | | | | | - Olivo Miotto
- Wellcome Sanger Institute, Hinxton, UK; MRC Centre for Genomics and Global Health, Big Data Institute, Oxford University, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Rick M Fairhurst
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Dominic P Kwiatkowski
- Wellcome Sanger Institute, Hinxton, UK; MRC Centre for Genomics and Global Health, Big Data Institute, Oxford University, Oxford, UK.
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57
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Niaré K, Paloque L, Ménard S, Tor P, Ramadani AP, Augereau JM, Dara A, Berry A, Benoit-Vical F, Doumbo OK. Multiple Phenotypic and Genotypic Artemisinin Sensitivity Evaluation of Malian Plasmodium falciparum Isolates. Am J Trop Med Hyg 2018; 98:1123-1131. [PMID: 29436338 DOI: 10.4269/ajtmh.17-0798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We assessed the ex vivo/in vitro sensitivity of 54 Malian Plasmodium falciparum isolates to artemisinin for the monitoring of drug resistance in this area. The artemisinin sensitivity of parasites was evaluated using 1) the ex vivo and in vitro parasite recrudescence detection after treatment of the ring stage with 1-200 nM artemisinin for 48 hours and 2) the in vitro parasite recrudescence kinetics assay over 7 days after 6-hour treatment of the ring stage with 700 nM dihydroartemisinin (DHA). In addition, as recommended by the World Health Organization for artemisinin resistance characterization, the ring-stage survival assay (RSA0-3 h) was performed and the parasite isolates were sequenced at the kelch 13 propeller locus. No clinical and molecular evidence of artemisinin resistance was observed. However, these isolates present different phenotypic profiles in response to artemisinin treatments. Despite all RSA0-3 h values less than 1.5%, six out of 46 (13.0%) isolates tested ex vivo and four out of six (66.7%) isolates tested in vitro were able to multiply after 48-hour treatments with 100 nM artemisinin. Moreover, five out of eight isolates tested showed faster parasite recovery after DHA treatment in kinetic assays. The presence of such phenotypes needs to be taken into account in the assessment of the efficacy of artemisinins in Mali. The assays presented here appear as valuable tools for the monitoring of artemisinin sensitivity in the field and thus could help to evaluate the risk of emergence of artemisinin resistance in Africa.
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Affiliation(s)
- Karamoko Niaré
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Lucie Paloque
- Laboratoire de Chimie de Coordination du CNRS, CentreNationale de la Recherche Scientifique, Université de Toulouse, UPS, INPT, Toulouse, France
| | - Sandie Ménard
- Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, Toulouse, France
| | - Pety Tor
- Laboratoire de Chimie de Coordination du CNRS, CentreNationale de la Recherche Scientifique, Université de Toulouse, UPS, INPT, Toulouse, France
| | - Arba P Ramadani
- Laboratoire de Chimie de Coordination du CNRS, CentreNationale de la Recherche Scientifique, Université de Toulouse, UPS, INPT, Toulouse, France
| | - Jean-Michel Augereau
- Laboratoire de Chimie de Coordination du CNRS, CentreNationale de la Recherche Scientifique, Université de Toulouse, UPS, INPT, Toulouse, France
| | - Antoine Dara
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, Maryland.,Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Antoine Berry
- Service de Parasitologie-Mycologie, Centre Hospitalier et Universitaire de Toulouse, Toulouse, France.,Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, Toulouse, France
| | - Françoise Benoit-Vical
- Laboratoire de Chimie de Coordination du CNRS, CentreNationale de la Recherche Scientifique, Université de Toulouse, UPS, INPT, Toulouse, France
| | - Ogobara K Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
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58
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Chaorattanakawee S, Lon C, Chann S, Thay KH, Kong N, You Y, Sundrakes S, Thamnurak C, Chattrakarn S, Praditpol C, Yingyuen K, Wojnarski M, Huy R, Spring MD, Walsh DS, Patel JC, Lin J, Juliano JJ, Lanteri CA, Saunders DL. Measuring ex vivo drug susceptibility in Plasmodium vivax isolates from Cambodia. Malar J 2017; 16:392. [PMID: 28964258 PMCID: PMC5622433 DOI: 10.1186/s12936-017-2034-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 09/19/2017] [Indexed: 12/24/2022] Open
Abstract
Background While intensive Plasmodium falciparum multidrug resistance surveillance continues in Cambodia, relatively little is known about Plasmodium vivax drug resistance in Cambodia or elsewhere. To investigate P. vivax anti-malarial susceptibility in Cambodia, 76 fresh P. vivax isolates collected from Oddar Meanchey (northern Cambodia) in 2013–2015 were assessed for ex vivo drug susceptibility using the microscopy-based schizont maturation test (SMT) and a Plasmodium pan-species lactate dehydrogenase (pLDH) ELISA. P. vivax multidrug resistance gene 1 (pvmdr1) mutations, and copy number were analysed in a subset of isolates. Results Ex vivo testing was interpretable in 80% of isolates using the pLDH-ELISA, but only 25% with the SMT. Plasmodium vivax drug susceptibility by pLDH-ELISA was directly compared with 58 P. falciparum isolates collected from the same locations in 2013–4, tested by histidine-rich protein-2 ELISA. Median pLDH-ELISA IC50 of P. vivax isolates was significantly lower for dihydroartemisinin (3.4 vs 6.3 nM), artesunate (3.2 vs 5.7 nM), and chloroquine (22.1 vs 103.8 nM) than P. falciparum but higher for mefloquine (92 vs 66 nM). There were not significant differences for lumefantrine or doxycycline. Both P. vivax and P. falciparum had comparable median piperaquine IC50 (106.5 vs 123.8 nM), but some P. falciparum isolates were able to grow in much higher concentrations above the normal standard range used, attaining up to 100-fold greater IC50s than P. vivax. A high percentage of P. vivax isolates had pvmdr1 Y976F (78%) and F1076L (83%) mutations but none had pvmdr1 amplification. Conclusion The findings of high P. vivax IC50 to mefloquine and piperaquine, but not chloroquine, suggest significant drug pressure from drugs used to treat multidrug resistant P. falciparum in Cambodia. Plasmodium vivax isolates are frequently exposed to mefloquine and piperaquine due to mixed infections and the long elimination half-life of these drugs. Difficulty distinguishing infection due to relapsing hypnozoites versus blood-stage recrudescence complicates clinical detection of P. vivax resistance, while well-validated molecular markers of chloroquine resistance remain elusive. The pLDH assay may be a useful adjunctive tool for monitoring for emerging drug resistance, though more thorough validation is needed. Given high grade clinical chloroquine resistance observed recently in neighbouring countries, low chloroquine IC50 values seen here should not be interpreted as susceptibility in the absence of clinical data. Incorporating pLDH monitoring with therapeutic efficacy studies for individuals with P. vivax will help to further validate this field-expedient method. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-2034-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Suwanna Chaorattanakawee
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand. .,Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
| | - Chanthap Lon
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Soklyda Chann
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Kheang Heng Thay
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Nareth Kong
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Yom You
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Siratchana Sundrakes
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Chatchadaporn Thamnurak
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Sorayut Chattrakarn
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Chantida Praditpol
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Kritsanai Yingyuen
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Mariusz Wojnarski
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Rekol Huy
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Michele D Spring
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Douglas S Walsh
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - Jaymin C Patel
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Jessica Lin
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Charlotte A Lanteri
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand
| | - David L Saunders
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Science, Bangkok, Thailand.,US Army Medical Materiel Development Activity, Fort Detrick, Frederick, MD, USA
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Okami S, Kohtake N. Spatiotemporal Modeling for Fine-Scale Maps of Regional Malaria Endemicity and Its Implications for Transitional Complexities in a Routine Surveillance Network in Western Cambodia. Front Public Health 2017; 5:262. [PMID: 29034229 PMCID: PMC5627027 DOI: 10.3389/fpubh.2017.00262] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 09/13/2017] [Indexed: 11/24/2022] Open
Abstract
Due to the associated and substantial efforts of many stakeholders involved in malaria containment, the disease burden of malaria has dramatically decreased in many malaria-endemic countries in recent years. Some decades after the past efforts of the global malaria eradication program, malaria elimination has again featured on the global health agenda. While risk distribution modeling and a mapping approach are effective tools to assist with the efficient allocation of limited health-care resources, these methods need some adjustment and reexamination in accordance with changes occurring in relation to malaria elimination. Limited available data, fine-scale data inaccessibility (for example, household or individual case data), and the lack of reliable data due to inefficiencies within the routine surveillance system, make it difficult to create reliable risk maps for decision-makers or health-care practitioners in the field. Furthermore, the risk of malaria may dynamically change due to various factors such as the progress of containment interventions and environmental changes. To address the complex and dynamic nature of situations in low-to-moderate malaria transmission settings, we built a spatiotemporal model of a standardized morbidity ratio (SMR) of malaria incidence, calculated through annual parasite incidence, using routinely reported surveillance data in combination with environmental indices such as remote sensing data, and the non-environmental regional containment status, to create fine-scale risk maps. A hierarchical Bayesian frame was employed to fit the transitioning malaria risk data onto the map. The model was set to estimate the SMRs of every study location at specific time intervals within its uncertainty range. Using the spatial interpolation of estimated SMRs at village level, we created fine-scale maps of two provinces in western Cambodia at specific time intervals. The maps presented different patterns of malaria risk distribution at specific time intervals. Moreover, the visualized weights estimated using the risk model, and the structure of the routine surveillance network, represent the transitional complexities emerging from ever-changing regional endemic situations.
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Affiliation(s)
- Suguru Okami
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
| | - Naohiko Kohtake
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
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60
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Kheang ST, Sovannaroth S, Ek S, Chy S, Chhun P, Mao S, Nguon S, Lek DS, Menard D, Kak N. Prevalence of K13 mutation and Day-3 positive parasitaemia in artemisinin-resistant malaria endemic area of Cambodia: a cross-sectional study. Malar J 2017; 16:372. [PMID: 28903755 PMCID: PMC5598042 DOI: 10.1186/s12936-017-2024-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 09/07/2017] [Indexed: 11/29/2022] Open
Abstract
Background The presence of artemisinin-resistant malaria parasites was confirmed in western Cambodia in 2009. In 2013, mutations in the propeller domain of the kelch protein K13 was found to be associated with artemisinin resistance. A cross-sectional study was conducted to determine the prevalence of Day-3 parasitaemia, estimate the frequency of k13 molecular marker and assess their relationship in the context of operational research. Methods Blood smears and filter paper blood spots were collected from febrile patients in Kravanh District, Pursat Province. The blood smears were examined by microscopy, and blood spots by a k13 mutation assay. Results Data from 92 patients were analysed. Only one was positive for Day-3 parasitaemia. Results of the k13 assay were interpretable for 76 of the 92 samples. The findings were: wild type: 9 (12%), C580Y: 64 (84%), Y493H: 3 (4%). Therefore, despite the high prevalence of k13 mutants (67/76: 88%), only 1 of the 92 patients remained blood smear positive for Plasmodium falciparum on Day-3. Conclusions These preliminary findings suggest good potency of artemisinin despite the dominance of k13 mutation in Kravanh, but the result is not necessarily representative of the western part of Cambodia. Further investigation should be made to determine if k13 marker remains useful as a tool for tracking artemisinin resistance and predicting the trend of the efficacy of artemisinin combination therapy once the mutant alleles have been well established in the population.
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Affiliation(s)
- Soy Ty Kheang
- PMI/USAID Control and Prevention of Malaria (CAP-Malaria)/Cambodia Malaria Elimination Project (CMEP) projects, University Research Co., LLC, Phnow Penh, Cambodia.
