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Annamalai Subramani P, Tipthara P, Kolli SK, Nicholas J, Barnes SJ, Ogbondah MM, Kobylinski KC, Tarning J, Adams JH. Efficacy of ivermectin and its metabolites against Plasmodium falciparum liver stages in primary human hepatocytes. Antimicrob Agents Chemother 2024:e0127223. [PMID: 38904389 DOI: 10.1128/aac.01272-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 06/01/2024] [Indexed: 06/22/2024] Open
Abstract
Ivermectin, a broad-spectrum anti-parasitic drug, has been proposed as a novel vector control tool to reduce malaria transmission by mass drug administration. Ivermectin and some metabolites have mosquito-lethal effect, reducing Anopheles mosquito survival. Ivermectin inhibits liver stage development in a rodent malaria model, but no inhibition was observed in a primate malaria model or in a human malaria challenge trial. In the liver, cytochrome P450 3A4 and 3A5 enzymes metabolize ivermectin, which may impact drug efficacy. Thus, understanding ivermectin metabolism and assessing this impact on Plasmodium liver stage development is critical. Using primary human hepatocytes (PHHs), we characterized ivermectin metabolism and evaluated the efficacy of ivermectin and its primary metabolites M1 (3″-O-demethyl ivermectin) and M3 (4-hydroxymethyl ivermectin) against Plasmodium falciparum liver stages. Two different modes of ivermectin exposure were evaluated: prophylactic mode (days 0-3 post-infection) and curative mode (days 3-5 post-infection). We used two different PHH donors and modes to determine the inhibitory concentration (IC50) of ivermectin, M1, M3, and the known anti-malarial drug pyrimethamine, with IC50 values ranging from 1.391 to 14.44, 9.95-23.71, 4.767-8.384, and 0.9073-5.416 µM, respectively. In our PHH model, ivermectin and metabolites M1 and M3 demonstrated inhibitory activity against P. falciparum liver stages in curative treatment mode (days 3-5) and marginal activity in prophylactic treatment mode (days 0-3). Ivermectin had improved efficacy when co-administered with ketoconazole, a specific inhibitor of cytochrome P450 3A4 enzyme. Further studies should be performed to examine ivermectin liver stage efficacy when co-administered with CYP3A4 inhibitors and anti-malarial drugs to understand the pharmacokinetic and pharmacodynamic drug-drug interactions that enhance efficacy against human malaria parasites in vitro.
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Affiliation(s)
- Pradeep Annamalai Subramani
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Phornpimon Tipthara
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Surendra Kumar Kolli
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Justin Nicholas
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, USA
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Samantha J Barnes
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Madison M Ogbondah
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Kevin C Kobylinski
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - John H Adams
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, USA
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Vanachayangkul P, Kodchakorn C, Ta-Aksorn W, Im-Erbsin R, Tungtaeng A, Tipthara P, Tarning J, Lugo-Roman LA, Wojnarski M, Vesely BA, Kobylinski KC. Safety, pharmacokinetics, and potential neurological interactions of ivermectin, tafenoquine, and chloroquine in Rhesus macaques. Antimicrob Agents Chemother 2024:e0018124. [PMID: 38742896 DOI: 10.1128/aac.00181-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/19/2024] [Indexed: 05/16/2024] Open
Abstract
Ivermectin (IVM) could be used for malaria control as treated individuals are lethal to blood-feeding Anopheles, resulting in reduced transmission. Tafenoquine (TQ) is used to clear the liver reservoir of Plasmodium vivax and as a prophylactic treatment in high-risk populations. It has been suggested to use ivermectin and tafenoquine in combination, but the safety of these drugs in combination has not been evaluated. Early derivatives of 8-aminoquinolones (8-AQ) were neurotoxic, and ivermectin is an inhibitor of the P-glycoprotein (P-gp) blood brain barrier (BBB) transporter. Thus, there is concern that co-administration of these drugs could be neurotoxic. This study aimed to evaluate the safety and pharmacokinetic interaction of tafenoquine, ivermectin, and chloroquine (CQ) in Rhesus macaques. No clinical, biochemistry, or hematological outcomes of concern were observed. The Cambridge Neuropsychological Test Automated Battery (CANTAB) was employed to assess potential neurological deficits following drug administration. Some impairment was observed with tafenoquine alone and in the same monkeys with subsequent co-administrations. Co-administration of chloroquine and tafenoquine resulted in increased plasma exposure to tafenoquine. Urine concentrations of the 5,6 orthoquinone TQ metabolite were increased with co-administration of tafenoquine and ivermectin. There was an increase in ivermectin plasma exposure when co-administered with chloroquine. No interaction of tafenoquine on ivermectin was observed in vitro. Chloroquine and trace levels of ivermectin, but not tafenoquine, were observed in the cerebrospinal fluid. The 3''-O-demethyl ivermectin metabolite was observed in macaque plasma but not in urine or cerebrospinal fluid. Overall, the combination of ivermectin, tafenoquine, and chloroquine did not have clinical, neurological, or pharmacological interactions of concern in macaques; therefore, this combination could be considered for evaluation in human trials.
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Affiliation(s)
- Pattaraporn Vanachayangkul
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chanikarn Kodchakorn
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Winita Ta-Aksorn
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Rawiwan Im-Erbsin
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Anchalee Tungtaeng
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Phornpimon Tipthara
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Luis A Lugo-Roman
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Mariusz Wojnarski
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Brian A Vesely
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Kevin C Kobylinski
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
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Blessborn D, Kaewkhao N, Tarning J. A high-throughput LC-MS/MS assay for piperaquine from dried blood spots: Improving malaria treatment in resource-limited settings. J Mass Spectrom Adv Clin Lab 2024; 31:19-26. [PMID: 38229676 PMCID: PMC10789632 DOI: 10.1016/j.jmsacl.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 12/04/2023] [Accepted: 12/21/2023] [Indexed: 01/18/2024] Open
Abstract
Background Malaria is a parasitic disease that affects many of the poorest economies, resulting in approximately 241 million clinical episodes and 627,000 deaths annually. Piperaquine, when administered with dihydroartemisinin, is an effective drug against the disease. Drug concentration measurements taken on day 7 after treatment initiation have been shown to be a good predictor of therapeutic success with piperaquine. A simple capillary blood collection technique, where blood is dried onto filter paper, is especially suitable for drug studies in remote areas or resource-limited settings or when taking samples from children, toddlers, and infants. Methods Three 3.2 mm discs were punched out from a dried blood spot (DBS) and then extracted in a 96-well plate using solid phase extraction on a fully automated liquid handling system. The analysis was performed using LC-MS/MS with a calibration range of 3 - 1000 ng/mL. Results The recovery rate was approximately 54-72 %, and the relative standard deviation was below 9 % for low, middle and high quality control levels. The LC-MS/MS quantification limit of 3 ng/mL is sensitive enough to detect piperaquine for up to 4-8 weeks after drug administration, which is crucial when evaluating recrudescence and drug resistance development. While different hematocrit levels can affect DBS drug measurements, the effect was minimal for piperaquine. Conclusion A sensitive LC-MS/MS method, in combination with fully automated extraction in a 96-well plate format, was developed and validated for the quantification of piperaquine in DBS. The assay was implemented in a bioanalytical laboratory for processing large-scale clinical trial samples.
