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Santos A, Brito M, Silva E, Rocha F, Oliveira A, Dávila R, Gama H, Albuquerque J, Paiva M, Baía-Silva D, Sampaio V, Balieiro P, Rufatto R, Grewal Daumerie P, Peterka C, Edilson Lima F, Monteiro W, Arcanjo A, Silva R, Batista Pereira D, Lacerda M, Murta F. Perspectives of healthcare professionals on training for quantitative G6PD testing during implementation of tafenoquine in Brazil (QualiTRuST Study). PLoS Negl Trop Dis 2024; 18:e0012197. [PMID: 38837977 PMCID: PMC11152287 DOI: 10.1371/journal.pntd.0012197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 05/06/2024] [Indexed: 06/07/2024] Open
Abstract
Effective radical cure of Plasmodium vivax malaria is essential for malaria elimination in Brazil. P. vivax radical cure requires administration of a schizonticide, such as chloroquine, plus an 8-aminoquinoline. However, 8-aminoquinolines cause hemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, requiring prior screening to exclude those at risk. Brazil is pioneering the implementation of tafenoquine, a single-dose 8-aminoquinoline indicated for P. vivax patients with >70% of normal G6PD activity. Tafenoquine implementation in Manaus and Porto Velho, two municipalities located in the western Brazilian Amazon, included comprehensive training of healthcare professionals (HCPs) on point-of-care quantitative G6PD testing and a new treatment algorithm for P. vivax radical cure incorporating tafenoquine. Training was initially provided to higher-level facilities (phase one) and later adapted for primary care units (phase two). This study analyzed HCP experiences during training and implementation and identified barriers and facilitators. In-depth interviews and focus discussion groups were conducted 30 days after each training for a purposive random sample of 115 HCPs. Thematic analysis was employed using MAXQDA software, analyzing data through inductive and deductive coding. Analysis showed that following the initial training for higher-level facilities, some HCPs did not feel confident performing quantitative G6PD testing and prescribing the tafenoquine regimen. Modifications to the training in phase two resulted in an improvement in understanding the implementation process of the G6PD test and tafenoquine, as well as in the knowledge acquired by HCPs. Additionally, knowledge gaps were addressed through in situ training, peer communication via a messaging app, and educational materials. Training supported effective deployment of the new tools in Manaus and Porto Velho and increased awareness of the need for pharmacovigilance. A training approach for nationwide implementation of these tools was devised. Implementing quantitative G6PD testing and tafenoquine represents a significant shift in P. vivax malaria case management. Consistent engagement with HCPs is needed to overcome challenges in fully integrating these tools within the Brazilian health system.
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Affiliation(s)
- Alicia Santos
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Marcelo Brito
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
| | - Evellyn Silva
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Felipe Rocha
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
| | - Ana Oliveira
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
| | - Rafaela Dávila
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Hiran Gama
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | | | - Mena Paiva
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Djane Baía-Silva
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Vanderson Sampaio
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Patrícia Balieiro
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Rosilene Rufatto
- Centro de Pesquisa em Medicina Tropical de Rondônia (CEPEM), Porto Velho, Brazil
| | | | | | | | - Wuelton Monteiro
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Ana Arcanjo
- Fundação de Vigilância em Saúde, Manaus, Brazil
| | | | | | - Marcus Lacerda
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
- Instituto Leônidas & Maria Deane, Fiocruz, Manaus, Brazil
- University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Felipe Murta
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
- Instituto Leônidas & Maria Deane, Fiocruz, Manaus, Brazil
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Msellemu D, Tanner M, Yadav R, Moore SJ. Occupational exposure to malaria, leishmaniasis and arbovirus vectors in endemic regions: A systematic review. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2024; 6:100185. [PMID: 39027087 PMCID: PMC11252614 DOI: 10.1016/j.crpvbd.2024.100185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/26/2024] [Accepted: 06/01/2024] [Indexed: 07/20/2024]
Abstract
Vector-borne diseases, including dengue, leishmaniasis and malaria, may be more common among individuals whose occupations or behaviours bring them into frequent contact with these disease vectors outside of their homes. A systematic review was conducted to ascertain at-risk occupations and situations that put individuals at increased risk of exposure to these disease vectors in endemic regions and identify the most suitable interventions for each exposure. The review was conducted in accordance with PRISMA guidelines on articles published between 1945 and October 2021, searched in 16 online databases. The primary outcome was incidence or prevalence of dengue, leishmaniasis or malaria. The review excluded ecological and qualitative studies, abstracts only, letters, commentaries, reviews, and studies of laboratory-acquired infections. Studies were appraised, data extracted, and a descriptive analysis conducted. Bite interventions for each risk group were assessed. A total of 1170 articles were screened and 99 included. Malaria, leishmaniasis and dengue were presented in 47, 41 and 24 articles, respectively; some articles presented multiple conditions. The most represented populations were soldiers, 38% (43 of 112 studies); refugees and travellers, 15% (17) each; migrant workers, 12.5% (14); miners, 9% (10); farmers, 5% (6); rubber tappers and missionaries, 1.8% (2) each; and forest workers, 0.9% (1). Risk of exposure was categorised into round-the-clock or specific times of day/night dependent on occupation. Exposure to these vectors presents a critical and understudied concern for outdoor workers and mobile populations. When devising interventions to provide round-the-clock vector bite protection, two populations are considered. First, mobile populations, characterized by their high mobility, may find potential benefits in insecticide-treated clothing, though more research and optimization are essential. Treated clothing offers personal vector protection and holds promise for economically disadvantaged individuals, especially when enabling them to self-treat their clothing to repel vectors. Secondly, semi-permanent and permanent settlement populations can receive a combination of interventions that offer both personal and community protection, including spatial repellents, suitable for extended stays. Existing research is heavily biased towards tourism and the military, diverting attention and resources from vulnerable populations where these interventions are most required like refugee populations as well as those residing in sub-Saharan Africa.