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnow Penh, Cambodia
| | - Sovann Ek
- PMI/USAID Control and Prevention of Malaria (CAP-Malaria)/Cambodia Malaria Elimination Project (CMEP) projects, University Research Co., LLC, Phnow Penh, Cambodia
| | - Say Chy
- PMI/USAID Control and Prevention of Malaria (CAP-Malaria)/Cambodia Malaria Elimination Project (CMEP) projects, University Research Co., LLC, Phnow Penh, Cambodia
| | - Phally Chhun
- PMI/USAID Control and Prevention of Malaria (CAP-Malaria)/Cambodia Malaria Elimination Project (CMEP) projects, University Research Co., LLC, Phnow Penh, Cambodia
| | - Sokkieng Mao
- PMI/USAID Control and Prevention of Malaria (CAP-Malaria)/Cambodia Malaria Elimination Project (CMEP) projects, University Research Co., LLC, Phnow Penh, Cambodia
| | - Sokomar Nguon
- PMI/USAID Control and Prevention of Malaria (CAP-Malaria)/Cambodia Malaria Elimination Project (CMEP) projects, University Research Co., LLC, Phnow Penh, Cambodia
| | - Dy Soley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnow Penh, Cambodia
| | - Didier Menard
- Pasteur Institute in Cambodia (IPC), Phnow Penh, Cambodia
| | - Neeraj Kak
- PMI/USAID Control and Prevention of Malaria (CAP-Malaria)/Cambodia Malaria Elimination Project (CMEP) projects, University Research Co., LLC, Phnow Penh, Cambodia
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61
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Canavati SE, Quintero CE, Haller B, Lek D, Yok S, Richards JS, Whittaker MA. Maximizing research study effectiveness in malaria elimination settings: a mixed methods study to capture the experiences of field-based staff. Malar J 2017; 16:362. [PMID: 28893264 PMCID: PMC5594431 DOI: 10.1186/s12936-017-2016-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 09/06/2017] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND In a drug-resistant, malaria elimination setting like Western Cambodia, field research is essential for the development of novel anti-malarial regimens and the public health solutions necessary to monitor the spread of resistance and eliminate infection. Such field studies often face a variety of similar implementation challenges, but these are rarely captured in a systematic way or used to optimize future study designs that might overcome similar challenges. Field-based research staff often have extensive experience and can provide valuable insight regarding these issues, but their perspectives and experiences are rarely documented and seldom integrated into future research protocols. This mixed-methods analysis sought to gain an understanding of the daily challenges encountered by research field staff in the artemisinin-resistant, malaria elimination setting of Western Cambodia. In doing so, this study seeks to understand how the experiences and opinions of field staff can be captured, and used to inform future study designs. METHODS Twenty-two reports from six field-based malaria studies conducted in Western Cambodia were reviewed using content analysis to identify challenges to conducting the research. Informal Interviews, Focus Group Discussions and In-depth Interviews were also conducted among field research staff. Thematic analysis of the data was undertaken using Nvivo 9® software. Triangulation and critical case analysis was also used. RESULTS There was a lack of formalized avenues through which field workers could report challenges experienced when conducting the malaria studies. Field research staff faced significant logistical barriers to participant recruitment and data collection, including a lack of available transportation to cover long distances, and the fact that mobile and migrant populations (MMPs) are usually excluded from studies because of challenges in follow-up. Cultural barriers to communication also hindered participant recruitment and created unexpected delays. Field staff often paid a physical, emotional and financial cost, going beyond their duty in order to keep the study running. CONCLUSIONS Formal monthly reports filled out by field study staff could be a key tool for capturing field study staff experiences effectively, but require specific report fields to encourage staff to outline their challenges and to propose potential solutions. Forging strong bonds with communities and their leaders may improve communication, and decrease barriers to participant recruitment. Study designs that make it feasible for MMPs to participate should be pursued; in addition to increasing the potential participant pool, this will ensure that the most malaria-endemic demographic is taken into account in research studies. Overlaps between clinical care and research create ethical dilemmas for study staff, a fact that warrants careful consideration. Lessons learned from study field staff should be used to create a set of locally-relevant recommendations to inform future study designs.
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Affiliation(s)
- Sara E. Canavati
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- Vysnova Partners Inc., Washington, DC USA
| | - Cesia E. Quintero
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | | | - Dysoley Lek
- The National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Sovann Yok
- Provincial Health Department, Pailin City, Pailin Province Cambodia
| | - Jack S. Richards
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
- Department of Infectious Diseases, Monash University, Melbourne, Australia
| | - Maxine Anne Whittaker
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Townsville, Australia
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62
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Blasco B, Leroy D, Fidock DA. Antimalarial drug resistance: linking Plasmodium falciparum parasite biology to the clinic. Nat Med 2017; 23:917-928. [PMID: 28777791 DOI: 10.1038/nm.4381] [Citation(s) in RCA: 325] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 06/30/2017] [Indexed: 02/08/2023]
Abstract
The global adoption of artemisinin-based combination therapies (ACTs) in the early 2000s heralded a new era in effectively treating drug-resistant Plasmodium falciparum malaria. However, several Southeast Asian countries have now reported the emergence of parasites that have decreased susceptibility to artemisinin (ART) derivatives and ACT partner drugs, resulting in increasing rates of treatment failures. Here we review recent advances in understanding how antimalarials act and how resistance develops, and discuss new strategies for effectively combatting resistance, optimizing treatment and advancing the global campaign to eliminate malaria.
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Affiliation(s)
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, New York, USA.,Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, New York, USA
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63
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Sweileh WM, Al-Jabi SW, Sawalha AF, AbuTaha AS, Zyoud SH. Bibliometric Analysis of Worldwide Publications on Antimalarial Drug Resistance (2006-2015). Malar Res Treat 2017; 2017:6429410. [PMID: 28856028 PMCID: PMC5569636 DOI: 10.1155/2017/6429410] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/28/2017] [Accepted: 07/10/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND In response to international efforts to control and eradicate malaria, we designed this study to give a bibliometric overview of research productivity in antimalarial drug resistance (AMDR). METHODS Keywords related to AMDR were used to retrieve relevant literature using Scopus database. RESULTS A total of 976 publications with an h-index of 63 were retrieved. The number of publications showed a noticeable increase starting in the early 1990s. The USA was the most productive country with 337 publications equivalent to one-third of worldwide publications in this field. More than two-thirds of publications by the USA (236, 70.03%) were made by international collaboration. Of the top ten productive countries, two countries were from Mekong subregion, particularly Thailand and Cambodia. The Malaria Journal was the most productive journal (136, 13.93%) in this field. Mahidol University (80, 8.20%) in Thailand was the most productive institution. Seven articles in the top-ten list were about artemisinin resistance in Plasmodium falciparum, one was about chloroquine resistance, one was about sulfadoxine-pyrimethamine resistance, and the remaining one was about general multidrug resistance. CONCLUSION Eradication and control of AMDR require continuing research activity to help international health organizations identify spots that require an immediate action to implement appropriate measures.
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Affiliation(s)
- Waleed M. Sweileh
- Department of Physiology, Pharmacology and Toxicology, College of Medicine and Health Sciences, An-Najah National University, Nablus, State of Palestine
| | - Samah W. Al-Jabi
- Department of Clinical and Community Pharmacy, College of Medicine and Health Sciences, An-Najah National University, Nablus, State of Palestine
| | - Ansam F. Sawalha
- Department of Physiology, Pharmacology and Toxicology, College of Medicine and Health Sciences, An-Najah National University, Nablus, State of Palestine
| | - Adham S. AbuTaha
- Department of Physiology, Pharmacology and Toxicology, College of Medicine and Health Sciences, An-Najah National University, Nablus, State of Palestine
| | - Sa'ed H. Zyoud
- Department of Clinical and Community Pharmacy, College of Medicine and Health Sciences, An-Najah National University, Nablus, State of Palestine
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64
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Kumar P, Achieng AO, Rajendran V, Ghosh PC, Singh BK, Rawat M, Perkins DJ, Kempaiah P, Rathi B. Synergistic blending of high-valued heterocycles inhibits growth of Plasmodium falciparum in culture and P. berghei infection in mouse model. Sci Rep 2017; 7:6724. [PMID: 28751747 PMCID: PMC5532363 DOI: 10.1038/s41598-017-06097-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/07/2017] [Indexed: 11/09/2022] Open
Abstract
A series of phthalimide analogues, novelized with high-valued bioactive scaffolds was synthesized by means of click-chemistry under non-conventional microwave heating and evaluated as noteworthy growth inhibitors of Plasmodium falciparum (3D7 and W2) in culture. Analogues 6a, 6h and 6 u showed highest activity to inhibit the growth of the parasite with IC50 values in submicromolar range. Structure-activity correlation indicated the necessity of unsubstituted triazoles and leucine linker to obtain maximal growth inhibition of the parasite. Notably, phthalimide 6a and 6u selectively inhibited the ring-stage growth and parasite maturation. On other hand, phthalimide 6h displayed selective schizonticidal activity. Besides, they displayed synergistic interactions with chloroquine and dihydroartemisinin against parasite. Additional in vivo experiments using P. berghei infected mice showed that administration of 6h and 6u alone, as well as in combination with dihydroartemisinin, substantially reduced the parasite load. The high antimalarial activity of 6h and 6u, coupled with low toxicity advocate their potential role as novel antimalarial agents, either as standalone or combination therapies.
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Affiliation(s)
- Prashant Kumar
- Bio-Organic Research Laboratory, Department of Chemistry, University of Delhi, Delhi, 110007, India
| | - Angela O Achieng
- Department of Internal Medicine, Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, United States of America.,Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya
| | - Vinoth Rajendran
- Department of Biochemistry, University of Delhi South Campus, New Delhi, 110021, India
| | - Prahlad C Ghosh
- Department of Biochemistry, University of Delhi South Campus, New Delhi, 110021, India
| | - Brajendra K Singh
- Bio-Organic Research Laboratory, Department of Chemistry, University of Delhi, Delhi, 110007, India
| | - Manmeet Rawat
- Department of Internal Medicine, Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, United States of America
| | - Douglas J Perkins
- Department of Internal Medicine, Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, United States of America
| | - Prakasha Kempaiah
- Department of Internal Medicine, Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, United States of America.
| | - Brijesh Rathi
- Department of Chemistry, Hansraj College University Enclave, University of Delhi, Delhi, 110007, India. .,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA-02139, United States of America.
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Abstract
Increasing antimalarial drug resistance once again threatens effective antimalarial drug treatment, malaria control, and elimination. Artemisinin combination therapies (ACTs) are first-line treatment for uncomplicated falciparum malaria in all endemic countries, yet partial resistance to artemisinins has emerged in the Greater Mekong Subregion. Concomitant emergence of partner drug resistance is now causing high ACT treatment failure rates in several areas. Genetic markers for artemisinin resistance and several of the partner drugs have been established, greatly facilitating surveillance. Single point mutations in the gene coding for the Kelch propeller domain of the K13 protein strongly correlate with artemisinin resistance. Novel regimens and strategies using existing antimalarial drugs will be needed until novel compounds can be deployed. Elimination of artemisinin resistance will imply elimination of all falciparum malaria from the same areas. In vivax malaria, chloroquine resistance is an increasing problem.
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Affiliation(s)
- Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh 12201, Cambodia
| | - Arjen Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 73170, Thailand
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66
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Dembele L, Ang X, Chavchich M, Bonamy GMC, Selva JJ, Lim MYX, Bodenreider C, Yeung BKS, Nosten F, Russell BM, Edstein MD, Straimer J, Fidock DA, Diagana TT, Bifani P. The Plasmodium PI(4)K inhibitor KDU691 selectively inhibits dihydroartemisinin-pretreated Plasmodium falciparum ring-stage parasites. Sci Rep 2017; 7:2325. [PMID: 28539634 PMCID: PMC5443816 DOI: 10.1038/s41598-017-02440-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/11/2017] [Indexed: 11/23/2022] Open
Abstract
Malaria control and elimination are threatened by the emergence and spread of resistance to artemisinin-based combination therapies (ACTs). Experimental evidence suggests that when an artemisinin (ART)-sensitive (K13 wild-type) Plasmodium falciparum strain is exposed to ART derivatives such as dihydroartemisinin (DHA), a small population of the early ring-stage parasites can survive drug treatment by entering cell cycle arrest or dormancy. After drug removal, these parasites can resume growth. Dormancy has been hypothesized to be an adaptive physiological mechanism that has been linked to recrudescence of parasites after monotherapy with ART and, possibly contributes to ART resistance. Here, we evaluate the in vitro drug sensitivity profile of normally-developing P. falciparum ring stages and DHA-pretreated dormant rings (DP-rings) using a panel of antimalarial drugs, including the Plasmodium phosphatidylinositol-4-OH kinase (PI4K)-specific inhibitor KDU691. We report that while KDU691 shows no activity against rings, it is highly inhibitory against DP-rings; a drug effect opposite to that of ART. Moreover, we provide evidence that KDU691 also kills DP-rings of P. falciparum ART-resistant strains expressing mutant K13.
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Affiliation(s)
- L Dembele
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - X Ang
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - M Chavchich
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, QLD, 4051, Australia
| | - G M C Bonamy
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - J J Selva
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - M Yi-Xiu Lim
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - C Bodenreider
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - B K S Yeung
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - F 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, Oxford, UK
| | - B M Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - M D Edstein
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, QLD, 4051, Australia
| | - J Straimer
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, 10032, USA
| | - D A Fidock
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, 10032, USA.,Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - T T Diagana
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore
| | - P Bifani
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, 138670, Singapore, Singapore. .,Department of Microbiology and Immunology Program, Yong Loo Lin School of Medicine, Life Sciences Institute, National University of Singapore, 119077, Singapore, Singapore.