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Affiliation(s)
- Daniel Blessborn
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Natpapat Kaewkhao
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
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Chen I, Doum D, Mannion K, Hustedt J, Sovannaroth S, McIver D, Macdonald M, Lobo N, Tatarsky A, Handley MA, Neukom J. Applying the COM-B behaviour change model to a pilot study delivering volatile pyrethroid spatial repellents and insecticide-treated clothing to forest-exposed populations in Mondulkiri Province, Cambodia. Malar J 2023; 22:251. [PMID: 37658337 PMCID: PMC10472618 DOI: 10.1186/s12936-023-04685-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 09/03/2023] Open
Abstract
BACKGROUND Southeast Asia is making tremendous progress towards their 2030 malaria elimination goal but needs new interventions to stop forest malaria. This study trials two new vector control tools, a volatile pyrethroid spatial repellent (VPSR) and insecticide-treated clothing (ITC), amongst forest-exposed populations in Mondulkiri Province Cambodia to inform their potential use for eliminating forest malaria. METHODS 21 forest-exposed individuals were given a questionnaire on their perceptions of malaria and preventive practices used, after which they trialed two products sequentially. Clothes was treated with ITC by the study team. Mixed methods were used to understand their experience, attitudes, and preferences regarding the products trialed. Quantitative data was summarized and qualitative insights were analysed using thematic analysis, applying the Capability, Opportunity, and Motivation Behaviour Change (COM-B) model and Behaviour Change Wheel Framework to identify intervention functions to support tailored product rollout amongst these populations. RESULTS Study participants reported a need for protection from mosquito bites in outdoor and forest-exposed settings and perceived both products trialed to be effective for this purpose. The VPSR product was preferred when travel was not required, whereas ITC was preferred for ease of use when going to the forest, especially in rainy conditions. COM-B analysis identified that key enablers for use of both products included their perceived efficacy and ease of use, which required no skill or preparation. For barriers to use, the odour of ITC was sometimes perceived as being toxic, as well as its inability to protect uncovered skin from mosquito bites, while the perceived usefulness of the VPSR product trialed was limited by its water sensitivity in rainy forest settings. Intervention components to encourage appropriate and sustained use of these products include education about how to use these products and what to expect, persuasion to use them from community leaders and targeted channels, and enablement to facilitate convenient and affordable access. CONCLUSION The rollout of VPSRs and ITC amongst forest-exposed populations can be useful for eliminating malaria in Southeast Asia. Study findings can be applied to increase product uptake among forest exposed populations in Cambodia, while manufacturers can aim to develop products that are rainproof, easy to use in forest settings, and have favourable odour profiles to target users.
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Affiliation(s)
- Ingrid Chen
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA.
| | - Dyna Doum
- Health Forefront Organization, Phnom Penh, Cambodia
| | - Kylie Mannion
- Menzies School of Health Research, Charles Darwin University, Casuarina, Australia
| | - John Hustedt
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - David McIver
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | | | - Neil Lobo
- University of Notre Dame, Notre Dame, IN, USA
| | - Allison Tatarsky
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Margaret A Handley
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Josselyn Neukom
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
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Yipsirimetee A, Tipthara P, Hanboonkunupakarn B, Tripura R, Lek D, Kümpornsin K, Lee MCS, Sattabongkot J, Dondorp AM, White NJ, Kobylinski KC, Tarning J, Chotivanich K. Activity of Ivermectin and Its Metabolites against Asexual Blood Stage Plasmodium falciparum and Its Interactions with Antimalarial Drugs. Antimicrob Agents Chemother 2023; 67:e0173022. [PMID: 37338381 PMCID: PMC10368210 DOI: 10.1128/aac.01730-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 05/12/2023] [Indexed: 06/21/2023] Open
Abstract
Ivermectin is an endectocide used widely to treat a variety of internal and external parasites. Field trials of ivermectin mass drug administration for malaria transmission control have demonstrated a reduction of Anopheles mosquito survival and human malaria incidence. Ivermectin will mostly be deployed together with artemisinin-based combination therapies (ACT), the first-line treatment of falciparum malaria. It has not been well established if ivermectin has activity against asexual stage Plasmodium falciparum or if it interacts with the parasiticidal activity of other antimalarial drugs. This study evaluated antimalarial activity of ivermectin and its metabolites in artemisinin-sensitive and artemisinin-resistant P. falciparum isolates and assessed in vitro drug-drug interaction with artemisinins and its partner drugs. The concentration of ivermectin causing half of the maximum inhibitory activity (IC50) on parasite survival was 0.81 μM with no significant difference between artemisinin-sensitive and artemisinin-resistant isolates (P = 0.574). The ivermectin metabolites were 2-fold to 4-fold less active than the ivermectin parent compound (P < 0.001). Potential pharmacodynamic drug-drug interactions of ivermectin with artemisinins, ACT-partner drugs, and atovaquone were studied in vitro using mixture assays providing isobolograms and derived fractional inhibitory concentrations. There were no synergistic or antagonistic pharmacodynamic interactions when combining ivermectin and antimalarial drugs. In conclusion, ivermectin does not have clinically relevant activity against the asexual blood stages of P. falciparum. It also does not affect the in vitro antimalarial activity of artemisinins or ACT-partner drugs against asexual blood stages of P. falciparum.
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Affiliation(s)
- Achaporn Yipsirimetee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Phornpimon Tipthara
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Borimas Hanboonkunupakarn
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rupam Tripura
- 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, United Kingdom
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Krittikorn Kümpornsin
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
- Calibr, Division of the Scripps Research Institute, La Jolla, California, USA
| | - Marcus C. S. Lee
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - 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, United Kingdom
| | - Nicholas J. White
- 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, United Kingdom
| | - Kevin C. Kobylinski
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Joel Tarning
- 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, United Kingdom
| | - Kesinee Chotivanich
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Hutchins H, Bradley J, Pretorius E, Teixeira da Silva E, Vasileva H, Jones RT, Ndiath MO, Dit Massire Soumare H, Mabey D, Nante EJ, Martins C, Logan JG, Slater H, Drakeley C, D'Alessandro U, Rodrigues A, Last AR. Protocol for a cluster randomised placebo-controlled trial of adjunctive ivermectin mass drug administration for malaria control on the Bijagós Archipelago of Guinea-Bissau: the MATAMAL trial. BMJ Open 2023; 13:e072347. [PMID: 37419638 PMCID: PMC10335573 DOI: 10.1136/bmjopen-2023-072347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 06/20/2023] [Indexed: 07/09/2023] Open
Abstract
INTRODUCTION As malaria declines, innovative tools are required to further reduce transmission and achieve elimination. Mass drug administration (MDA) of artemisinin-based combination therapy (ACT) is capable of reducing malaria transmission where coverage of control interventions is already high, though the impact is short-lived. Combining ACT with ivermectin, an oral endectocide shown to reduce vector survival, may increase its impact, while also treating ivermectin-sensitive co-endemic diseases and minimising the potential impact of ACT resistance in this context. METHODS AND ANALYSIS MATAMAL is a cluster-randomised placebo-controlled trial. The trial is being conducted in 24 clusters on the Bijagós Archipelago, Guinea-Bissau, where the peak prevalence of Plasmodium falciparum (Pf) parasitaemia is approximately 15%. Clusters have been randomly allocated to receive MDA with dihydroartemisinin-piperaquine and either ivermectin or placebo. The primary objective is to determine whether the addition of ivermectin MDA is more effective than dihydroartemisinin-piperaquine MDA alone in reducing the prevalence of P. falciparum parasitaemia, measured during peak transmission season after 2 years of seasonal MDA. Secondary objectives include assessing prevalence after 1 year of MDA; malaria incidence monitored through active and passive surveillance; age-adjusted prevalence of serological markers indicating exposure to P. falciparum and anopheline mosquitoes; vector parous rates, species composition, population density and sporozoite rates; prevalence of vector pyrethroid resistance; prevalence of artemisinin resistance in P. falciparum using genomic markers; ivermectin's impact on co-endemic diseases; coverage estimates; and the safety of combined MDA. ETHICS AND DISSEMINATION The trial has been approved by the London School of Hygiene and Tropical Medicine's Ethics Committee (UK) (19156) and the Comite Nacional de Eticas de Saude (Guinea-Bissau) (084/CNES/INASA/2020). Results will be disseminated in peer-reviewed publications and in discussion with the Bissau-Guinean Ministry of Public Health and participating communities. TRIAL REGISTRATION NUMBER NCT04844905.