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Affiliation(s)
- Daniel Msellemu
- Vector Control Product Testing Unit, Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Tanzania
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Rajpal Yadav
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
- Academy of Public Health Entomology, Udaipur, 313 002, India
| | - Sarah J. Moore
- Vector Control Product Testing Unit, Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Tanzania
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
- The Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Tengeru, Arusha, Tanzania
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Mak J, Sriudomporn S, Moss WJ, Patenaude BN. An Estimate Of The Return On Investment Of A Malaria Vaccine In 20 Sub-Saharan African Countries, 2021-30. Health Aff (Millwood) 2023; 42:1091-1099. [PMID: 37549331 DOI: 10.1377/hlthaff.2022.01328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Malaria is a leading global health problem that was responsible for an estimated 619,000 deaths worldwide in 2021. We modeled the return on investment (ROI) for the introduction and continuation of a four-dose malaria vaccine, RTS,S/AS01, from 2021 to 2030 in twenty sub-Saharan African countries supported by Gavi, the Vaccine Alliance. We used the Decade of Vaccine Economics benefits and costing outputs to calculate an ROI using health impact data modeled by the Swiss Tropical and Public Health Institute (hereafter "Swiss") and Imperial College London (hereafter "Imperial"). The Swiss estimates with a base vaccine price of US$7.00 resulted in an ROI of 0.42, and the Imperial impact estimates with the same base vaccine price resulted in an ROI of 2.30. Inclusion of the fifth seasonal dose for ten countries exhibiting high seasonal disease burden increased the Swiss ROI by 143 percent, to 1.02, and the Imperial ROI by 23.5 percent, to 2.84. To improve ROI, decision makers should continue to improve delivery platforms, decrease vaccine delivery costs, deliver the malaria vaccine in fewer doses, and provide access to vaccine resources.
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Affiliation(s)
- Joshua Mak
- Joshua Mak , Johns Hopkins University, Baltimore, Maryland
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Sadhewa A, Cassidy-Seyoum S, Acharya S, Devine A, Price RN, Mwaura M, Thriemer K, Ley B. A Review of the Current Status of G6PD Deficiency Testing to Guide Radical Cure Treatment for Vivax Malaria. Pathogens 2023; 12:pathogens12050650. [PMID: 37242320 DOI: 10.3390/pathogens12050650] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Plasmodium vivax malaria continues to cause a significant burden of disease in the Asia-Pacific, the Horn of Africa, and the Americas. In addition to schizontocidal treatment, the 8-aminoquinoline drugs are crucial for the complete removal of the parasite from the human host (radical cure). While well tolerated in most recipients, 8-aminoquinolines can cause severe haemolysis in glucose-6-phosphate dehydrogenase (G6PD) deficient patients. G6PD deficiency is one of the most common enzymopathies worldwide; therefore, the WHO recommends routine testing to guide 8-aminoquinoline based treatment for vivax malaria whenever possible. In practice, this is not yet implemented in most malaria endemic countries. This review provides an update of the characteristics of the most used G6PD diagnostics. We describe the current state of policy and implementation of routine point-of-care G6PD testing in malaria endemic countries and highlight key knowledge gaps that hinder broader implementation. Identified challenges include optimal training of health facility staff on point-of-care diagnostics, quality control of novel G6PD diagnostics, and culturally appropriate information and communication with affected communities around G6PD deficiency and implications for treatment.