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Phok S, Phanalasy S, Thein ST, Likhitsup A. Private sector opportunities and threats to achieving malaria elimination in the Greater Mekong Subregion: results from malaria outlet surveys in Cambodia, the Lao PDR, Myanmar, and Thailand. Malar J 2017; 16:180. [PMID: 28464945 PMCID: PMC5414126 DOI: 10.1186/s12936-017-1800-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 04/05/2017] [Indexed: 11/10/2022] Open
Abstract
Background The aim of this paper is to review multi-country evidence of private sector adherence to national regulations, guidelines, and quality-assurance standards for malaria case management and to document current coverage of private sector engagement and support through ACTwatch outlet surveys implemented in 2015 and 2016. Results Over 76,168 outlets were screened, and approximately 6500 interviews were conducted (Cambodia, N = 1303; the Lao People’s Democratic Republic (PDR), N = 724; Myanmar, N = 4395; and Thailand, N = 74). There was diversity in the types of private sector outlets providing malaria treatment across countries, and the extent to which they were authorized to test and treat for malaria differed. Among outlets stocking at least one anti-malarial, public sector availability of the first-line treatment for uncomplicated Plasmodium falciparum or Plasmodium vivax malaria was >75%. In the anti-malarial stocking private sector, first-line treatment availability was variable (Cambodia, 70.9%; the Lao PDR, 40.8%; Myanmar P. falciparum = 42.7%, P. vivax = 19.6%; Thailand P. falciparum = 19.6%, P. vivax = 73.3%), as was availability of second-line treatment (the Lao PDR, 74.9%; Thailand, 39.1%; Myanmar, 19.8%; and Cambodia, 0.7%). Treatment not in the National Treatment Guidelines (NTGs) was most common in Myanmar (35.8%) and Cambodia (34.0%), and was typically stocked by the informal sector. The majority of anti-malarials distributed in Cambodia and Myanmar were first-line P. falciparum or P. vivax treatments (90.3% and 77.1%, respectively), however, 8.8% of the market share in Cambodia was treatment not in the NTGs (namely chloroquine) and 17.6% in Myanmar (namely oral artemisinin monotherapy). In the Lao PDR, approximately 9 in 10 anti-malarials distributed in the private sector were second-line treatments—typically locally manufactured chloroquine. In Cambodia, 90% of anti-malarials were distributed through outlets that had confirmatory testing available. Over half of all anti-malarial distribution was by outlets that did not have confirmatory testing available in the Lao PDR (54%) and Myanmar (59%). Availability of quality-assured rapid diagnostic tests (RDT) amongst the RDT-stocking public sector ranged from 99.3% in the Lao PDR to 80.1% in Cambodia. In Cambodia, the Lao PDR, and Myanmar, less than 50% of the private sector reportedly received engagement (access to subsidized commodities, supervision, training or caseload reporting), which was most common among private health facilities and pharmacies. Conclusions Findings from this multi-country study suggest that Cambodia, the Lao PDR, Myanmar, and Thailand are generally in alignment with national regulations, treatment guidelines, and quality-assurance standards. However, important gaps persist in the private sector which pose a threat to national malaria control and elimination goals. Several options are discussed to help align the private sector anti-malarial market with national elimination strategies. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1800-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Sochea Phok
- Population Services Khmer, 29 334 St, Boeung Keng Kang, P. O. Box 258, Phnom Penh, Cambodia
| | - Saysana Phanalasy
- Population Services International Lao PDR, T4 Road Unit 16, Donkai Village, P. O. Box 8723, Vientiane, Lao People's Democratic Republic
| | - Si Thu Thein
- Population Services International Myanmar, 16 West Shwe Gone Dine 4th St, Bahan Township, Yangon, Myanmar
| | - Asawin Likhitsup
- , 108/210 Siphraya River View Condo, Yotha Rd, Sampanthawong, Bangkok, 10100, Thailand
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68
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How to Contain Artemisinin- and Multidrug-Resistant Falciparum Malaria. Trends Parasitol 2017; 33:353-363. [DOI: 10.1016/j.pt.2017.01.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 11/18/2016] [Accepted: 01/05/2017] [Indexed: 11/20/2022]
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69
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Mungthin M, Watanatanasup E, Sitthichot N, Suwandittakul N, Khositnithikul R, Ward SA. Influence of the pfmdr1 Gene on In Vitro Sensitivities of Piperaquine in Thai Isolates of Plasmodium falciparum. Am J Trop Med Hyg 2017; 96:624-629. [PMID: 28044042 DOI: 10.4269/ajtmh.16-0668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Piperaquine combined with dihydroartemisinin is one of the artemisinin derivative combination therapies, which can replace artesunate-mefloquine in treating uncomplicated falciparum malaria in Thailand. The aim of this study was to determine the in vitro sensitivity of Thai Plasmodium falciparum isolates against piperaquine and the influence of the pfmdr1 gene on in vitro response. One hundred and thirty-seven standard laboratory and adapted Thai isolates of P. falciparum were assessed for in vitro piperaquine sensitivity. Polymorphisms of the pfmdr1 gene were determined by polymerase chain reaction methods. The mean and standard deviation of the piperaquine IC50 in Thai isolates of P. falciparum were 16.7 ± 6.3 nM. The parasites exhibiting chloroquine IC50 of ≥ 100 nM were significantly less sensitive to piperaquine compared with the parasite with chloroquine IC50 of < 100 nM. No significant association between the pfmdr1 copy number and piperaquine IC50 values was found. In contrast, the parasites containing the pfmdr1 86Y allele exhibited significantly reduced piperaquine sensitivity. Before nationwide implementation of dihydroartemisinin-piperaquine as the first-line treatment in Thailand, in vitro and in vivo evaluations of this combination should be performed especially in areas where parasites containing the pfmdr1 86Y allele are predominant such as the Thai-Malaysian border.
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Affiliation(s)
- Mathirut Mungthin
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok, Thailand
| | | | - Naruemon Sitthichot
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok, Thailand
| | | | | | - Stephen A Ward
- Division of Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Impact of Extended Duration of Artesunate Treatment on Parasitological Outcome in a Cytocidal Murine Malaria Model. Antimicrob Agents Chemother 2017; 61:AAC.02499-16. [PMID: 28096162 DOI: 10.1128/aac.02499-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/11/2017] [Indexed: 11/20/2022] Open
Abstract
Artemisinin-based combination therapies are a key pillar in global malaria control and are recommended as a first-line Plasmodium falciparum treatment. They rely upon a rapid 4-log-unit reduction in parasitemia by artemisinin compounds with a short half-life and the killing of remaining parasites by a partner compound with a longer half-life. Current treatment guidelines stipulate giving three 24-h-interval doses or six 12-h-interval doses over a 3-day period. Due to the short half-life of artesunate and artemether, almost all of the resulting cytocidal activity is confined within a single 48-h asexual P. falciparum cycle. Here, we utilized a luciferase reporter, Plasmodium berghei ANKA, in a cytocidal model in which treatment was initiated at high parasitemia, allowing us to monitor a greater than 3-log-unit reduction in parasite density, as well as 30-day survival. In this study, we demonstrated that increasing the artesunate duration from spanning one asexual cycle to spanning three asexual cycles while keeping the total dose constant results in enhanced cytocidal activity. Single daily artesunate doses at 50 mg/kg of body weight over 7 days were the minimum necessary for curative monotherapy. In combination with a single sub-human-equivalent dose of the partner drug amodiaquine or piperaquine, the three-asexual-cycle artesunate duration was able to cure 75% and 100% of mice, respectively, whereas 0% and 33% cures were achieved with the single-asexual-cycle artesunate duration. In summary, cytocidal activity of the artemisinin compounds, such as artesunate, can be improved solely by altering the dosing duration.
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Amato R, Lim P, Miotto O, Amaratunga C, Dek D, Pearson RD, Almagro-Garcia J, Neal AT, Sreng S, Suon S, Drury E, Jyothi D, Stalker J, Kwiatkowski DP, Fairhurst RM. Genetic markers associated with dihydroartemisinin-piperaquine failure in Plasmodium falciparum malaria in Cambodia: a genotype-phenotype association study. THE LANCET. INFECTIOUS DISEASES 2017; 17:164-173. [PMID: 27818095 PMCID: PMC5564489 DOI: 10.1016/s1473-3099(16)30409-1] [Citation(s) in RCA: 257] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND As the prevalence of artemisinin-resistant Plasmodium falciparum malaria increases in the Greater Mekong subregion, emerging resistance to partner drugs in artemisinin combination therapies seriously threatens global efforts to treat and eliminate this disease. Molecular markers that predict failure of artemisinin combination therapy are urgently needed to monitor the spread of partner drug resistance, and to recommend alternative treatments in southeast Asia and beyond. METHODS We did a genome-wide association study of 297 P falciparum isolates from Cambodia to investigate the relationship of 11 630 exonic single-nucleotide polymorphisms (SNPs) and 43 copy number variations (CNVs) with in-vitro piperaquine 50% inhibitory concentrations (IC50s), and tested whether these genetic variants are markers of treatment failure with dihydroartemisinin-piperaquine. We then did a survival analysis of 133 patients to determine whether candidate molecular markers predicted parasite recrudescence following dihydroartemisinin-piperaquine treatment. FINDINGS Piperaquine IC50s increased significantly from 2011 to 2013 in three Cambodian provinces (2011 vs 2013 median IC50s: 20·0 nmol/L [IQR 13·7-29·0] vs 39·2 nmol/L [32·8-48·1] for Ratanakiri, 19·3 nmol/L [15·1-26·2] vs 66·2 nmol/L [49·9-83·0] for Preah Vihear, and 19·6 nmol/L [11·9-33·9] vs 81·1 nmol/L [61·3-113·1] for Pursat; all p≤10-3; Kruskal-Wallis test). Genome-wide analysis of SNPs identified a chromosome 13 region that associates with raised piperaquine IC50s. A non-synonymous SNP (encoding a Glu415Gly substitution) in this region, within a gene encoding an exonuclease, associates with parasite recrudescence following dihydroartemisinin-piperaquine treatment. Genome-wide analysis of CNVs revealed that a single copy of the mdr1 gene on chromosome 5 and a novel amplification of the plasmepsin 2 and plasmepsin 3 genes on chromosome 14 also associate with raised piperaquine IC50s. After adjusting for covariates, both exo-E415G and plasmepsin 2-3 markers significantly associate (p=3·0 × 10-8 and p=1·7 × 10-7, respectively) with decreased treatment efficacy (survival rates 0·38 [95% CI 0·25-0·51] and 0·41 [0·28-0·53], respectively). INTERPRETATION The exo-E415G SNP and plasmepsin 2-3 amplification are markers of piperaquine resistance and dihydroartemisinin-piperaquine failures in Cambodia, and can help monitor the spread of these phenotypes into other countries of the Greater Mekong subregion, and elucidate the mechanism of piperaquine resistance. Since plasmepsins are involved in the parasite's haemoglobin-to-haemozoin conversion pathway, targeted by related antimalarials, plasmepsin 2-3 amplification probably mediates piperaquine resistance. FUNDING Intramural Research Program of the US National Institute of Allergy and Infectious Diseases, National Institutes of Health, Wellcome Trust, Bill & Melinda Gates Foundation, Medical Research Council, and UK Department for International Development.
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Affiliation(s)
- Roberto Amato
- Wellcome Trust Sanger Institute, Hinxton, UK; Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford, UK.
| | - Pharath Lim
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA; National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Olivo Miotto
- Wellcome Trust Sanger Institute, Hinxton, UK; Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Chanaki Amaratunga
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Dalin Dek
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Richard D Pearson
- Wellcome Trust Sanger Institute, Hinxton, UK; Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford, UK
| | - Jacob Almagro-Garcia
- Wellcome Trust Sanger Institute, Hinxton, UK; Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford, UK
| | - Aaron T Neal
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Sokunthea Sreng
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Seila Suon
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | | | | | - Jim Stalker
- Wellcome Trust Sanger Institute, Hinxton, UK
| | - Dominic P Kwiatkowski
- Wellcome Trust Sanger Institute, Hinxton, UK; Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford, UK
| | - Rick M Fairhurst
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA.
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Bayih AG, Folefoc A, Mohon AN, Eagon S, Anderson M, Pillai DR. In vitro and in vivo anti-malarial activity of novel harmine-analog heat shock protein 90 inhibitors: a possible partner for artemisinin. Malar J 2016; 15:579. [PMID: 27903279 PMCID: PMC5131496 DOI: 10.1186/s12936-016-1625-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/18/2016] [Indexed: 11/13/2022] Open
Abstract
Background The emergence of artemisinin-resistant Plasmodium falciparum strains poses a serious challenge to the control of malaria. This necessitates the development of new anti-malarial drugs. Previous studies have shown that the natural beta-carboline alkaloid harmine is a promising anti-malarial agent targeting the P. falciparum heat-shock protein 90 (PfHsp90). The aim of this study was to test the anti-malarial activity of harmine analogues. Methods Forty-two harmine analogues were synthesized and the binding of these analogues to P. falciparum heat shock protein 90 was investigated. The in vitro anti-malarial activity of two of the analogues, 17A and 21A, was evaluated using a 72-h growth inhibition assay. The in vivo anti-malarial activity was tested in Plasmodium berghei infection of BALB/c mice. The potential of 21A for a combination treatment with artemisinin was evaluated using in vivo combination study with dihydro-artemisinin in BALB/c mice. Cytotoxicity of the harmine analogues was tested in vitro using HepG2 and HeLa cell lines. Results 17A and 21A bound to PfHsp90 with average IC50 values of 12.2 ± 2.3 and 23.1 ± 8.8 µM, respectively. They also inhibited the P. falciparum W2 strain with average IC50 values of 4.2 ± 1.3 and 5.7 ± 1.7 µM, respectively. In vivo, three daily injections of P. berghei-infected BALB/c mice with 100 mg/kg of either 17A or 21A showed significant reduction in parasitaemia with a 51.5 and 56.1% reduction, respectively. Mice treated with 17A and 21A showed a median survival time of 11 and 14 days, respectively, while the vehicle control mice survived a median of only 8.5 days. A dose-ranging experiment with 21A showed that the compound has a dose-dependent anti-malarial effect. Furthermore, treatment of infected mice with a combination of 21A and dihydroartemisinin (DHA) showed a dramatic reduction in parasitaemia compared to treatment with DHA alone. Conclusion A novel and non-toxic harmine analogue has been synthesized which binds to PfHsp90 protein, inhibits P. falciparum in vitro at micromolar concentration, reduces parasitaemia and prolongs survival of P. berghei-infected mice with an additive anti-malarial effect when combined with DHA.