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Affiliation(s)
- Harry Hutchins
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - John Bradley
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Elizabeth Pretorius
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Eunice Teixeira da Silva
- Projecto de Saúde Bandim, Bissau, Guinea-Bissau
- Ministério de Saúde Pública, Bissau, Guinea-Bissau
| | - Hristina Vasileva
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Robert T Jones
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - David Mabey
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Ernesto Jose Nante
- Programa Nacional de Luta Contra o Paludismo, Ministério de Saúde, Bissau, Guinea-Bissau
| | | | - James G Logan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
- Arctech Innovation, London, UK
| | | | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Amabelia Rodrigues
- Projecto de Saúde Bandim, Bissau, Guinea-Bissau
- Ministério de Saúde Pública, Bissau, Guinea-Bissau
| | - Anna R Last
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
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Kern C, Müller P, Chaccour C, Liechti ME, Hammann F, Duthaler U. Pharmacokinetics of ivermectin metabolites and their activity against Anopheles stephensi mosquitoes. Malar J 2023; 22:194. [PMID: 37355605 DOI: 10.1186/s12936-023-04624-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 06/16/2023] [Indexed: 06/26/2023] Open
Abstract
BACKGROUND Ivermectin (22,23-dihydroavermectin B1a: H2B1a) is an endectocide used to treat worm infections and ectoparasites including lice and scabies mites. Furthermore, survival of malaria transmitting Anopheles mosquitoes is strongly decreased after feeding on humans recently treated with ivermectin. Currently, mass drug administration of ivermectin is under investigation as a potential novel malaria vector control tool to reduce Plasmodium transmission by mosquitoes. A "post-ivermectin effect" has also been reported, in which the survival of mosquitoes remains reduced even after ivermectin is no longer detectable in blood meals. In the present study, existing material from human clinical trials was analysed to understand the pharmacokinetics of ivermectin metabolites and feeding experiments were performed in Anopheles stephensi mosquitoes to assess whether ivermectin metabolites contribute to the mosquitocidal action of ivermectin and whether they may be responsible for the post-ivermectin effect. METHODS Ivermectin was incubated in the presence of recombinant human cytochrome P450 3A4/5 (CYP 3A4/5) to produce ivermectin metabolites. In total, nine metabolites were purified by semi-preparative high-pressure liquid chromatography. The pharmacokinetics of the metabolites were assessed over three days in twelve healthy volunteers who received a single oral dose of 12 mg ivermectin. Blank whole blood was spiked with the isolated metabolites at levels matching the maximal blood concentration (Cmax) observed in pharmacokinetics study samples. These samples were fed to An. stephensi mosquitoes, and their survival and vitality was recorded daily over 3 days. RESULTS Human CYP3A4 metabolised ivermectin more rapidly than CYP3A5. Ivermectin metabolites M1-M8 were predominantly formed by CYP3A4, whereas metabolite M9 (hydroxy-H2B1a) was mainly produced by CYP3A5. Both desmethyl-H2B1a (M1) and hydroxy-H2B1a (M2) killed all mosquitoes within three days post-feeding, while administration of desmethyl, hydroxy-H2B1a (M4) reduced survival to 35% over an observation period of 3 days. Ivermectin metabolites that underwent deglycosylation or hydroxylation at spiroketal moiety were not active against An. stephensi at Cmax levels. Interestingly, half-lives of M1 (54.2 ± 4.7 h) and M4 (57.5 ± 13.2 h) were considerably longer than that of the parent compound ivermectin (38.9 ± 20.8 h). CONCLUSION In conclusion, the ivermectin metabolites M1 and M2 contribute to the activity of ivermectin against An. stephensi mosquitoes and could be responsible for the "post-ivermectin effect".
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Affiliation(s)
- Charlotte Kern
- Division of Clinical Pharmacology & Toxicology, Department of Internal Medicine, University Hospital Bern, Bern, Switzerland
- Graduate School for Health Sciences, University of Bern, Bern, Switzerland
| | - Pie Müller
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Carlos Chaccour
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Madrid, Spain
- Facultad de Medicina, Universidad de Navarra, Pamplona, Spain
| | - Matthias E Liechti
- Division of Clinical Pharmacology & Toxicology, Department of Biomedicine, University and University Hospital Basel, Basel, Switzerland
- Division of Clinical Pharmacology & Toxicology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Felix Hammann
- Division of Clinical Pharmacology & Toxicology, Department of Internal Medicine, University Hospital Bern, Bern, Switzerland
| | - Urs Duthaler
- Division of Clinical Pharmacology & Toxicology, Department of Biomedicine, University and University Hospital Basel, Basel, Switzerland.
- Division of Clinical Pharmacology & Toxicology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
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Kobylinski KC, Tipthara P, Wamaket N, Chainarin S, Kullasakboonsri R, Sriwichai P, Phasomkusolsil S, Hanboonkunupakarn B, Jittamala P, Gemmell R, Boyle J, Wrigley S, Steele J, White NJ, Tarning J. Ivermectin metabolites reduce Anopheles survival. Sci Rep 2023; 13:8131. [PMID: 37208382 DOI: 10.1038/s41598-023-34719-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 05/05/2023] [Indexed: 05/21/2023] Open
Abstract
Ivermectin mass drug administration to humans or livestock is a potential vector control tool for malaria elimination. The mosquito-lethal effect of ivermectin in clinical trials exceeds that predicted from in vitro laboratory experiments, suggesting that ivermectin metabolites have mosquito-lethal effect. The three primary ivermectin metabolites in humans (i.e., M1 (3″-O-demethyl ivermectin), M3 (4-hydroxymethyl ivermectin), and M6 (3″-O-demethyl, 4-hydroxymethyl ivermectin) were obtained by chemical synthesis or bacterial modification/metabolism. Ivermectin and its metabolites were mixed in human blood at various concentrations, blood-fed to Anopheles dirus and Anopheles minimus mosquitoes, and mortality was observed daily for fourteen days. Ivermectin and metabolite concentrations were quantified by liquid chromatography linked with tandem mass spectrometry to confirm the concentrations in the blood matrix. Results revealed that neither the LC50 nor LC90 values differed between ivermectin and its major metabolites for An. dirus or An. minimus., Additionally, there was no substantial differences in the time to median mosquito mortality when comparing ivermectin and its metabolites, demonstrating an equal rate of mosquito killing between the compounds evaluated. These results demonstrate that ivermectin metabolites have a mosquito-lethal effect equal to the parent compound, contributing to Anopheles mortality after treatment of humans.
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Affiliation(s)
- Kevin C Kobylinski
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand.