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Affiliation(s)
- Abebe Genetu Bayih
- Department of Pathology and Laboratory Medicine, MIID and Medicine, University of Calgary, Calgary, AB, Canada. .,Department of Medical Parasitology, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
| | - Asongna Folefoc
- Department of Pathology and Laboratory Medicine, MIID and Medicine, University of Calgary, Calgary, AB, Canada
| | - Abu Naser Mohon
- Department of Pathology and Laboratory Medicine, MIID and Medicine, University of Calgary, Calgary, AB, Canada
| | - Scott Eagon
- Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA, USA
| | - Marc Anderson
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA, USA
| | - Dylan R Pillai
- Department of Pathology and Laboratory Medicine, MIID and Medicine, University of Calgary, Calgary, AB, Canada
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Srimuang K, Miotto O, Lim P, Fairhurst RM, Kwiatkowski DP, Woodrow CJ, Imwong M. Analysis of anti-malarial resistance markers in pfmdr1 and pfcrt across Southeast Asia in the Tracking Resistance to Artemisinin Collaboration. Malar J 2016; 15:541. [PMID: 27825353 PMCID: PMC5101715 DOI: 10.1186/s12936-016-1598-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 10/31/2016] [Indexed: 01/07/2023] Open
Abstract
Background Declining anti-malarial efficacy of artemisinin-based combination therapy, and reduced Plasmodium falciparum susceptibility to individual anti-malarials are being documented across an expanding area of Southeast Asia (SEA). Genotypic markers complement phenotypic studies in assessing the efficacy of individual anti-malarials. Methods The markers pfmdr1 and pfcrt were genotyped in parasite samples obtained in 2011–2014 at 14 TRAC (Tracking Resistance to Artemisinin Collaboration) sites in mainland Southeast Asia using a combination of PCR and next-generation sequencing methods. Results Pfmdr1 amplification, a marker of mefloquine and lumefantrine resistance, was highly prevalent at Mae Sot on the Thailand–Myanmar border (59.8% of isolates) and common (more than 10%) at sites in central Myanmar, eastern Thailand and western Cambodia; however, its prevalence was lower than previously documented in Pailin, western Cambodia. The pfmdr1 Y184F mutation was common, particularly in and around Cambodia, and the F1226Y mutation was found in about half of samples in Mae Sot. The functional significance of these two mutations remains unclear. Other previously documented pfmdr1 mutations were absent or very rare in the region. The pfcrt mutation K76T associated with chloroquine resistance was found in 98.2% of isolates. The CVIET haplotype made up 95% or more of isolates in western SEA while the CVIDT haplotype was common (30–40% of isolates) in north and northeastern Cambodia, southern Laos, and southern Vietnam. Conclusions These findings generate cause for concern regarding the mid-term efficacy of artemether–lumefantrine in Myanmar, while the absence of resistance-conferring pfmdr1 mutations and SVMNT pfcrt haplotypes suggests that amodiaquine could be an efficacious component of anti-malarial regimens in SEA. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1598-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Krongkan Srimuang
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Olivo Miotto
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand.,Wellcome Trust Sanger Institute, Hinxton, UK.,Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Pharath Lim
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Dominic P Kwiatkowski
- Wellcome Trust Sanger Institute, Hinxton, UK.,Medical Research Council (MRC) Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Charles J Woodrow
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand.,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand.
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Witkowski B, Duru V, Khim N, Ross LS, Saintpierre B, Beghain J, Chy S, Kim S, Ke S, Kloeung N, Eam R, Khean C, Ken M, Loch K, Bouillon A, Domergue A, Ma L, Bouchier C, Leang R, Huy R, Nuel G, Barale JC, Legrand E, Ringwald P, Fidock DA, Mercereau-Puijalon O, Ariey F, Ménard D. A surrogate marker of piperaquine-resistant Plasmodium falciparum malaria: a phenotype-genotype association study. THE LANCET. INFECTIOUS DISEASES 2016; 17:174-183. [PMID: 27818097 PMCID: PMC5266792 DOI: 10.1016/s1473-3099(16)30415-7] [Citation(s) in RCA: 257] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/26/2016] [Accepted: 09/30/2016] [Indexed: 11/30/2022]
Abstract
Background Western Cambodia is the epicentre of Plasmodium falciparum multidrug resistance and is facing high rates of dihydroartemisinin–piperaquine treatment failures. Genetic tools to detect the multidrug-resistant parasites are needed. Artemisinin resistance can be tracked using the K13 molecular marker, but no marker exists for piperaquine resistance. We aimed to identify genetic markers of piperaquine resistance and study their association with dihydroartemisinin–piperaquine treatment failures. Methods We obtained blood samples from Cambodian patients infected with P falciparum and treated with dihydroartemisinin–piperaquine. Patients were followed up for 42 days during the years 2009–15. We established in-vitro and ex-vivo susceptibility profiles for a subset using piperaquine survival assays. We determined whole-genome sequences by Illumina paired-reads sequencing, copy number variations by qPCR, RNA concentrations by qRT-PCR, and protein concentrations by immunoblotting. Fisher’s exact and non-parametric Wilcoxon rank-sum tests were used to identify significant differences in single-nucleotide polymorphisms or copy number variants, respectively, for differential distribution between piperaquine-resistant and piperaquine-sensitive parasite lines. Findings Whole-genome exon sequence analysis of 31 culture-adapted parasite lines associated amplification of the plasmepsin 2–plasmepsin 3 gene cluster with in-vitro piperaquine resistance. Ex-vivo piperaquine survival assay profiles of 134 isolates correlated with plasmepsin 2 gene copy number. In 725 patients treated with dihydroartemisinin–piperaquine, multicopy plasmepsin 2 in the sample collected before treatment was associated with an adjusted hazard ratio (aHR) for treatment failure of 20·4 (95% CI 9·1–45·5, p<0·0001). Multicopy plasmepsin 2 predicted dihydroartemisinin–piperaquine failures with 0·94 (95% CI 0·88–0·98) sensitivity and 0·77 (0·74–0·81) specificity. Analysis of samples collected across the country from 2002 to 2015 showed that the geographical and temporal increase of the proportion of multicopy plasmepsin 2 parasites was highly correlated with increasing dihydroartemisinin–piperaquine treatment failure rates (r=0·89 [95% CI 0·77–0·95], p<0·0001, Spearman’s coefficient of rank correlation). Dihydroartemisinin–piperaquine efficacy at day 42 fell below 90% when the proportion of multicopy plasmepsin 2 parasites exceeded 22%. Interpretation Piperaquine resistance in Cambodia is strongly associated with amplification of plasmepsin 2–3, encoding haemoglobin-digesting proteases, regardless of the location. Multicopy plasmepsin 2 constitutes a surrogate molecular marker to track piperaquine resistance. A molecular toolkit combining plasmepsin 2 with K13 and mdr1 monitoring should provide timely information for antimalarial treatment and containment policies. Funding Institut Pasteur in Cambodia, Institut Pasteur Paris, National Institutes of Health, WHO, Agence Nationale de la Recherche, Investissement d’Avenir programme, Laboratoire d’Excellence Integrative “Biology of Emerging Infectious Diseases”.
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Affiliation(s)
- Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia; Malaria Translational Research Unit, Institut Pasteur, Paris, France; Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Valentine Duru
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia; Malaria Translational Research Unit, Institut Pasteur, Paris, France; Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Leila S Ross
- Department of Microbiology and Immunology and Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | | | - Johann Beghain
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Sophy Chy
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Saorin Kim
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Sopheakvatey Ke
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Nimol Kloeung
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Rotha Eam
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Chanra Khean
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Malen Ken
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Kaknika Loch
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Anthony Bouillon
- Malaria Translational Research Unit, Institut Pasteur, Paris, France; Institut Pasteur in Cambodia, Phnom Penh, Cambodia; Structural Microbiology Unit, Biology of Malaria Targets Group, Department of Structural Biology and Chemistry and CNRS, UMR3528, Institut Pasteur, Paris, France
| | - Anais Domergue
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Laurence Ma
- Plate-forme Génomique, Département Génomes et Génétique, Institut Pasteur, Paris, France
| | - Christiane Bouchier
- Plate-forme Génomique, Département Génomes et Génétique, Institut Pasteur, Paris, France
| | - Rithea Leang
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Rekol Huy
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Grégory Nuel
- Laboratoire de Mathématiques Appliquées (MAP5) UMR CNRS 8145, Université Paris Descartes, Paris, France
| | - Jean-Christophe Barale
- Malaria Translational Research Unit, Institut Pasteur, Paris, France; Institut Pasteur in Cambodia, Phnom Penh, Cambodia; Structural Microbiology Unit, Biology of Malaria Targets Group, Department of Structural Biology and Chemistry and CNRS, UMR3528, Institut Pasteur, Paris, France
| | - Eric Legrand
- Malaria Translational Research Unit, Institut Pasteur, Paris, France; Institut Pasteur in Cambodia, Phnom Penh, Cambodia; Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Pascal Ringwald
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - David A Fidock
- Department of Microbiology and Immunology and Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | | | - Frédéric Ariey
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France; Institut Cochin Inserm U1016, Université Paris-Descartes, Sorbonne Paris Cité, and Laboratoire de Parasitologie-Mycologie, Hôpital Cochin, Paris, France
| | - Didier Ménard
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia; Malaria Translational Research Unit, Institut Pasteur, Paris, France; Institut Pasteur in Cambodia, Phnom Penh, Cambodia.
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75
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Dondorp AM. New genetic marker for piperaquine resistance in Plasmodium falciparum. THE LANCET. INFECTIOUS DISEASES 2016; 17:119-121. [PMID: 27818096 DOI: 10.1016/s1473-3099(16)30414-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 10/03/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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76
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Brazeau NF, Hathaway N, Parobek CM, Lin JT, Bailey JA, Lon C, Saunders DL, Juliano JJ. Longitudinal Pooled Deep Sequencing of the Plasmodium vivax K12 Kelch Gene in Cambodia Reveals a Lack of Selection by Artemisinin. Am J Trop Med Hyg 2016; 95:1409-1412. [PMID: 27799638 DOI: 10.4269/ajtmh.16-0566] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 08/30/2016] [Indexed: 11/07/2022] Open
Abstract
The emergence of artemisinin resistance among Plasmodium falciparum in the Greater Mekong subregion threatens malaria control interventions and is associated with multiple unique mutations in K13 (PF3D7_1343700). The aim of this study was to survey Cambodian Plasmodium vivax for mutations in the K13 ortholog (K12, PVX_083080) that might similarly confer artemisinin resistance. Extracted DNA from Cambodian isolates collected between 2009 and 2012 was pooled by province and year and submitted for next-generation sequencing. Single-nucleotide polymorphisms (SNPs) were identified using a pile-up approach that detected minority SNPs. Among the 14 pools, we found six unique SNPs, including three nonsynonymous SNPs, across six codons in K12 However, none of the SNPs were orthologous to artemisinin resistance-conferring mutations in PF3D7_1343700, and nonsynonymous changes did not persist through time within populations. These results suggest a lack of selection in the P. vivax population in Cambodia due to artemisinin drug pressure.
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Affiliation(s)
- Nicholas F Brazeau
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina.,Doctor of Medicine/Doctor of Philosophy Program, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Nicholas Hathaway
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts.,School of Medicine, University of Massachusetts, Worcester, Massachusetts
| | - Christian M Parobek
- Doctor of Medicine/Doctor of Philosophy Program, University of North Carolina School of Medicine, Chapel Hill, North Carolina.,Curriculum in Genetics and Molecular Biology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Jessica T Lin
- Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Jeffrey A Bailey
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts.,School of Medicine, University of Massachusetts, Worcester, Massachusetts
| | - Chanthap Lon
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - David L Saunders
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Jonathan J Juliano
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina. .,Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts.,Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina
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77
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Leang R, Khu NH, Mukaka M, Debackere M, Tripura R, Kheang ST, Chy S, Kak N, Buchy P, Tarantola A, Menard D, Roca-Felterer A, Fairhurst RM, Kheng S, Muth S, Ngak S, Dondorp AM, White NJ, Taylor WRJ. An optimised age-based dosing regimen for single low-dose primaquine for blocking malaria transmission in Cambodia. BMC Med 2016; 14:171. [PMID: 27784313 PMCID: PMC5081959 DOI: 10.1186/s12916-016-0701-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 09/20/2016] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND In 2012, the World Health Organization recommended the addition of single low-dose primaquine (SLDPQ, 0.25 mg base/kg body weight) to artemisinin combination therapies to block the transmission of Plasmodium falciparum without testing for glucose-6-phosphate dehydrogenase deficiency. The targeted group was non-pregnant patients aged ≥ 1 year (later changed to ≥ 6 months) with acute uncomplicated falciparum malaria, primarily in countries with artemisinin-resistant P. falciparum (ARPf). No dosing regimen was suggested, leaving malaria control programmes and clinicians in limbo. Therefore, we designed a user-friendly, age-based SLDPQ regimen for Cambodia, the country most affected by ARPf. METHODS By reviewing primaquine's pharmacology, we defined a therapeutic dose range of 0.15-0.38 mg base/kg (9-22.5 mg in a 60-kg adult) for a therapeutic index of 2.5. Primaquine doses (1-20 mg) were tested using a modelled, anthropometric database of 28,138 Cambodian individuals (22,772 healthy, 4119 with malaria and 1247 with other infections); age distributions were: 0.5-4 years (20.0 %, n = 5640), 5-12 years (9.1 %, n = 2559), 13-17 years (9.1 %, n = 2550), and ≥ 18 years (61.8 %, n = 17,389). Optimal age-dosing groups were selected according to calculated mg base/kg doses and proportions of individuals receiving a therapeutic dose. RESULTS Four age-dosing bands were defined: (1) 0.5-4 years, (2) 5-9 years, (3) 10-14 years, and (4) ≥15 years to receive 2.5, 5, 7.5, and 15 mg of primaquine base, resulting in therapeutic doses in 97.4 % (5494/5640), 90.5 % (1511/1669), 97.7 % (1473/1508), and 95.7 % (18,489/19,321) of individuals, respectively. Corresponding median (1st-99th centiles) mg base/kg doses of primaquine were (1) 0.23 (0.15-0.38), (2) 0.29 (0.18-0.45), (3) 0.27 (0.15-0.39), and (4) 0.29 (0.20-0.42). CONCLUSIONS This age-based SLDPQ regimen could contribute substantially to malaria elimination and requires urgent evaluation in Cambodia and other countries with similar anthropometric characteristics. It guides primaquine manufacturers on suitable tablet strengths and doses for paediatric-friendly formulations. Development of similar age-based dosing recommendations for Africa is needed.
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Affiliation(s)
- Rithea Leang
- National Center for Parasitology, Entomology and Malaria Control, Corner St. 92, Trapeng Svay Village, Sangkat Phnom Penh, Thmei, Khan Sen Sok, Phnom Penh, Cambodia
| | - Naw Htee Khu
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand.,Oxford Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Mark Debackere
- MSF Belgium Cambodia Malaria Program, #19, Street 388, Sangkat Tuol Svay Prey, Khan Chamkarmon, PO Box 1933, Phnom Penh, Cambodia
| | - Rupam Tripura
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
| | - Soy Ty Kheang
- University Research Co., LLC, MK Building, House #10 (2nd floor), St. 214, Chey Chumneas, Daun Penh, Phnom Penh, Cambodia
| | - Say Chy
- University Research Co., LLC, MK Building, House #10 (2nd floor), St. 214, Chey Chumneas, Daun Penh, Phnom Penh, Cambodia
| | - Neeraj Kak
- University Research Co., LLC Washington DC: 7200 Wisconsin Ave, Bethesda, MD, 20814, USA
| | - Philippe Buchy
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Arnaud Tarantola
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Didier Menard
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Arantxa Roca-Felterer
- Malaria Consortium, House #91 Street 95, Boeung Trabek, Chamkar Morn, Phnom Penh, Cambodia
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Sim Kheng
- National Center for Parasitology, Entomology and Malaria Control, Corner St. 92, Trapeng Svay Village, Sangkat Phnom Penh, Thmei, Khan Sen Sok, Phnom Penh, Cambodia
| | - Sinoun Muth
- National Center for Parasitology, Entomology and Malaria Control, Corner St. 92, Trapeng Svay Village, Sangkat Phnom Penh, Thmei, Khan Sen Sok, Phnom Penh, Cambodia
| | - Song Ngak
- FHI 360 Cambodia Office, #03, Street 330 Boeung Keng Kang III Khan Chamkamon, PO Box: 2586, Phnom Penh, Cambodia
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand.,Oxford Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand.,Oxford Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Walter Robert John Taylor
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand. .,Oxford Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK. .,Centre de Médecine Humanitaire, Hôpitaux Universitaires de Genève, Genève, Switzerland.
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78
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Chaorattanakawee S, Lon C, Jongsakul K, Gawee J, Sok S, Sundrakes S, Kong N, Thamnurak C, Chann S, Chattrakarn S, Praditpol C, Buathong N, Uthaimongkol N, Smith P, Sirisopana N, Huy R, Prom S, Fukuda MM, Bethell D, Walsh DS, Lanteri C, Saunders D. Ex vivo piperaquine resistance developed rapidly in Plasmodium falciparum isolates in northern Cambodia compared to Thailand. Malar J 2016; 15:519. [PMID: 27769299 PMCID: PMC5075182 DOI: 10.1186/s12936-016-1569-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/07/2016] [Indexed: 12/29/2022] Open
Abstract
Background The recent dramatic decline in dihydroartemisinin-piperaquine (DHA-PPQ) efficacy in northwestern Cambodia has raised concerns about the rapid spread of piperaquine resistance just as DHA-PPQ is being introduced as first-line therapy in neighbouring countries. Methods Ex vivo parasite susceptibilities were tracked to determine the rate of progression of DHA, PPQ and mefloquine (MQ) resistance from sentinel sites on the Thai–Cambodian and Thai–Myanmar borders from 2010 to 2015. Immediate ex vivo (IEV) histidine-rich protein 2 (HRP-2) assays were used on fresh patient Plasmodium falciparum isolates to determine drug susceptibility profiles. Results IEV HRP-2 assays detected the precipitous emergence of PPQ resistance in Cambodia beginning in 2013 when 40 % of isolates had an IC90 greater than the upper limit of prior years, and this rate doubled to 80 % by 2015. In contrast, Thai–Myanmar isolates from 2013 to 14 remained PPQ-sensitive, while northeastern Thai isolates appeared to have an intermediate resistance profile. The opposite trend was observed for MQ where Cambodian isolates appeared to have a modest increase in overall sensitivity during the same period, with IC50 declining to median levels comparable to those found in Thailand. A significant association between increased PPQ IC50 and IC90 among Cambodian isolates with DHA-PPQ treatment failure was observed. Nearly all Cambodian and Thai isolates were deemed artemisinin resistant with a >1 % survival rate for DHA in the ring-stage assay (RSA), though there was no correlation among isolates to indicate cross-resistance between PPQ and artemisinins. Conclusions Clinical DHA-PPQ failures appear to be associated with declines in the long-acting partner drug PPQ, though sensitivity appears to remain largely intact for now in western Thailand. Rapid progression of PPQ resistance associated with DHA-PPQ treatment failures in northern Cambodia limits drugs of choice in this region, and urgently requires alternative therapy. The temporary re-introduction of artesunate AS-MQ is the current response to PPQ resistance in this area, due to inverse MQ and PPQ resistance patterns. This will require careful monitoring for re-emergence of MQ resistance, and possible simultaneous resistance to all three drugs (AS, MQ and PPQ). Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1569-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Suwanna Chaorattanakawee
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand.,Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Chanthap Lon
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand. .,USAMC-AFRIMS, Phnom Penh, Cambodia.
| | - Krisada Jongsakul
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | | | - Somethy Sok
- Royal Cambodian Armed Forces, Phnom Penh, Cambodia
| | - Siratchana Sundrakes
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Nareth Kong
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Chatchadaporn Thamnurak
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | | | - Sorayut Chattrakarn
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Chantida Praditpol
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Nillawan Buathong
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Nichapat Uthaimongkol
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Philip Smith
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | | | - Rekol Huy
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | | | - Mark M Fukuda
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Delia Bethell
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Douglas S Walsh
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Charlotte Lanteri
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand.,Department of Pathology and Area Laboratory Services, Microbiology Section, Brooke Army Medical Center, San Antonio, TX, USA
| | - David Saunders
- US Army Medical Component-Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
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79
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Siv S, Roca-Feltrer A, Vinjamuri SB, Bouth DM, Lek D, Rashid MA, By NP, Popovici J, Huy R, Menard D. Plasmodium vivax Malaria in Cambodia. Am J Trop Med Hyg 2016; 95:97-107. [PMID: 27708187 PMCID: PMC5201228 DOI: 10.4269/ajtmh.16-0208] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/25/2016] [Indexed: 11/16/2022] Open
Abstract
The Cambodian National Strategic Plan for Elimination of Malaria aims to move step by step toward elimination of malaria across Cambodia with an initial focus on Plasmodium falciparum malaria before achieving elimination of all forms of malaria, including Plasmodium vivax in 2025. The emergence of artemisinin-resistant P. falciparum in western Cambodia over the last decade has drawn global attention to support the ultimate goal of P. falciparum elimination, whereas the control of P. vivax lags much behind, making the 2025 target gradually less achievable unless greater attention is given to P. vivax elimination in the country. The following review presents in detail the past and current situation regarding P. vivax malaria, activities of the National Malaria Control Program, and interventional measures applied. Constraints and obstacles that can jeopardize our efforts to eliminate this parasite species are discussed.
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Affiliation(s)
- Sovannaroth Siv
- National Center for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
| | | | - Seshu Babu Vinjamuri
- National Center for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
| | - Denis Mey Bouth
- World Health Organization, Country Office, Phnom Penh, Cambodia
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
| | | | - Ngau Peng By
- Malaria Consortium Cambodia, Phnom Penh, Cambodia
| | - Jean Popovici
- Institute Pasteur in Cambodia (IPC), Phnom Penh, Cambodia
| | - Rekol Huy
- National Center for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
| | - Didier Menard
- Institute Pasteur in Cambodia (IPC), Phnom Penh, Cambodia
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80
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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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81
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Abstract
Introduction: Relapses are important contributors to illness and morbidity in Plasmodium vivax and P. ovale infections. Relapse prevention (radical cure) with primaquine is required for optimal management, control and ultimately elimination of Plasmodium vivax malaria. A review was conducted with publications in English, French, Portuguese and Spanish using the search terms ‘P. vivax’ and ‘relapse’. Areas covered: Hypnozoites causing relapses may be activated weeks or months after initial infection. Incidence and temporal patterns of relapse varies geographically. Relapses derive from parasites either genetically similar or different from the primary infection indicating that some derive from previous infections. Malaria illness itself may activate relapse. Primaquine is the only widely available treatment for radical cure. However, it is often not given because of uncertainty over the risks of primaquine induced haemolysis when G6PD deficiency testing is unavailable. Recommended dosing of primaquine for radical cure in East Asia and Oceania is 0.5 mg base/kg/day and elsewhere is 0.25 mg base/kg/day. Alternative treatments are under investigation. Expert commentary: Geographic heterogeneity in relapse patterns and chloroquine susceptibility of P. vivax, and G6PD deficiency epidemiology mean that radical treatment should be given much more than it is today. G6PD testing should be made widely available so primaquine can be given more safely.
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Affiliation(s)
- Cindy S Chu
- a Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine , Mahidol University , Mae Sot , Thailand.,b Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine , Mahidol University , Bangkok , Thailand
| | - Nicholas J White
- b Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine , Mahidol University , Bangkok , Thailand.,c Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine , University of Oxford , Oxford , UK
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82
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Okami S, Kohtake N. Fine-Scale Mapping by Spatial Risk Distribution Modeling for Regional Malaria Endemicity and Its Implications under the Low-to-Moderate Transmission Setting in Western Cambodia. PLoS One 2016; 11:e0158737. [PMID: 27415623 PMCID: PMC4944927 DOI: 10.1371/journal.pone.0158737] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 06/21/2016] [Indexed: 11/18/2022] Open
Abstract
The disease burden of malaria has decreased as malaria elimination efforts progress. The mapping approach that uses spatial risk distribution modeling needs some adjustment and reinvestigation in accordance with situational changes. Here we applied a mathematical modeling approach for standardized morbidity ratio (SMR) calculated by annual parasite incidence using routinely aggregated surveillance reports, environmental data such as remote sensing data, and non-environmental anthropogenic data to create fine-scale spatial risk distribution maps of western Cambodia. Furthermore, we incorporated a combination of containment status indicators into the model to demonstrate spatial heterogeneities of the relationship between containment status and risks. The explanatory model was fitted to estimate the SMR of each area (adjusted Pearson correlation coefficient R2 = 0.774; Akaike information criterion AIC = 149.423). A Bayesian modeling framework was applied to estimate the uncertainty of the model and cross-scale predictions. Fine-scale maps were created by the spatial interpolation of estimated SMRs at each village. Compared with geocoded case data, corresponding predicted values showed conformity [Spearman’s rank correlation r = 0.662 in the inverse distance weighed interpolation and 0.645 in ordinal kriging (95% confidence intervals of 0.414–0.827 and 0.368–0.813, respectively), Welch’s t-test; Not significant]. The proposed approach successfully explained regional malaria risks and fine-scale risk maps were created under low-to-moderate malaria transmission settings where reinvestigations of existing risk modeling approaches were needed. Moreover, different representations of simulated outcomes of containment status indicators for respective areas provided useful insights for tailored interventional planning, considering regional malaria endemicity.