| | - Phornpimon Tipthara
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Narenrit Wamaket
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi Road, Bangkok, 10400, Thailand
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Sittinont Chainarin
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi Road, Bangkok, 10400, Thailand
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Rattawan Kullasakboonsri
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Patchara Sriwichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Siriporn Phasomkusolsil
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Borimas Hanboonkunupakarn
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Podjanee Jittamala
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Renia Gemmell
- Hypha Discovery Limited, 154B Brook Drive, Abingdon, OX14 4SD, Oxfordshire, UK
| | - John Boyle
- Hypha Discovery Limited, 154B Brook Drive, Abingdon, OX14 4SD, Oxfordshire, UK
| | - Stephen Wrigley
- Hypha Discovery Limited, 154B Brook Drive, Abingdon, OX14 4SD, Oxfordshire, UK
| | - Jonathan Steele
- Hypha Discovery Limited, 154B Brook Drive, Abingdon, OX14 4SD, Oxfordshire, UK
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Oxford, OX3 7BN, UK
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Ratchathewi, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Oxford, OX3 7BN, UK
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Chen I, Doum D, Mannion K, Hustedt J, Sovannaroth S, McIver D, Macdonald M, Lobo NF, Tatarsky A, Handley M, Neukom J. Applying the COM-B behavior model to inform the delivery of spatial repellents and insecticide-treated clothing among forest exposed populations in Mondulkiri Province, Cambodia. RESEARCH SQUARE 2023:rs.3.rs-2874672. [PMID: 37205382 PMCID: PMC10187415 DOI: 10.21203/rs.3.rs-2874672/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
BACKGROUND Southeast Asia is making tremendous progress towards their 2030 malaria elimination goal but needs new interventions to stop forest malaria. This study trials two new vector control tools, a volatile pyrethroid spatial repellent (VSPR) and insecticide-treated clothing (ITC), amongst forest-exposed populations in Mondulkiri Province Cambodia to inform their potential use for eliminating forest malaria. METHODS 21 forest-exposed individuals were given a questionnaire on their perceptions of malaria and preventive practices used, after which they trialed two products sequentially. Mixed methods were used to understand their experience, attitudes, and preferences regarding the products trialed. Quantitative data was summarized and qualitative insights were analyzed using thematic analysis, applying the Capability, Opportunity, Motivation Behavior Change (COM-B) model and Behavior Change Wheel Framework to identify intervention functions to support tailored product rollout amongst these populations. RESULTS Study participants reported a need for protection from mosquito bites in outdoor and forest-exposed settings and perceived both products trialed to be effective for this purpose. The VPSR product was preferred when travel was not required, whereas ITC was preferred for ease of use when going to the forest, especially in rainy conditions. COM-B analysis identified that key enablers for use of both products included their perceived efficacy and ease of use, which required no skill or preparation. For barriers to use, the odor of ITC was sometimes perceived as being toxic, as well as its inability to protect uncovered skin from mosquito bites, while the perceived usefulness of the VPSR product trialed was limited by its water sensitivity in rainy forest settings. Intervention components to encourage appropriate and sustained use of these products include education about how to use these products and what to expect, persuasion to use them from community leaders and targeted ads, and enablement to guarantee access. CONCLUSION The rollout of VPSRs and ITC amongst forest-exposed populations can be useful for eliminating malaria in Southeast Asia. Study findings can be applied to increase product uptake in Cambodia, while research efforts can aim to develop products that are rainproof, easy to use in forest settings, and have favorable odor profiles to target users.
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Affiliation(s)
| | | | | | - John Hustedt
- United States Agency for International Development
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10
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Schilling WHK, Jittamala P, Watson JA, Ekkapongpisit M, Siripoon T, Ngamprasertchai T, Luvira V, Pongwilai S, Cruz C, Callery JJ, Boyd S, Kruabkontho V, Ngernseng T, Tubprasert J, Abdad MY, Piaraksa N, Suwannasin K, Hanboonkunupakarn P, Hanboonkunupakarn B, Sookprome S, Poovorawan K, Thaipadungpanit J, Blacksell S, Imwong M, Tarning J, Taylor WRJ, Chotivanich V, Sangketchon C, Ruksakul W, Chotivanich K, Teixeira MM, Pukrittayakamee S, Dondorp AM, Day NPJ, Piyaphanee W, Phumratanaprapin W, White NJ. Pharmacometrics of high-dose ivermectin in early COVID-19 from an open label, randomized, controlled adaptive platform trial (PLATCOV). eLife 2023; 12:e83201. [PMID: 36803992 PMCID: PMC9988254 DOI: 10.7554/elife.83201] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 02/03/2023] [Indexed: 02/22/2023] Open
Abstract
Background There is no generally accepted methodology for in vivo assessment of antiviral activity in SARS-CoV-2 infections. Ivermectin has been recommended widely as a treatment of COVID-19, but whether it has clinically significant antiviral activity in vivo is uncertain. Methods In a multicentre open label, randomized, controlled adaptive platform trial, adult patients with early symptomatic COVID-19 were randomized to one of six treatment arms including high-dose oral ivermectin (600 µg/kg daily for 7 days), the monoclonal antibodies casirivimab and imdevimab (600 mg/600 mg), and no study drug. The primary outcome was the comparison of viral clearance rates in the modified intention-to-treat population. This was derived from daily log10 viral densities in standardized duplicate oropharyngeal swab eluates. This ongoing trial is registered at https://clinicaltrials.gov/ (NCT05041907). Results Randomization to the ivermectin arm was stopped after enrolling 205 patients into all arms, as the prespecified futility threshold was reached. Following ivermectin, the mean estimated rate of SARS-CoV-2 viral clearance was 9.1% slower (95% confidence interval [CI] -27.2% to +11.8%; n=45) than in the no drug arm (n=41), whereas in a preliminary analysis of the casirivimab/imdevimab arm it was 52.3% faster (95% CI +7.0% to +115.1%; n=10 (Delta variant) vs. n=41). Conclusions High-dose ivermectin did not have measurable antiviral activity in early symptomatic COVID-19. Pharmacometric evaluation of viral clearance rate from frequent serial oropharyngeal qPCR viral density estimates is a highly efficient and well-tolerated method of assessing SARS-CoV-2 antiviral therapeutics in vitro. Funding 'Finding treatments for COVID-19: A phase 2 multi-centre adaptive platform trial to assess antiviral pharmacodynamics in early symptomatic COVID-19 (PLAT-COV)' is supported by the Wellcome Trust Grant ref: 223195/Z/21/Z through the COVID-19 Therapeutics Accelerator. Clinical trial number NCT05041907.
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Affiliation(s)
- William HK Schilling
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Podjanee Jittamala
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - James A Watson
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Maneerat Ekkapongpisit
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Tanaya Siripoon
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Thundon Ngamprasertchai
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Viravarn Luvira
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Sasithorn Pongwilai
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Cintia Cruz
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - James J Callery
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Simon Boyd
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Varaporn Kruabkontho
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Thatsanun Ngernseng
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Jaruwan Tubprasert
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Mohammad Yazid Abdad
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Nattaporn Piaraksa
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Kanokon Suwannasin
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | | | - Borimas Hanboonkunupakarn
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | | | - Kittiyod Poovorawan
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Janjira Thaipadungpanit
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Stuart Blacksell
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Mallika Imwong
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Walter RJ Taylor
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | | | - Chunlanee Sangketchon
- Faculty of Science and Health Technology, Navamindradhiraj UniversityBangkokThailand
| | - Wiroj Ruksakul
- Faculty of Medicine, Navamindradhiraj UniversityBangkokThailand
| | - Kesinee Chotivanich
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Mauro Martins Teixeira
- Department of Biochemistry and Immunology, Universidade Federal de Minas GeraisBelo HorizonteBrazil
| | - Sasithon Pukrittayakamee
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Nicholas PJ Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Watcharapong Piyaphanee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Weerapong Phumratanaprapin
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
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11
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Soumare HM, Dabira ED, Camara MM, Jadama L, Gaye PM, Kanteh S, Jawara EA, Njie AK, Sanneh F, Ndiath MO, Lindsay SW, Conteh B, Ceesay S, Mohammed N, Ooko M, Bradley J, Drakeley C, Erhart A, Bousema T, D'Alessandro U. Entomological impact of mass administration of ivermectin and dihydroartemisinin-piperaquine in The Gambia: a cluster-randomized controlled trial. Parasit Vectors 2022; 15:435. [PMID: 36397132 PMCID: PMC9673448 DOI: 10.1186/s13071-022-05557-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/16/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Vector control interventions in sub-Saharan Africa rely on insecticide-treated nets and indoor residual spraying. Insecticide resistance, poor coverage of interventions, poor quality nets and changes in vector behavior threaten the effectiveness of these interventions and, consequently, alternative tools are needed. Mosquitoes die after feeding on humans or animals treated with ivermectin (IVM). Mass drug administration (MDA) with IVM could reduce vector survival and decrease malaria transmission. The entomological impact of MDA of combined IVM and dihydroartemisinin-piperaquine was assessed in a community-based, cluster-randomized trial. METHODS A cluster-randomized trial was implemented in 2018 and 2019 in 32 villages in the Upper River Region, The Gambia. The with the inhabitants of 16 intervention villages eligible to receive three monthly rounds of MDA at the beginning of the malaria transmission season. Entomological surveillance with light traps and human landing catches (HLC) was carried out during a 7- to 14-day period after each round of MDA, and then monthly until the end of the year. The mosquitocidal effect of IVM was determined by direct membrane feeding assays. RESULTS Of the 15,017 mosquitoes collected during the study period, 99.65% (n = 14,965) were Anopheles gambiae sensu lato (An. gambiae s.l.), comprising Anopheles arabiensis (56.2%), Anopheles coluzzii (24.5%), Anopheles gambiae sensu stricto (An. gembiae s.s.; 16.0%) and Anopheles funestus sensu lato (An. funestus s.l.; 0.35%). No effect of the intervention on vector parity was observed. Vector density determined on light trap collections was significantly lower in the intervention villages in 2019 (adjusted incidence rate ratio: 0.39; 95% confidence interval [CI]: 0.20, 0.74; P = 0.005) but not in 2018. However, vector density determined in HLC collections was similar in both the intervention and control villages. The entomological inoculation rate was significantly lower in the intervention villages than in the control villages (odds ratio: 0.36, 95% CI: 0.19, 0.70; P = 0·003). Mosquito mortality was significantly higher when blood fed on IVM-treated individuals up to 21 days post-treatment, particularly in adults and individuals with a higher body mass index. CONCLUSION Mass drug administration with IVM decreased vector density and the entomological inoculation rate while the effect on vector parity was less clear. Survival of mosquitoes fed on blood collected from IVM-treated individuals was significantly lower than that in mosquitoes which fed on controls. The influence of host characteristics on mosquito survivorship indicated that dose optimization could improve IVM efficacy. Future detailed entomological evaluation trials in which IVM is administered as stand-alone intervention may elucidate the contribution of this drug to the observed reduction in transmission.
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Affiliation(s)
- Harouna M Soumare
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia.
| | - Edgard Diniba Dabira
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Muhammed M Camara
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Lamin Jadama
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Pa Modou Gaye
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Sainey Kanteh
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Ebrima A Jawara
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Amie Kolleh Njie
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Fatou Sanneh
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Mamadou Ousman Ndiath
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | | | - Bakary Conteh
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Sainey Ceesay
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Nuredin Mohammed
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Michael Ooko
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - John Bradley
- MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Chris Drakeley
- Faculty of Infectious & Tropical Diseases, The London School of Hygiene and Tropical Medicine, London, UK
| | - Annette Erhart
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
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12
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Shah JA. Learnings from Thailand in building strong surveillance for malaria elimination. Nat Commun 2022; 13:2677. [PMID: 35562343 PMCID: PMC9106678 DOI: 10.1038/s41467-022-30267-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/20/2022] [Indexed: 12/02/2022] Open
Affiliation(s)
- Jui A Shah
- RTI International, Unit 406, 208 Wireless Road, Lumpini, Pathumwan, Bangkok, 10330, Thailand.
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13
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Maldonado JH, Grundmann O. Drug-drug Interactions of Artemisinin-based Combination Therapies in Malaria Treatment: A narrative review of the literature. J Clin Pharmacol 2022; 62:1197-1205. [PMID: 35543380 DOI: 10.1002/jcph.2073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/05/2022] [Indexed: 11/11/2022]
Abstract
Artemisinin is an antimalarial compound derived from the plant Artemisia annua L., also known as sweet wormwood. According to the World Health Organization, artemisinin-based combination therapy (ACT) is an essential treatment for malaria, specifically Plasmodium falciparum, which accounts for most of malaria related mortality. ACT used to treat uncomplicated malaria include artemether-lumefantrine, artesunate-amodiaquine, artesunate-mefloquine, artesunate-sulphadoxine-pyrimethamine, and dihydroartemisinin-piperaquine. Although the mechanism of action and clinical capabilities of artemisinin in malaria treatment are widely known, more information on the potential for drug interactions needs to be further investigated. Some studies show pharmacokinetic and pharmacodynamic drug interactions with HIV-antiviral treatment but few studies have been conducted on most other drug classes. Based on known genotypes of cytochrome P450 (CYP) enzymes, CYP2B6 and CYP3A are primarily involved in the metabolism of artemisinin and its derivatives. Reduced functions in these enzymes can lead to subtherapeutic concentrations of the active metabolite dihydroartemisinin that may cause treatment failure which has been shown in some studies with cardiovascular, antibiotic, and antiparasitic drugs. Although the clinical importance remains unclear to date, clinicians should be aware of potential drug-drug interactions and monitor patients on ACT closely. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Joyce Hernandez Maldonado
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, United States of America
| | - Oliver Grundmann
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, United States of America
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Vythilingam I, Chua TH, Liew JWK, Manin BO, Ferguson HM. The vectors of Plasmodium knowlesi and other simian malarias Southeast Asia: challenges in malaria elimination. ADVANCES IN PARASITOLOGY 2021; 113:131-189. [PMID: 34620382 DOI: 10.1016/bs.apar.2021.08.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Plasmodium knowlesi, a simian malaria parasite of great public health concern has been reported from most countries in Southeast Asia and exported to various countries around the world. Currently P. knowlesi is the predominant species infecting humans in Malaysia. Besides this species, other simian malaria parasites such as P. cynomolgi and P. inui are also infecting humans in the region. The vectors of P. knowlesi and other Asian simian malarias belong to the Leucosphyrus Group of Anopheles mosquitoes which are generally forest dwelling species. Continual deforestation has resulted in these species moving into forest fringes, farms, plantations and human settlements along with their macaque hosts. Limited studies have shown that mosquito vectors are attracted to both humans and macaque hosts, preferring to bite outdoors and in the early part of the night. We here review the current status of simian malaria vectors and their parasites, knowledge of vector competence from experimental infections and discuss possible vector control measures. The challenges encountered in simian malaria elimination are also discussed. We highlight key knowledge gaps on vector distribution and ecology that may impede effective control strategies.
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Affiliation(s)
- Indra Vythilingam
- Department of Parasitology, University of Malaya, Kuala Lumpur, Malaysia.
| | - Tock Hing Chua
- Department of Pathobiology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Sabah Malaysia, Kota Kinabalu, Sabah, Malaysia.