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Affiliation(s)
- Suguru Okami
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
- * E-mail:
| | - Naohiko Kohtake
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
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83
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Dwivedi A, Khim N, Reynes C, Ravel P, Ma L, Tichit M, Bourchier C, Kim S, Dourng D, Khean C, Chim P, Siv S, Frutos R, Lek D, Mercereau-Puijalon O, Ariey F, Menard D, Cornillot E. Plasmodium falciparum parasite population structure and gene flow associated to anti-malarial drugs resistance in Cambodia. Malar J 2016; 15:319. [PMID: 27301553 PMCID: PMC4908689 DOI: 10.1186/s12936-016-1370-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 06/02/2016] [Indexed: 11/25/2022] Open
Abstract
Background Western Cambodia is recognized as the epicentre of emergence of Plasmodium falciparum multi-drug resistance. The emergence of artemisinin resistance has been observed in this area since 2008–2009 and molecular signatures associated to artemisinin resistance have been characterized in k13 gene. At present, one of the major threats faced, is the possible spread of Asian artemisinin resistant parasites over the world threatening millions of people and jeopardizing malaria elimination programme efforts. To anticipate the diffusion of artemisinin resistance, the identification of the P. falciparum population structure and the gene flow among the parasite population in Cambodia are essential. Methods To this end, a mid-throughput PCR-LDR-FMA approach based on LUMINEX technology was developed to screen for genetic barcode in 533 blood samples collected in 2010–2011 from 16 health centres in malaria endemics areas in Cambodia. Results Based on successful typing of 282 samples, subpopulations were characterized along the borders of the country. Each 11-loci barcode provides evidence supporting allele distribution gradient related to subpopulations and gene flow. The 11-loci barcode successfully identifies recently emerging parasite subpopulations in western Cambodia that are associated with the C580Y dominant allele for artemisinin resistance in k13 gene. A subpopulation was identified in northern Cambodia that was associated to artemisinin (R539T resistant allele of k13 gene) and mefloquine resistance. Conclusions The gene flow between these subpopulations might have driven the spread of artemisinin resistance over Cambodia. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1370-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ankit Dwivedi
- Institut de Biologie Computationnelle (IBC), Montpellier, France.,IRCM-INSERM U1194, Institut de Recherche en Cancérologie de Montpellier, Montpellier, France.,Université de Montpellier, Montpellier, France.,ICM, Institut régional du Cancer Montpellier, Montpellier, France
| | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Christelle Reynes
- Laboratoire de Biostatistiques, Informatique et Physique Pharmaceutique, UFR Pharmacie, Université de Montpellier, Montpellier, France.,Institut de Génomique Fonctionnelle, Montpellier, France
| | - Patrice Ravel
- IRCM-INSERM U1194, Institut de Recherche en Cancérologie de Montpellier, Montpellier, France.,Université de Montpellier, Montpellier, France.,ICM, Institut régional du Cancer Montpellier, Montpellier, France
| | - Laurence Ma
- Genopole Sequencing Platform, Institut Pasteur, Paris, France
| | - Magali Tichit
- Genopole Sequencing Platform, Institut Pasteur, Paris, France
| | | | - Saorin Kim
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Dany Dourng
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Chanra Khean
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Pheaktra Chim
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Sovannaroth Siv
- National Centre for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Roger Frutos
- UMR 17, Intertryp, Cirad-IRD, Campus International de Baillarguet, Montpellier, France.,IES-UMR 5214, Institut d'Electronique et des Systèmes, Université de Montpellier-CNRS, Montpellier, France
| | - Dysoley Lek
- National Centre for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | | | - Frédéric Ariey
- Parasite Molecular Immunology Unit, Institut Pasteur, Paris, France
| | - Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia.
| | - Emmanuel Cornillot
- Institut de Biologie Computationnelle (IBC), Montpellier, France. .,IRCM-INSERM U1194, Institut de Recherche en Cancérologie de Montpellier, Montpellier, France. .,Université de Montpellier, Montpellier, France. .,ICM, Institut régional du Cancer Montpellier, Montpellier, France.
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84
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Tilley L, Straimer J, Gnädig NF, Ralph SA, Fidock DA. Artemisinin Action and Resistance in Plasmodium falciparum. Trends Parasitol 2016; 32:682-696. [PMID: 27289273 DOI: 10.1016/j.pt.2016.05.010] [Citation(s) in RCA: 206] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/10/2016] [Accepted: 05/13/2016] [Indexed: 12/16/2022]
Abstract
The worldwide use of artemisinin-based combination therapies (ACTs) has contributed in recent years to a substantial reduction in deaths resulting from Plasmodium falciparum malaria. Resistance to artemisinins, however, has emerged in Southeast Asia. Clinically, resistance is defined as a slower rate of parasite clearance in patients treated with an artemisinin derivative or an ACT. These slow clearance rates associate with enhanced survival rates of ring-stage parasites briefly exposed in vitro to dihydroartemisinin. We describe recent progress made in defining the molecular basis of artemisinin resistance, which has identified a primary role for the P. falciparum K13 protein. Using K13 mutations as molecular markers, epidemiological studies are now tracking the emergence and spread of artemisinin resistance. Mechanistic studies suggest potential ways to overcome resistance.
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Affiliation(s)
- Leann Tilley
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia.
| | - Judith Straimer
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Nina F Gnädig
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Stuart A Ralph
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA; Division of Infectious Diseases, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA.
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85
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Fairhurst RM, Dondorp AM. Artemisinin-Resistant Plasmodium falciparum Malaria. Microbiol Spectr 2016; 4:10.1128/microbiolspec.EI10-0013-2016. [PMID: 27337450 PMCID: PMC4992992 DOI: 10.1128/microbiolspec.ei10-0013-2016] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Indexed: 01/05/2023] Open
Abstract
For more than five decades, Southeast Asia (SEA) has been fertile ground for the emergence of drug-resistant Plasmodium falciparum malaria. After generating parasites resistant to chloroquine, sulfadoxine, pyrimethamine, quinine, and mefloquine, this region has now spawned parasites resistant to artemisinins, the world's most potent antimalarial drugs. In areas where artemisinin resistance is prevalent, artemisinin combination therapies (ACTs)-the first-line treatments for malaria-are failing fast. This worrisome development threatens to make malaria practically untreatable in SEA, and threatens to compromise global endeavors to eliminate this disease. A recent series of clinical, in vitro, genomics, and transcriptomics studies in SEA have defined in vivo and in vitro phenotypes of artemisinin resistance, identified its causal genetic determinant, explored its molecular mechanism, and assessed its clinical impact. Specifically, these studies have established that artemisinin resistance manifests as slow parasite clearance in patients and increased survival of early-ring-stage parasites in vitro; is caused by single nucleotide polymorphisms in the parasite's K13 gene, is associated with an upregulated "unfolded protein response" pathway that may antagonize the pro-oxidant activity of artemisinins, and selects for partner drug resistance that rapidly leads to ACT failures. In SEA, clinical studies are urgently needed to monitor ACT efficacy where K13 mutations are prevalent, test whether new combinations of currently available drugs cure ACT failures, and advance new antimalarial compounds through preclinical pipelines and into clinical trials. Intensifying these efforts should help to forestall the spread of artemisinin and partner drug resistance from SEA to sub-Saharan Africa, where the world's malaria transmission, morbidity, and mortality rates are highest.
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Affiliation(s)
- Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, United States of America
| | - Arjen M. Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
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86
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Abstract
For more than five decades, Southeast Asia (SEA) has been fertile ground for the emergence of drug-resistant Plasmodium falciparum malaria. After generating parasites resistant to chloroquine, sulfadoxine, pyrimethamine, quinine, and mefloquine, this region has now spawned parasites resistant to artemisinins, the world's most potent antimalarial drugs. In areas where artemisinin resistance is prevalent, artemisinin combination therapies (ACTs)-the first-line treatments for malaria-are failing fast. This worrisome development threatens to make malaria practically untreatable in SEA, and threatens to compromise global endeavors to eliminate this disease. A recent series of clinical, in vitro, genomics, and transcriptomics studies in SEA have defined in vivo and in vitro phenotypes of artemisinin resistance, identified its causal genetic determinant, explored its molecular mechanism, and assessed its clinical impact. Specifically, these studies have established that artemisinin resistance manifests as slow parasite clearance in patients and increased survival of early-ring-stage parasites in vitro; is caused by single nucleotide polymorphisms in the parasite's K13 gene, is associated with an upregulated "unfolded protein response" pathway that may antagonize the pro-oxidant activity of artemisinins, and selects for partner drug resistance that rapidly leads to ACT failures. In SEA, clinical studies are urgently needed to monitor ACT efficacy where K13 mutations are prevalent, test whether new combinations of currently available drugs cure ACT failures, and advance new antimalarial compounds through preclinical pipelines and into clinical trials. Intensifying these efforts should help to forestall the spread of artemisinin and partner drug resistance from SEA to sub-Saharan Africa, where the world's malaria transmission, morbidity, and mortality rates are highest.
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87
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Canavati SE, de Beyl CZ, Ly P, Shafique M, Boukheng T, Rang C, Whittaker MA, Roca-Feltrer A, Sintasath D. Evaluation of intensified behaviour change communication strategies in an artemisinin resistance setting. Malar J 2016; 15:249. [PMID: 27129496 PMCID: PMC4851777 DOI: 10.1186/s12936-016-1276-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 04/12/2016] [Indexed: 11/28/2022] Open
Abstract
Background In Cambodia, behaviour change communication (BCC) represents an integral component of malaria efforts aimed at fighting artemisinin resistant parasites and achieving elimination. The multi-pronged BCC interventions include interpersonal communication through village health volunteers (VHVs) and village malaria workers (VMWs), broadcasting malaria prevention, diagnosis and treatment messages via TV, radio and mobile broadcasting units (MBUs), distributing information education and communication (IEC) materials and introducing mobile malaria workers (MMWs) in endemic villages. Methods This was a cross sectional household survey using a stratified multi-stage cluster sampling approach, conducted in December 2012. A stratified multi-stage cluster sampling approach was used; 30 villages were selected (15 in each stratum) and a total of 774 households were interviewed. This survey aimed to assess the potential added effect of ‘intense’ BCC interventions in three Western provinces. Conducted 2 years after start of these efforts, ‘non-intense’ BCC (niBBC) interventions (e.g., radio or TV) were compared to “intense” BCC (iBBC) implemented through a set of interpersonal communication strategies such as VMWs, VHVs, mobile broadcasting units and listener viewer clubs. Results In both groups, the knowledge of the mode of malaria transmission was high (96.9 vs 97.2 %; p = 0.83), as well as of fever as a symptom (91.5 vs 93.5 %; p = 0.38). Knowledge of local risk factors, such as staying in the forest (39.7 vs 30.7 %; p = 0.17) or the farm (7.1 vs 5.1 %; p = 0.40) was low in both groups. Few respondents in either group knew that they must get tested if they suspected malaria (0.3 vs 0.1; p = 0.69). However, iBBC increased the discussions about malaria in the family (51.7 vs 35.8 %; p = 0.002) and reported prompt access to treatment in case of fever (77.1 vs 59.4 %; p < 0.01). Conclusion The use of iBCC supported positive improvements in both attitudes and behaviours among the population with regard to malaria compared to mass media (niBCC) only. The significantly increase in people seeking treatment for fever in iBCC villages supports Objective Five of the Strategic Plan in the Cambodia Malaria Elimination Action Framework (2016–2020). Therefore, this study provides evidence for the planning and implementation of future BCC interventions to achieve the elimination of artemisinin resistant Plasmodium falciparum malaria. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1276-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sara E Canavati
- Malaria Consortium Cambodia, Phnom Penh Office, House #91, St. 95, Boeung Trabek, Chamcar Morn, Phnom Penh, Cambodia.,Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand.,Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | - Celine Zegers de Beyl
- Malaria Consortium International, Development House, 56-64 Leonard Street, London, EC2A 4LT, UK
| | - Po Ly
- The National Center For Parasitology, Entomology and Malaria Control, Ministry of Health, Corner street 92, Trapaing Svay village, Sankat Phnom Penh Thmey, Khan Sensok, Phnom Penh, Cambodia
| | - Muhammad Shafique
- Malaria Consortium Asia, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajavidhi Road, Bangkok, 10400, Thailand.
| | - Thavrin Boukheng
- The National Center For Parasitology, Entomology and Malaria Control, Ministry of Health, Corner street 92, Trapaing Svay village, Sankat Phnom Penh Thmey, Khan Sensok, Phnom Penh, Cambodia
| | - Chandary Rang
- Malaria Consortium Cambodia, Phnom Penh Office, House #91, St. 95, Boeung Trabek, Chamcar Morn, Phnom Penh, Cambodia
| | - Maxine Anne Whittaker
- The University of Queensland, School of Public Health, Herston, QLD, 4006, Australia.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4006, Australia.,Division of Tropical Health and Medicine, James Cook University, Townsville, QLD 4006, Australia
| | - Arantxa Roca-Feltrer
- Malaria Consortium Asia, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajavidhi Road, Bangkok, 10400, Thailand
| | - David Sintasath
- Malaria Consortium Asia, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajavidhi Road, Bangkok, 10400, Thailand
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88
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History of malaria treatment as a predictor of subsequent subclinical parasitaemia: a cross-sectional survey and malaria case records from three villages in Pailin, western Cambodia. Malar J 2016; 15:240. [PMID: 27118311 PMCID: PMC4845326 DOI: 10.1186/s12936-016-1284-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 04/13/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Treatment of the sub-clinical reservoir of malaria, which may maintain transmission, could be an important component of elimination strategies. The reliable detection of asymptomatic infections with low levels of parasitaemia requires high-volume quantitative polymerase chain reaction (uPCR), which is impractical to conduct on a large scale. It is unknown to what extent sub-clinical parasitaemias originate from recent or older clinical episodes. This study explored the association between clinical history of malaria and subsequent sub-clinical parasitaemia. METHODS In June 2013 a cross-sectional survey was conducted in three villages in Pailin, western Cambodia. Demographic and epidemiological data and blood samples were collected. Blood was tested for malaria by high-volume qPCR. Positive samples were analysed by nested PCR to determine the Plasmodium species. To identify previous episodes of malaria, case records were collected from village malaria workers and local health facilities and linked to study participants. RESULTS Among 1343 participants, 40/122 (32.8 %) with a history of clinical malaria were parasitaemic during the cross-sectional survey, compared to 172/1221 (14.1 %) without this history (p < 0.001). Among the 212 parasitaemic participants in the survey, 40 (18.9 %) had a history of clinical malaria, compared to 87 out of 1131 (7.7 %) parasite-negative participants; p < 0.001, adjusted OR 3.3 (95 % CI; 2.1-5.1). A history of Plasmodium vivax was associated with sub-clinical P. vivax parasitaemia in the survey (p < 0.001), but this association was not seen with Plasmodium falciparum (p = 0.253); only three participants had both P. falciparum parasites in the survey and a clinical history of P. falciparum. CONCLUSIONS A clinical episode of vivax malaria was associated with subsequent sub-clinical parasitaemia. Treatment of P. vivax with artemisinin-based combination therapy without primaquine often resulted in recurrent episodes. Targeting individuals with a history of clinical malaria will be insufficient to eliminate the sub-clinical reservoir as they constitute a minority of parasitaemias.