| | - Jonathan Wee Kent Liew
- Department of Parasitology, University of Malaya, Kuala Lumpur, Malaysia; Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Benny O Manin
- Department of Pathobiology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Sabah Malaysia, Kota Kinabalu, Sabah, Malaysia
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, United Kingdom
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15
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Wamaket N, Khamprapa O, Chainarin S, Thamsawet P, Ninsaeng U, Thongsalee S, Suwan V, Sakolvaree J, Takhampunya R, Davidson SA, McCardle PW, Sa-Angchai P, Mukaka M, Kiattibutr K, Khamsiriwatchara A, Nguitragool W, Sattabongkot J, Sirichaisinthop J, Kobylinski KC. Anopheles bionomics in a malaria endemic area of southern Thailand. Parasit Vectors 2021; 14:378. [PMID: 34315509 PMCID: PMC8317318 DOI: 10.1186/s13071-021-04870-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/02/2021] [Indexed: 12/26/2022] Open
Abstract
Background Ivermectin mass drug administration (MDA) could accelerate malaria elimination in the Greater Mekong Subregion. This study was performed to characterize the bionomics of Anopheles in Surat Thani province, Thailand. Methods Mosquitoes were collected via human landing collections between February and October 2019. Anopheles mosquitoes were morphologically identified to species. Primary Anopheles malaria vectors were dissected to assess parity status, and a subset were evaluated for molecular identification and Plasmodium detection. Results A total of 17,348 mosquitoes were collected during the study period; of these, 5777 were Anopheles mosquitoes. Morphological studies identified 15 Anopheles species, of which the most abundant were Anopheles minimus (s.l.) (87.16%, n = 5035), An. dirus s.l. (7.05%, n = 407) and An. barbirostris s.l. (2.86%, n = 165). Molecular identification confirmed that of the An. minimus s.l. mosquitoes collected, 99.80% were An. minimus (s.s.) (n = 484) and 0.2% were An. aconitus (n = 1), of the An. dirus (s.l.) collected, 100% were An. baimaii (n = 348), and of the An. maculatus (s.l.) collected, 93.62% were An. maculatus (s.s.) (n = 44) and 6.38% were An. sawadwongporni (n = 3). No Anopheles mosquito tested was Plasmodium positive (0/879). An average of 11.46 Anopheles were captured per collector per night. There were differences between species in hour of collection (Kruskal–Wallis H-test: χ2 = 80.89, P < 0.0001, n = 5666), with more An. barbirostris (s.l.) and An. maculatus (s.l.) caught earlier compared to An. minimus (s.l.) (P = 0.0001 and P < 0.0001, respectively) and An. dirus (s.l.) (P = 0.0082 and P < 0.001, respectively). The proportion of parous An. minimus (s.l.) captured by hour increased throughout the night (Wald Chi-square: χ2 = 17.31, P = 0.000, odds ratio = 1.0535, 95% confidence interval 1.0279–1.0796, n = 3400). Overall, An. minimus (s.l.) parity was 67.68% (2375/3509) with an intra-cluster correlation of 0.0378. A power calculation determined that an An. minimus (s.l.) parity reduction treatment effect size = 34%, with four clusters per treatment arm and a minimum of 300 mosquitoes dissected per cluster, at an α = 0.05, will provide 82% power to detect a significant difference following ivermectin MDA. Conclusions The study area in Surat Thani province is an ideal location to evaluate the impact of ivermectin MDA on An. minimus parity. Graphical abstract ![]()
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Affiliation(s)
- Narenrit Wamaket
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand.,Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Oranicha Khamprapa
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand.,Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Sittinont Chainarin
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand.,Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Panisa Thamsawet
- Surat Thani Vector-Borne Diseases Control Center 11.3, Muang, Surat Thani, Thailand
| | - Ubolrat Ninsaeng
- Surat Thani Vector-Borne Diseases Control Center 11.3, Muang, Surat Thani, Thailand
| | - Suttipong Thongsalee
- Surat Thani Vector-Borne Diseases Control Center 11.3, Muang, Surat Thani, Thailand
| | - Veerast Suwan
- Surat Thani Vector-Borne Diseases Control Center 11.3, Muang, Surat Thani, Thailand
| | - Jira Sakolvaree
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand
| | - Ratree Takhampunya
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand
| | - Silas A Davidson
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand
| | - Patrick W McCardle
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand
| | - Patiwat Sa-Angchai
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Mavuto Mukaka
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Kirakorn Kiattibutr
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Amnat Khamsiriwatchara
- Center of Excellence for Biomedical and Public Health Informatics, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Wang Nguitragool
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand.,Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
| | | | - Kevin C Kobylinski
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok, Thailand.
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16
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Coonahan ES, Yang KA, Pecic S, De Vos M, Wellems TE, Fay MP, Andersen JF, Tarning J, Long CA. Structure-switching aptamer sensors for the specific detection of piperaquine and mefloquine. Sci Transl Med 2021; 13:13/585/eabe1535. [PMID: 33731432 DOI: 10.1126/scitranslmed.abe1535] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 02/22/2021] [Indexed: 12/28/2022]
Abstract
Tracking antimalarial drug use and efficacy is essential for monitoring the current spread of antimalarial drug resistance. However, available methods for determining tablet quality and patient drug use are often inaccessible, requiring well-equipped laboratories capable of performing liquid chromatography-mass spectrometry (LC-MS). Here, we report the development of aptamer-based fluorescent sensors for the rapid, specific detection of the antimalarial compounds piperaquine and mefloquine-two slow-clearing partner drugs in current first-line artemisinin-based combination therapies (ACTs). Highly selective DNA aptamers were identified that bind piperaquine and mefloquine with dissociation constants (K d's) measured in the low nanomolar range via two independent methods. The aptamers were isolated from a library of single-stranded DNA molecules using a capture-systematic evolution of ligands by exponential enrichment (SELEX) technique and then adapted into structure-switching aptamer fluorescent sensors. Sensor performance was optimized for the detection of drug from human serum and crushed tablets, resulting in two sensing platforms. The patient sample platform was validated against an LC-MS standard drug detection method in samples from healthy volunteers and patients with malaria. This assay provides a rapid and inexpensive method for tracking antimalarial drug use and quality for the containment and study of parasite resistance, a major priority for malaria elimination campaigns. This sensor platform allows for flexibility of sample matrix and can be easily adapted to detect other small-molecule drugs.
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Affiliation(s)
- Erin S Coonahan
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA.,Institute of Biomedical Engineering, University of Oxford, Oxford OX3 7DQ, UK.,Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Kyung-Ae Yang
- Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Stevan Pecic
- Department of Chemistry and Biochemistry, California State University , Fullerton, CA 92831, USA
| | - Maarten De Vos
- Institute of Biomedical Engineering, University of Oxford, Oxford OX3 7DQ, UK.,Department of Electrical Engineering (ESAT), KU Leuven, Leuven 3000, Belgium.,Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Thomas E Wellems
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA
| | - Michael P Fay
- Biostatistics Research Branch, DCR, NIAID, NIH, Rockville, MD 20852, USA
| | - John F Andersen
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7LG, UK
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA.
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17
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Singh L, Singh K. Ivermectin: A Promising Therapeutic for Fighting Malaria. Current Status and Perspective. J Med Chem 2021; 64:9711-9731. [PMID: 34242031 DOI: 10.1021/acs.jmedchem.1c00498] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Finding new chemotherapeutic interventions to treat malaria through repurposing of time-tested drugs and rigorous design of new drugs using tools of rational drug design remains one of the most sought strategies at the disposal of medicinal chemists. Ivermectin, a semisynthetic derivative of avermectin B1, is among the efficacious drugs used in mass drug administration drives employed against onchocerciasis, lymphatic filariasis, and several other parasitic diseases in humans. In this review, we present the prowess of ivermectin, a potent endectocide, in the control of malaria through vector control to reduce parasite transmission combined with efficacious chemoprevention to reduce malaria-related fatalities.
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Affiliation(s)
- Lovepreet Singh
- Department of Chemistry, UGC Centre for Advanced Studies-II, Guru Nanak Dev University, Amritsar-143 005, India
| | - Kamaljit Singh
- Department of Chemistry, UGC Centre for Advanced Studies-II, Guru Nanak Dev University, Amritsar-143 005, India
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18
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Nicolas P, Kiuru C, Wagah MG, Muturi M, Duthaler U, Hammann F, Maia M, Chaccour C. Potential metabolic resistance mechanisms to ivermectin in Anopheles gambiae: a synergist bioassay study. Parasit Vectors 2021; 14:172. [PMID: 33743783 PMCID: PMC7981804 DOI: 10.1186/s13071-021-04675-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/07/2021] [Indexed: 11/10/2022] Open
Abstract
Background Despite remarkable success obtained with current malaria vector control strategies in the last 15 years, additional innovative measures will be needed to achieve the ambitious goals for malaria control set for 2030 by the World Health Organization (WHO). New tools will need to address insecticide resistance and residual transmission as key challenges. Endectocides such as ivermectin are drugs that kill mosquitoes which feed on treated subjects. Mass administration of ivermectin can effectively target outdoor and early biting vectors, complementing the still effective conventional tools. Although this approach has garnered attention, development of ivermectin resistance is a potential pitfall. Herein, we evaluate the potential role of xenobiotic pumps and cytochrome P450 enzymes in protecting mosquitoes against ivermectin by active efflux and metabolic detoxification, respectively. Methods We determined the lethal concentration 50 for ivermectin in colonized Anopheles gambiae; then we used chemical inhibitors and inducers of xenobiotic pumps and cytochrome P450 enzymes in combination with ivermectin to probe the mechanism of ivermectin detoxification. Results Dual inhibition of xenobiotic pumps and cytochromes was found to have a synergistic effect with ivermectin, greatly increasing mosquito mortality. Inhibition of xenobiotic pumps alone had no effect on ivermectin-induced mortality. Induction of xenobiotic pumps and cytochromes may confer partial protection from ivermectin. Conclusion There is a clear pathway for development of ivermectin resistance in malaria vectors. Detoxification mechanisms mediated by cytochrome P450 enzymes are more important than xenobiotic pumps in protecting mosquitoes against ivermectin.![]()
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Affiliation(s)
- Patricia Nicolas
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, 1929, Maputo, Mozambique
| | - Caroline Kiuru
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, 1929, Maputo, Mozambique
| | - Martin G Wagah
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 91SA, UK.,Department of Biosciences, KEMRI Wellcome Trust Research Programme, Kilifi, 230-80108, Kenya
| | - Martha Muturi
- Department of Biosciences, KEMRI Wellcome Trust Research Programme, Kilifi, 230-80108, Kenya
| | - Urs Duthaler
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University and University Hospital Basel, 4056, Basel, Switzerland.,Division of Clinical Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056, Basel, Switzerland
| | - Felix Hammann
- Division of Clinical Pharmacology and Toxicology, Department of Internal Medicine, University Hospital Bern, 3010, Bern, Switzerland
| | - Marta Maia
- Department of Biosciences, KEMRI Wellcome Trust Research Programme, Kilifi, 230-80108, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Carlos Chaccour
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain. .,Ifakara Health Institute, Ifakara, 67501, United Republic of Tanzania. .,Facultad de Medicina, Universidad de Navarra, 31008, Pamplona, Spain.