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89
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Pasay CJ, Rockett R, Sekuloski S, Griffin P, Marquart L, Peatey C, Wang CYT, O'Rourke P, Elliott S, Baker M, Möhrle JJ, McCarthy JS. Piperaquine Monotherapy of Drug-Susceptible Plasmodium falciparum Infection Results in Rapid Clearance of Parasitemia but Is Followed by the Appearance of Gametocytemia. J Infect Dis 2016; 214:105-13. [PMID: 27056954 PMCID: PMC4907420 DOI: 10.1093/infdis/jiw128] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/24/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Piperaquine, coformulated with dihydroartemisinin, is a component of a widely used artemisinin combination therapy. There is a paucity of data on its antimalarial activity as a single agent. Such data, if available, would inform selection of new coformulations. METHODS We undertook a study in healthy subjects, using the induced blood stage malaria (IBSM) model to test the antimalarial activity of single doses of piperaquine (960, 640, and 480 mg) in 3 cohorts. In a pilot study in the third cohort, gametocyte clearance following administration of 15 mg, or 45 mg or no primaquine was investigated. RESULTS Parasite clearance over the 48-hour period after piperaquine administration was more rapid in the 960 mg cohort, compared with the 640 mg cohort (parasite reduction ratio, 2951 [95% confidence interval {CI}, 1520-5728] vs 586 [95% CI, 351-978]; P < .001). All 24 subjects developed gametocytemia as determined by pfs25 transcripts. Clearance of pfs25 was significantly faster in those receiving primaquine than in those not receiving primaquine (P < .001). CONCLUSIONS Piperaquine possesses rapid parasite-clearing activity, but monotherapy is followed by the appearance of gametocytemia, which could facilitate the spread of malaria. This new information should be taken into account when developing future antimalarial coformulations. CLINICAL TRIALS REGISTRATION ACTRN12613000565741.
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Affiliation(s)
| | - Rebecca Rockett
- School of Chemistry and Molecular Biosciences Queensland Pediatric Infectious Diseases Laboratory
| | | | - Paul Griffin
- QIMR Berghofer Medical Research Institute School of Medicine, University of Queensland Q-Pharm Department of Infectious Diseases, Mater Health Services and Mater Research Institute
| | | | | | | | | | | | | | | | - James S McCarthy
- QIMR Berghofer Medical Research Institute School of Medicine, University of Queensland Q-Pharm
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90
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[Multiple and successive treatment failures in a patient infected by Plasmodium falciparum in Cambodia and treated by dihydroartemisinin-piperaquine]. ACTA ACUST UNITED AC 2016; 109:87-90. [PMID: 27100863 DOI: 10.1007/s13149-016-0487-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
Cases of treatment failures following administration of artemisinin-based combination therapies (ACT) remain rare in malaria endemic areas. In Cambodia, however, failures of these treatments are now commonly observed. Usually, these post-treatment recurrences occur only once and a second course of the same treatment is sufficient to cure patients.We describe here an atypical case of a Plasmodium falciparum-infected patient manifesting several malaria recrudescence episodes following dihydroartemisinin-piperaquine (Eurartesim®) treatment. This case report illustrates the current issue of resistance to the latest generation of antimalarial drugs in Southeast Asia and highlights the difficulty in efficaciously fighting malaria in this region if new therapy remains unimplemented.
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91
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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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92
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Pulice G, Pelaz S, Matías-Hernández L. Molecular Farming in Artemisia annua, a Promising Approach to Improve Anti-malarial Drug Production. FRONTIERS IN PLANT SCIENCE 2016; 7:329. [PMID: 27047510 PMCID: PMC4796020 DOI: 10.3389/fpls.2016.00329] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 03/03/2016] [Indexed: 05/03/2023]
Abstract
Malaria is a parasite infection affecting millions of people worldwide. Even though progress has been made in prevention and treatment of the disease; an estimated 214 million cases of malaria occurred in 2015, resulting in 438,000 estimated deaths; most of them occurring in Africa among children under the age of five. This article aims to review the epidemiology, future risk factors and current treatments of malaria, with particular focus on the promising potential of molecular farming that uses metabolic engineering in plants as an effective anti-malarial solution. Malaria represents an example of how a health problem may, on one hand, influence the proper development of a country, due to its burden of the disease. On the other hand, it constitutes an opportunity for lucrative business of diverse stakeholders. In contrast, plant biofarming is proposed here as a sustainable, promising, alternative for the production, not only of natural herbal repellents for malaria prevention but also for the production of sustainable anti-malarial drugs, like artemisinin (AN), used for primary parasite infection treatments. AN, a sesquiterpene lactone, is a natural anti-malarial compound that can be found in Artemisia annua. However, the low concentration of AN in the plant makes this molecule relatively expensive and difficult to produce in order to meet the current worldwide demand of Artemisinin Combination Therapies (ACTs), especially for economically disadvantaged people in developing countries. The biosynthetic pathway of AN, a process that takes place only in glandular secretory trichomes of A. annua, is relatively well elucidated. Significant efforts have been made using plant genetic engineering to increase production of this compound. These include diverse genetic manipulation approaches, such as studies on diverse transcription factors which have been shown to regulate the AN genetic pathway and other biological processes. Results look promising; however, further efforts should be addressed toward optimization of the most cost-effective biofarming approaches for synthesis and production of medicines against the malaria parasite.
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Affiliation(s)
- Giuseppe Pulice
- Sequentia Biotech, Parc Científic de BarcelonaBarcelona, Spain
| | - Soraya Pelaz
- Plant Development and Signal Transduction Department, Centre for Research in Agricultural GenomicsBarcelona, Spain
- Institució Catalana de Recerca i Estudis AvançatsBarcelona, Spain
| | - Luis Matías-Hernández
- Sequentia Biotech, Parc Científic de BarcelonaBarcelona, Spain
- Plant Development and Signal Transduction Department, Centre for Research in Agricultural GenomicsBarcelona, Spain
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93
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Gotia HT, Munro JB, Knowles DP, Daubenberger CA, Bishop RP, Silva JC. Absolute Quantification of the Host-To-Parasite DNA Ratio in Theileria parva-Infected Lymphocyte Cell Lines. PLoS One 2016; 11:e0150401. [PMID: 26930209 PMCID: PMC4773007 DOI: 10.1371/journal.pone.0150401] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/12/2016] [Indexed: 11/18/2022] Open
Abstract
Theileria parva is a tick-transmitted intracellular apicomplexan pathogen of cattle in sub-Saharan Africa that causes East Coast fever (ECF). ECF is an acute fatal disease that kills over one million cattle annually, imposing a tremendous burden on African small-holder cattle farmers. The pathology and level of T. parva infections in its wildlife host, African buffalo (Syncerus caffer), and in cattle are distinct. We have developed an absolute quantification method based on quantitative PCR (qPCR) in which recombinant plasmids containing single copy genes specific to the parasite (apical membrane antigen 1 gene, ama1) or the host (hypoxanthine phosphoribosyltransferase 1, hprt1) are used as the quantification reference standards. Our study shows that T. parva and bovine cells are present in similar numbers in T. parva-infected lymphocyte cell lines and that consequently, due to its much smaller genome size, T. parva DNA comprises between 0.9% and 3% of the total DNA samples extracted from these lines. This absolute quantification assay of parasite and host genome copy number in a sample provides a simple and reliable method of assessing T. parva load in infected bovine lymphocytes, and is accurate over a wide range of host-to-parasite DNA ratios. Knowledge of the proportion of target DNA in a sample, as enabled by this method, is essential for efficient high-throughput genome sequencing applications for a variety of intracellular pathogens. This assay will also be very useful in future studies of interactions of distinct host-T. parva stocks and to fully characterize the dynamics of ECF infection in the field.
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Affiliation(s)
- Hanzel T. Gotia
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore Maryland, United States of America
| | - James B. Munro
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore Maryland, United States of America
| | - Donald P. Knowles
- Animal Disease Research Unit, Agricultural Research Service, US Department of Agriculture, Pullman, Washington, United States of America
- Department of Veterinary Microbiology & Pathology, Washington State University, Pullman, Maryland, United States of America
| | - Claudia A. Daubenberger
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - Richard P. Bishop
- International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore Maryland, United States of America
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore Maryland, United States of America
- * E-mail:
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94
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Abstract
PURPOSE OF REVIEW The emergence of artemisinin resistance in Southeast Asia (SEA), where artemisinin combination therapies (ACTs) are beginning to fail, threatens global endeavors to control and eliminate Plasmodium falciparum malaria. Future efforts to prevent the spread of this calamity to Africa will benefit from last year's tremendous progress in understanding artemisinin resistance. RECENT FINDINGS Multiple international collaborations have established that artemisinin resistance is associated with slow parasite clearance in patients, increased survival of early-ring-stage parasites in vitro, single-nucleotide polymorphisms (SNPs) in the parasite's kelch protein gene (K13), parasite 'founder' populations sharing a genetic background of four additional SNPs, parasite transcriptional profiles reflecting an 'unfolded protein response' and decelerated parasite development, and elevated parasite phosphatidylinositol-3-kinase activity. In Western Cambodia, where the K13 C580Y mutation is approaching fixation, the frontline ACT is failing to cure nearly half of patients, likely due to partner drug resistance. In Africa, where dozens of K13 mutations have been detected at low frequency, there is no evidence yet of artemisinin resistance. SUMMARY In SEA, clinical and epidemiological investigations are urgently needed to stop the further spread of artemisinin resistance, monitor the efficacy of ACTs where K13 mutations are prevalent, identify currently-available drug regimens that cure ACT failures, and rapidly advance new antimalarial compounds through preclinical studies and clinical trials.
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95
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Dihydroartemisinin-piperaquine resistance in Plasmodium falciparum malaria in Cambodia: a multisite prospective cohort study. THE LANCET. INFECTIOUS DISEASES 2016; 16:357-65. [PMID: 26774243 DOI: 10.1016/s1473-3099(15)00487-9] [Citation(s) in RCA: 352] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 11/17/2015] [Accepted: 11/19/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND Artemisinin resistance in Plasmodium falciparum threatens to reduce the efficacy of artemisinin combination therapies (ACTs), thus compromising global efforts to eliminate malaria. Recent treatment failures with dihydroartemisinin-piperaquine, the current first-line ACT in Cambodia, suggest that piperaquine resistance may be emerging in this country. We explored the relation between artemisinin resistance and dihydroartemisinin-piperaquine failures, and sought to confirm the presence of piperaquine-resistant P falciparum infections in Cambodia. METHODS In this prospective cohort study, we enrolled patients aged 2-65 years with uncomplicated P falciparum malaria in three Cambodian provinces: Pursat, Preah Vihear, and Ratanakiri. Participants were given standard 3-day courses of dihydroartemisinin-piperaquine. Peripheral blood parasite densities were measured until parasites cleared and then weekly to 63 days. The primary outcome was recrudescent P falciparum parasitaemia within 63 days. We measured piperaquine plasma concentrations at baseline, 7 days, and day of recrudescence. We assessed phenotypic and genotypic markers of drug resistance in parasite isolates. The study is registered with ClinicalTrials.gov, number NCT01736319. FINDINGS Between Sept 4, 2012, and Dec 31, 2013, we enrolled 241 participants. In Pursat, where artemisinin resistance is entrenched, 37 (46%) of 81 patients had parasite recrudescence. In Preah Vihear, where artemisinin resistance is emerging, ten (16%) of 63 patients had recrudescence and in Ratanakiri, where artemisinin resistance is rare, one (2%) of 60 patients did. Patients with recrudescent P falciparum infections were more likely to have detectable piperaquine plasma concentrations at baseline compared with non-recrudescent patients, but did not differ significantly in age, initial parasite density, or piperaquine plasma concentrations at 7 days. Recrudescent parasites had a higher prevalence of kelch13 mutations, higher piperaquine 50% inhibitory concentration (IC50) values, and lower mefloquine IC50 values; none had multiple pfmdr1 copies, a genetic marker of mefloquine resistance. INTERPRETATION Dihydroartemisinin-piperaquine failures are caused by both artemisinin and piperaquine resistance, and commonly occur in places where dihydroartemisinin-piperaquine has been used in the private sector. In Cambodia, artesunate plus mefloquine may be a viable option to treat dihydroartemisinin-piperaquine failures, and a more effective first-line ACT in areas where dihydroartemisinin-piperaquine failures are common. The use of single low-dose primaquine to eliminate circulating gametocytes is needed in areas where artemisinin and ACT resistance is prevalent. FUNDING National Institute of Allergy and Infectious Diseases.