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19
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A systematic review and an individual patient data meta-analysis of ivermectin use in children weighing less than fifteen kilograms: Is it time to reconsider the current contraindication? PLoS Negl Trop Dis 2021; 15:e0009144. [PMID: 33730099 PMCID: PMC7968658 DOI: 10.1371/journal.pntd.0009144] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/13/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Oral ivermectin is a safe broad spectrum anthelminthic used for treating several neglected tropical diseases (NTDs). Currently, ivermectin use is contraindicated in children weighing less than 15 kg, restricting access to this drug for the treatment of NTDs. Here we provide an updated systematic review of the literature and we conducted an individual-level patient data (IPD) meta-analysis describing the safety of ivermectin in children weighing less than 15 kg. METHODOLOGY/PRINCIPAL FINDINGS A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for IPD guidelines by searching MEDLINE via PubMed, Web of Science, Ovid Embase, LILACS, Cochrane Database of Systematic Reviews, TOXLINE for all clinical trials, case series, case reports, and database entries for reports on the use of ivermectin in children weighing less than 15 kg that were published between 1 January 1980 to 25 October 2019. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42017056515. A total of 3,730 publications were identified, 97 were selected for potential inclusion, but only 17 sources describing 15 studies met the minimum criteria which consisted of known weights of children less than 15 kg linked to possible adverse events, and provided comprehensive IPD. A total of 1,088 children weighing less than 15 kg were administered oral ivermectin for one of the following indications: scabies, mass drug administration for scabies control, crusted scabies, cutaneous larva migrans, myiasis, pthiriasis, strongyloidiasis, trichuriasis, and parasitic disease of unknown origin. Overall a total of 1.4% (15/1,088) of children experienced 18 adverse events all of which were mild and self-limiting. No serious adverse events were reported. CONCLUSIONS/SIGNIFICANCE Existing limited data suggest that oral ivermectin in children weighing less than 15 kilograms is safe. Data from well-designed clinical trials are needed to provide further assurance.
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20
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Tipthara P, Kobylinski KC, Godejohann M, Hanboonkunupakarn B, Roth A, Adams JH, White NJ, Jittamala P, Day NPJ, Tarning J. Identification of the metabolites of ivermectin in humans. Pharmacol Res Perspect 2021; 9:e00712. [PMID: 33497030 PMCID: PMC7836931 DOI: 10.1002/prp2.712] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/11/2022] Open
Abstract
Mass drug administration of ivermectin has been proposed as a possible malaria elimination tool. Ivermectin exhibits a mosquito-lethal effect well beyond its biological half-life, suggesting the presence of active slowly eliminated metabolites. Human liver microsomes, primary human hepatocytes, and whole blood from healthy volunteers given oral ivermectin were used to identify ivermectin metabolites by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry. The molecular structures of metabolites were determined by mass spectrometry and verified by nuclear magnetic resonance. Pure cytochrome P450 enzyme isoforms were used to elucidate the metabolic pathways. Thirteen different metabolites (M1-M13) were identified after incubation of ivermectin with human liver microsomes. Three (M1, M3, and M6) were the major metabolites found in microsomes, hepatocytes, and blood from volunteers after oral ivermectin administration. The chemical structure, defined by LC-MS/MS and NMR, indicated that M1 is 3″-O-demethyl ivermectin, M3 is 4-hydroxymethyl ivermectin, and M6 is 3″-O-demethyl, 4-hydroxymethyl ivermectin. Metabolic pathway evaluations with characterized cytochrome P450 enzymes showed that M1, M3, and M6 were produced primarily by CYP3A4, and that M1 was also produced to a small extent by CYP3A5. Demethylated (M1) and hydroxylated (M3) ivermectin were the main human in vivo metabolites. Further studies are needed to characterize the pharmacokinetic properties and mosquito-lethal activity of these metabolites.
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Affiliation(s)
- Phornpimon Tipthara
- Mahidol Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
| | - Kevin C. Kobylinski
- Department of EntomologyArmed Forces Research Institute of Medical SciencesBangkokThailand
| | | | - Borimas Hanboonkunupakarn
- Mahidol Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
- Department of Clinical Tropical MedicineFaculty of Tropical MedicineMahidol UniversityBangkokThailand
| | - Alison Roth
- Center for Global Health and Infectious Diseases ResearchCollege of Public HealthUniversity of South FloridaTampaFLUSA
- Department of Drug DiscoveryExperimental Therapeutics BranchWalter Reed Army Institute of ResearchSilver SpringMDUSA
| | - John H. Adams
- Center for Global Health and Infectious Diseases ResearchCollege of Public HealthUniversity of South FloridaTampaFLUSA
| | - Nicholas J. White
- Mahidol Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global HealthNuffield Department of Clinical MedicineUniversity of OxfordOxfordUnited Kingdom
| | - Podjanee Jittamala
- Mahidol Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
- Department of Tropical HygieneFaculty of Tropical MedicineMahidol UniversityBangkokThailand
| | - Nicholas P. J. Day
- Mahidol Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global HealthNuffield Department of Clinical MedicineUniversity of OxfordOxfordUnited Kingdom
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global HealthNuffield Department of Clinical MedicineUniversity of OxfordOxfordUnited Kingdom
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21
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Dabira ED, Soumare HM, Lindsay SW, Conteh B, Ceesay F, Bradley J, Kositz C, Broekhuizen H, Kandeh B, Fehr AE, Nieto-Sanchez C, Ribera JM, Peeters Grietens K, Smit MR, Drakeley C, Bousema T, Achan J, D'Alessandro U. Mass Drug Administration With High-Dose Ivermectin and Dihydroartemisinin-Piperaquine for Malaria Elimination in an Area of Low Transmission With High Coverage of Malaria Control Interventions: Protocol for the MASSIV Cluster Randomized Clinical Trial. JMIR Res Protoc 2020; 9:e20904. [PMID: 33211022 PMCID: PMC7714640 DOI: 10.2196/20904] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/28/2020] [Accepted: 08/03/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND With a decline in malaria burden, innovative interventions and tools are required to reduce malaria transmission further. Mass drug administration (MDA) of artemisinin-based combination therapy (ACT) has been identified as a potential tool to further reduce malaria transmission, where coverage of vector control interventions is already high. However, the impact is limited in time. Combining an ACT with an endectocide treatment that is able to reduce vector survival, such as ivermectin (IVM), could increase the impact of MDA and offer a new tool to reduce malaria transmission. OBJECTIVE The study objective is to evaluate the impact of MDA with IVM plus dihydroartemisinin-piperaquine (DP) on malaria transmission in an area with high coverage of malaria control interventions. METHODS The study is a cluster randomized trial in the Upper River Region of The Gambia and included 32 villages (16 control and 16 intervention). A buffer zone of ~2 km was created around all intervention clusters. MDA with IVM plus DP was implemented in all intervention villages and the buffer zones; control villages received standard malaria interventions according to the Gambian National Malaria Control Program plans. RESULTS The MDA campaigns were carried out from August to October 2018 for the first year and from July to September 2019 for the second year. Statistical analysis will commence once the database is completed, cleaned, and locked. CONCLUSIONS This is the first cluster randomized clinical trial of MDA with IVM plus DP. The results will provide evidence on the impact of MDA with IVM plus DP on malaria transmission. TRIAL REGISTRATION ClinicalTrials.gov NCT03576313; https://clinicaltrials.gov/ct2/show/NCT03576313. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/20904.
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Affiliation(s)
- Edgard Diniba Dabira
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Harouna M Soumare
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Steven W Lindsay
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Bakary Conteh
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Fatima Ceesay
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - John Bradley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Christian Kositz
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Balla Kandeh
- National Malaria Control Program, The Gambia, Banjul, Gambia
| | - Alexandra E Fehr
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- Vrije Universiteit Amsterdam, Athena Institute, Amsterdam, Netherlands
| | - Claudia Nieto-Sanchez
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Joan Muela Ribera
- Medial Anthropology Research Center, Universitat Rovira i Virgili, Tarragona, Spain
| | - Koen Peeters Grietens
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Menno Roderick Smit
- Amsterdam Centre for Global Child Health, Emma Children's Hospital, Amsterdam University Medical Centres, Amsterdam, The Netherlands, Amsterdam, Netherlands
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Radboud University Medical Centre, Nijmegen, Netherlands
| | - Jane Achan
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Umberto D'Alessandro
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
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22
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Safety, Pharmacokinetics, and Activity of High-Dose Ivermectin and Chloroquine against the Liver Stage of Plasmodium cynomolgi Infection in Rhesus Macaques. Antimicrob Agents Chemother 2020; 64:AAC.00741-20. [PMID: 32660993 PMCID: PMC7449176 DOI: 10.1128/aac.00741-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 06/30/2020] [Indexed: 12/11/2022] Open
Abstract
Previously, ivermectin (1 to 10 mg/kg of body weight) was shown to inhibit the liver-stage development of Plasmodium berghei in orally dosed mice. Here, ivermectin showed inhibition of the in vitro development of Plasmodium cynomolgi schizonts (50% inhibitory concentration [IC50], 10.42 μM) and hypnozoites (IC50, 29.24 μM) in primary macaque hepatocytes when administered as a high dose prophylactically but not when administered in radical cure mode. Previously, ivermectin (1 to 10 mg/kg of body weight) was shown to inhibit the liver-stage development of Plasmodium berghei in orally dosed mice. Here, ivermectin showed inhibition of the in vitro development of Plasmodium cynomolgi schizonts (50% inhibitory concentration [IC50], 10.42 μM) and hypnozoites (IC50, 29.24 μM) in primary macaque hepatocytes when administered as a high dose prophylactically but not when administered in radical cure mode. The safety, pharmacokinetics, and efficacy of oral ivermectin (0.3, 0.6, and 1.2 mg/kg) with and without chloroquine (10 mg/kg) administered for 7 consecutive days were evaluated for prophylaxis or radical cure of P. cynomolgi liver stages in rhesus macaques. No inhibition or delay to blood-stage P. cynomolgi parasitemia was observed at any ivermectin dose (0.3, 0.6, and 1.2 mg/kg). Ivermectin (0.6 and 1.2 mg/kg) and chloroquine (10 mg/kg) in combination were well-tolerated with no adverse events and no significant pharmacokinetic drug-drug interactions observed. Repeated daily ivermectin administration for 7 days did not inhibit ivermectin bioavailability. It was recently demonstrated that both ivermectin and chloroquine inhibit replication of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. Further ivermectin and chloroquine trials in humans are warranted to evaluate their role in Plasmodium vivax control and as adjunctive therapies against COVID-19 infections.
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23
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El-Saber Batiha G, Alqahtani A, Ilesanmi OB, Saati AA, El-Mleeh A, Hetta HF, Magdy Beshbishy A. Avermectin Derivatives, Pharmacokinetics, Therapeutic and Toxic Dosages, Mechanism of Action, and Their Biological Effects. Pharmaceuticals (Basel) 2020; 13:ph13080196. [PMID: 32824399 PMCID: PMC7464486 DOI: 10.3390/ph13080196] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/09/2020] [Accepted: 08/13/2020] [Indexed: 12/15/2022] Open
Abstract
Avermectins are a group of drugs that occurs naturally as a product of fermenting Streptomyces avermitilis, an actinomycetes, isolated from the soil. Eight different structures, including ivermectin, abamectin, doramectin, eprinomectin, moxidectin, and selamectin, were isolated and divided into four major components (A1a, A2a, B1a and B2a) and four minor components (A1b, A2b, B1b, and B2b). Avermectins are generally used as a pesticide for the treatment of pests and parasitic worms as a result of their anthelmintic and insecticidal properties. Additionally, they possess anticancer, anti-diabetic, antiviral, antifungal, and are used for treatment of several metabolic disorders. Avermectin generally works by preventing the transmission of electrical impulse in the muscle and nerves of invertebrates, by amplifying the glutamate effects on the invertebrates-specific gated chloride channel. Avermectin has unwanted effects or reactions, especially when administered indiscriminately, which include respiratory failure, hypotension, and coma. The current review examines the mechanism of actions, biosynthesis, safety, pharmacokinetics, biological toxicity and activities of avermectins.
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Affiliation(s)
- Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, Egypt
- Correspondence: or (G.E.-S.B.); (A.M.B.)
| | - Ali Alqahtani
- Department of Pharmacology, College of Pharmacy, King Khalid University, Guraiger, Abha 62529, Saudi Arabia;
| | - Omotayo B. Ilesanmi
- Department of Biochemistry, Faculty of Science, Federal University Otuoke, Otuoke 561, Nigeria;
| | - Abdullah A. Saati
- Department of Community Medicine & Pilgrims Healthcare, Faculty of Medicine, Umm Al-Qura University Makkah, Mecca 24382, Saudi Arabia;
| | - Amany El-Mleeh
- Department of Pharmacology, Faculty of Veterinary Medicine, Menoufia University, Shibin Al Kawm 32511, Egypt;
| | - Helal F. Hetta
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut 71515, Egypt;
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45221, USA
| | - Amany Magdy Beshbishy
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-13, Inada-cho, Obihiro 080-8555, Hokkaido, Japan
- Correspondence: or (G.E.-S.B.); (A.M.B.)
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24
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Christofferson RC, Parker DM, Overgaard HJ, Hii J, Devine G, Wilcox BA, Nam VS, Abubakar S, Boyer S, Boonnak K, Whitehead SS, Huy R, Rithea L, Sochantha T, Wellems TE, Valenzuela JG, Manning JE. Current vector research challenges in the greater Mekong subregion for dengue, Malaria, and Other Vector-Borne Diseases: A report from a multisectoral workshop March 2019. PLoS Negl Trop Dis 2020; 14:e0008302. [PMID: 32730249 PMCID: PMC7392215 DOI: 10.1371/journal.pntd.0008302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Rebecca C. Christofferson
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Daniel M. Parker
- University of California, Irvine, California, United States of America
| | | | | | - Gregor Devine
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Bruce A. Wilcox
- ASEAN Institute for Health Development, Mahidol University, Nakhon Pathom, Thailand
| | - Vu Sinh Nam
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Sazaly Abubakar
- Tropical Infectious Diseases Research and Education Center, Kuala Lumpur, Malaysia
| | | | - Kobporn Boonnak
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Stephen S. Whitehead
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Rekol Huy
- National Center for Parasitology Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Leang Rithea
- National Center for Parasitology Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Tho Sochantha
- National Center for Parasitology Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Thomas E. Wellems
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Jesus G. Valenzuela
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Jessica E. Manning
- US National Institute of Allergy and Infectious Diseases, Phnom Penh, Cambodia
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