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Slater HC, Griffin JT, Ghani AC, Okell LC. Assessing the potential impact of artemisinin and partner drug resistance in sub-Saharan Africa. Malar J 2016; 15:10. [PMID: 26739092 PMCID: PMC4704433 DOI: 10.1186/s12936-015-1075-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 12/23/2015] [Indexed: 12/26/2022] Open
Abstract
Background Artemisinin and partner drug resistant malaria parasites have emerged in Southeast Asia. If resistance were to emerge in Africa it could have a devastating impact on malaria-related morbidity and mortality. This study estimates the potential impact of artemisinin and partner drug resistance on disease burden in Africa if it were to emerge. Methods Using data from Asia and Africa, five possible artemisinin and partner drug resistance scenarios are characterized. An individual-based malaria transmission model is used to estimate the impact of each resistance scenario on clinical incidence and parasite prevalence across Africa. Artemisinin resistance is characterized by slow parasite clearance and partner drug resistance is associated with late clinical failure or late parasitological failure. Results Scenarios with high levels of recrudescent infections resulted in far greater increases in clinical incidence compared to scenarios with high levels of slow parasite clearance. Across Africa, it is estimated that artemisinin and partner drug resistance at levels similar to those observed in Oddar Meanchey province in Cambodia could result in an additional 78 million cases over a 5 year period, a 7 % increase in cases compared to a scenario with no resistance. A scenario with high levels of slow clearance but no recrudescence resulted in an additional 10 million additional cases over the same period. Conclusion Artemisinin resistance is potentially a more pressing concern than partner drug resistance due to the lack of viable alternatives. However, it is predicted that a failing partner drug will result in greater increases in malaria cases and morbidity than would be observed from artemisinin resistance only. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-1075-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hannah C Slater
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, W2 1PG, UK.
| | - Jamie T Griffin
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, W2 1PG, UK.
| | - Azra C Ghani
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, W2 1PG, UK.
| | - Lucy C Okell
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, W2 1PG, UK.
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Duru V, Khim N, Leang R, Kim S, Domergue A, Kloeung N, Ke S, Chy S, Eam R, Khean C, Loch K, Ken M, Lek D, Beghain J, Ariey F, Guerin PJ, Huy R, Mercereau-Puijalon O, Witkowski B, Menard D. Plasmodium falciparum dihydroartemisinin-piperaquine failures in Cambodia are associated with mutant K13 parasites presenting high survival rates in novel piperaquine in vitro assays: retrospective and prospective investigations. BMC Med 2015; 13:305. [PMID: 26695060 PMCID: PMC4688949 DOI: 10.1186/s12916-015-0539-5] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 11/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The declining efficacy of dihydroartemisinin-piperaquine against Plasmodium falciparum in Cambodia, along with increasing numbers of recrudescent cases, suggests resistance to both artemisinin and piperaquine. Available in vitro piperaquine susceptibility assays do not correlate with treatment outcome. A novel assay using a pharmacologically relevant piperaquine dose/time exposure was designed and its relevance explored in retrospective and prospective studies. METHODS The piperaquine survival assay (PSA) exposed parasites to 200 nM piperaquine for 48 hours and monitored survival 24 hours later. The retrospective study tested 32 culture-adapted, C580Y-K13 mutant parasites collected at enrolment from patients treated with a 3-day course of dihydroartemisinin-piperaquine and having presented or not with a recrudescence at day 42 (registered ACTRN12615000793516). The prospective study assessed ex vivo PSA survival rate alongside K13 polymorphism of isolates collected from patients enrolled in an open-label study with dihydroartemisinin-piperaquine for uncomplicated P. falciparum malaria in Cambodia (registered ACTRN12615000696594). RESULTS All parasites from recrudescent cases had in vitro or ex vivo PSA survival rates ≥10%, a relevant cut-off value for piperaquine-resistance. Ex vivo PSA survival rates were higher for recrudescent than non-recrudescent cases (39.2% vs. 0.17%, P <1 × 10(-7)). Artemisinin-resistant K13 mutants with ex vivo PSA survival rates ≥10% were associated with 32-fold higher risk of recrudescence (95% CI, 4.5-224; P = 0.0005). CONCLUSION PSA adequately captures the piperaquine resistance/recrudescence phenotype, a mainstay to identify molecular marker(s) and evaluate efficacy of alternative drugs. Combined ex vivo PSA and K13 genotyping provides a convenient monitor for both artemisinin and piperaquine resistance where dihydroartemisinin-piperaquine is used.
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Affiliation(s)
- Valentine Duru
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Rithea Leang
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia.
| | - Saorin Kim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Anais Domergue
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Nimol Kloeung
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Sopheakvatey Ke
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Sophy Chy
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Rotha Eam
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Chanra Khean
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Kaknika Loch
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Malen Ken
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia.
| | - Johann Beghain
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France.
| | - Frédéric Ariey
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France.
| | - Philippe J Guerin
- WorldWide Antimalarial Resistance Network, Oxford, UK. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK.
| | - Rekol Huy
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia.
| | | | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
| | - Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, BP 983, Phnom Penh, Cambodia.
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Phyo AP, Jittamala P, Nosten FH, Pukrittayakamee S, Imwong M, White NJ, Duparc S, Macintyre F, Baker M, Möhrle JJ. Antimalarial activity of artefenomel (OZ439), a novel synthetic antimalarial endoperoxide, in patients with Plasmodium falciparum and Plasmodium vivax malaria: an open-label phase 2 trial. THE LANCET. INFECTIOUS DISEASES 2015; 16:61-69. [PMID: 26448141 PMCID: PMC4700386 DOI: 10.1016/s1473-3099(15)00320-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 08/31/2015] [Accepted: 09/03/2015] [Indexed: 11/28/2022]
Abstract
Background Artefenomel (OZ439) is a novel synthetic trioxolane with improved pharmacokinetic properties compared with other antimalarial drugs with the artemisinin pharmacophore. Artefenomel has been generally well tolerated in volunteers at doses up to 1600 mg and is being developed as a partner drug in an antimalarial combination treatment. We investigated the efficacy, tolerability, and pharmacokinetics of artefenomel at different doses in patients with Plasmodium falciparum or Plasmodium vivax malaria. Methods This phase 2a exploratory, open-label trial was done at the Hospital for Tropical Diseases, Bangkok, and the Shoklo Malaria Research Unit in Thailand. Adult patients with acute, uncomplicated P falciparum or P vivax malaria received artefenomel in a single oral dose (200 mg, 400 mg, 800 mg, or 1200 mg). The first cohort received 800 mg. Testing of a new dose of artefenomel in a patient cohort was decided on after safety and efficacy assessment of the preceding cohort. The primary endpoint was the natural log parasite reduction per 24 h. Definitive oral treatment was given at 36 h. This trial is registered with ClinicalTrials.gov, number NCT01213966. Findings Between Oct 24, 2010, and May 25, 2012, 82 patients were enrolled (20 in each of the 200 mg, 400 mg, and 800 mg cohorts, and 21 in the 1200 mg cohort). One patient withdrew consent (before the administration of artefenomel) but there were no further dropouts. The parasite reduction rates per 24 h ranged from 0·90 to 1·88 for P falciparum, and 2·09 to 2·53 for P vivax. All doses were equally effective in both P falciparum and P vivax malaria, with median parasite clearance half-lives of 4·1 h (range 1·3–6·7) to 5·6 h (2·0–8·5) for P falciparum and 2·3 h (1·2–3·9) to 3·2 h (0·9–15·0) for P vivax. Maximum plasma concentrations, dose-proportional to 800 mg, occurred at 4 h (median). The estimated elimination half-life was 46–62 h. No serious drug-related adverse effects were reported; other adverse effects were generally mild and reversible, with the highest number in the 1200 mg cohort (17 [81%] patients with at least one adverse event). The most frequently reported adverse effect was an asymptomatic increase in plasma creatine phosphokinase concentration (200 mg, n=5; 400 mg, n=3; 800 mg, n=1; 1200 mg, n=3). Interpretation Artefenomel is a new synthetic antimalarial peroxide with a good safety profile that clears parasitaemia rapidly in both P falciparum and P vivax malaria. Its long half-life suggests a possible use in a single-dose treatment in combination with other drugs. Funding Bill & Melinda Gates Foundation, Wellcome Trust, and UK Department for International Development.
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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; Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Podjanee Jittamala
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - François H Nosten
- 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; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sasithon Pukrittayakamee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | | | - Mark Baker
- Medicines for Malaria Venture, Geneva, Switzerland
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Dahal P, d'Alessandro U, Dorsey G, Guerin PJ, Nsanzabana C, Price RN, Sibley CH, Stepniewska K, Talisuna AO. Clinical determinants of early parasitological response to ACTs in African patients with uncomplicated falciparum malaria: a literature review and meta-analysis of individual patient data. BMC Med 2015; 13:212. [PMID: 26343145 PMCID: PMC4561425 DOI: 10.1186/s12916-015-0445-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/11/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Artemisinin-resistant Plasmodium falciparum has emerged in the Greater Mekong sub-region and poses a major global public health threat. Slow parasite clearance is a key clinical manifestation of reduced susceptibility to artemisinin. This study was designed to establish the baseline values for clearance in patients from Sub-Saharan African countries with uncomplicated malaria treated with artemisinin-based combination therapies (ACTs). METHODS A literature review in PubMed was conducted in March 2013 to identify all prospective clinical trials (uncontrolled trials, controlled trials and randomized controlled trials), including ACTs conducted in Sub-Saharan Africa, between 1960 and 2012. Individual patient data from these studies were shared with the WorldWide Antimalarial Resistance Network (WWARN) and pooled using an a priori statistical analytical plan. Factors affecting early parasitological response were investigated using logistic regression with study sites fitted as a random effect. The risk of bias in included studies was evaluated based on study design, methodology and missing data. RESULTS In total, 29,493 patients from 84 clinical trials were included in the analysis, treated with artemether-lumefantrine (n = 13,664), artesunate-amodiaquine (n = 11,337) and dihydroartemisinin-piperaquine (n = 4,492). The overall parasite clearance rate was rapid. The parasite positivity rate (PPR) decreased from 59.7 % (95 % CI: 54.5-64.9) on day 1 to 6.7 % (95 % CI: 4.8-8.7) on day 2 and 0.9 % (95 % CI: 0.5-1.2) on day 3. The 95th percentile of observed day 3 PPR was 5.3 %. Independent risk factors predictive of day 3 positivity were: high baseline parasitaemia (adjusted odds ratio (AOR) = 1.16 (95 % CI: 1.08-1.25); per 2-fold increase in parasite density, P <0.001); fever (>37.5 °C) (AOR = 1.50 (95 % CI: 1.06-2.13), P = 0.022); severe anaemia (AOR = 2.04 (95 % CI: 1.21-3.44), P = 0.008); areas of low/moderate transmission setting (AOR = 2.71 (95 % CI: 1.38-5.36), P = 0.004); and treatment with the loose formulation of artesunate-amodiaquine (AOR = 2.27 (95 % CI: 1.14-4.51), P = 0.020, compared to dihydroartemisinin-piperaquine). CONCLUSIONS The three ACTs assessed in this analysis continue to achieve rapid early parasitological clearance across the sites assessed in Sub-Saharan Africa. A threshold of 5 % day 3 parasite positivity from a minimum sample size of 50 patients provides a more sensitive benchmark in Sub-Saharan Africa compared to the current recommended threshold of 10 % to trigger further investigation of artemisinin susceptibility.
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Affiliation(s)
| | - Prabin Dahal
- WorldWide Antimalarial Resistance Network (WWARN); Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, UK
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Fairhurst RM. High Antimalarial Efficacy of Dihydroartemisinin-Piperaquine on the China-Myanmar Border: The Calm Before the Storm. Am J Trop Med Hyg 2015; 93:436-437. [PMID: 26283745 PMCID: PMC4559676 DOI: 10.4269/ajtmh.15-0349] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 05/11/2015] [Indexed: 11/29/2022] Open
Affiliation(s)
- Rick M. Fairhurst
- *Address correspondence to Rick M. Fairhurst, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Room 3E-10A, Rockville, MD 20852. E-mail:
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