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Affiliation(s)
- Arkasha Sadhewa
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
| | - Sarah Cassidy-Seyoum
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
| | - Sanjaya Acharya
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
| | - Angela Devine
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne 3010, Australia
- Centre for Health Policy, Melbourne School of Population and Global Health, University of Melbourne, Melbourne 3010, Australia
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX1 2JD, UK
| | - Muthoni Mwaura
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
| | - Kamala Thriemer
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
| | - Benedikt Ley
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
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5
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Abstract
Background Quantifying disease costs is critical for policymakers to set priorities, allocate resources, select control and prevention strategies, and evaluate the cost-effectiveness of interventions. Although malaria carries a very large disease burden, the availability of comprehensive and comparable estimates of malaria costs across endemic countries is scarce. Methods A literature review to summarize methodologies utilized to estimate malaria treatment costs was conducted to identify gaps in knowledge. Results Only 45 publications met the inclusion criteria. They utilize different methods, include distinct cost components, have varied geographical coverage (a country vs a city), include different periods in the analysis, and focus on specific parasite types or population groups (e.g., pregnant women). Conclusions Cost estimates currently available are not comparable, hindering broad statements on the costs of malaria, and constraining advocacy efforts towards investment in malaria control and elimination, particularly with the finance and development sectors of the government. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04303-6.
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Adderley J, Boulet C, McCann K, McHugh E, Ioannidis LJ, Yeoh LM. Advances in Plasmodium research, an update: highlights from the Malaria in Melbourne 2021 conference. Mol Biochem Parasitol 2022; 250:111487. [DOI: 10.1016/j.molbiopara.2022.111487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/05/2022] [Accepted: 05/18/2022] [Indexed: 11/28/2022]
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Maher SP, Vantaux A, Chaumeau V, Chua ACY, Cooper CA, Andolina C, Péneau J, Rouillier M, Rizopoulos Z, Phal S, Piv E, Vong C, Phen S, Chhin C, Tat B, Ouk S, Doeurk B, Kim S, Suriyakan S, Kittiphanakun P, Awuku NA, Conway AJ, Jiang RHY, Russell B, Bifani P, Campo B, Nosten F, Witkowski B, Kyle DE. Probing the distinct chemosensitivity of Plasmodium vivax liver stage parasites and demonstration of 8-aminoquinoline radical cure activity in vitro. Sci Rep 2021; 11:19905. [PMID: 34620901 PMCID: PMC8497498 DOI: 10.1038/s41598-021-99152-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 09/21/2021] [Indexed: 12/25/2022] Open
Abstract
Improved control of Plasmodium vivax malaria can be achieved with the discovery of new antimalarials with radical cure efficacy, including prevention of relapse caused by hypnozoites residing in the liver of patients. We screened several compound libraries against P. vivax liver stages, including 1565 compounds against mature hypnozoites, resulting in one drug-like and several probe-like hits useful for investigating hypnozoite biology. Primaquine and tafenoquine, administered in combination with chloroquine, are currently the only FDA-approved antimalarials for radical cure, yet their activity against mature P. vivax hypnozoites has not yet been demonstrated in vitro. By developing an extended assay, we show both drugs are individually hypnozonticidal and made more potent when partnered with chloroquine, similar to clinically relevant combinations. Post-hoc analyses of screening data revealed excellent performance of ionophore controls and the high quality of single point assays, demonstrating a platform able to support screening of greater compound numbers. A comparison of P. vivax liver stage activity data with that of the P. cynomolgi blood, P. falciparum blood, and P. berghei liver stages reveals overlap in schizonticidal but not hypnozonticidal activity, indicating that the delivery of new radical curative agents killing P. vivax hypnozoites requires an independent and focused drug development test cascade.
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Affiliation(s)
- Steven P Maher
- Center for Tropical and Emerging Global Diseases, University of Georgia, 500 DW Brooks Dr. Suite 370, Athens, GA, 30602, USA.
| | - Amélie Vantaux
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Victor Chaumeau
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 68/30 Bantung Rd., Mae Sot, Tak, 63110, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Oxford, UK
| | - Adeline C Y Chua
- Infectious Diseases Laboratories (ID Labs), Agency for Science, Technology and Research (A*STAR), Immunos, Biopolis, Singapore, 138648, Singapore
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Caitlin A Cooper
- Center for Tropical and Emerging Global Diseases, University of Georgia, 500 DW Brooks Dr. Suite 370, Athens, GA, 30602, USA
| | - Chiara Andolina
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 68/30 Bantung Rd., Mae Sot, Tak, 63110, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Oxford, UK
| | - Julie Péneau
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Mélanie Rouillier
- Medicines for Malaria Venture (MMV), Route de Pré-Bois 20, 1215, Geneva, Switzerland
| | - Zaira Rizopoulos
- Medicines for Malaria Venture (MMV), Route de Pré-Bois 20, 1215, Geneva, Switzerland
| | - Sivchheng Phal
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Eakpor Piv
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Chantrea Vong
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Sreyvouch Phen
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Chansophea Chhin
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Baura Tat
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Sivkeng Ouk
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Bros Doeurk
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Saorin Kim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia
| | - Sangrawee Suriyakan
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 68/30 Bantung Rd., Mae Sot, Tak, 63110, Thailand
| | - Praphan Kittiphanakun
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 68/30 Bantung Rd., Mae Sot, Tak, 63110, Thailand
| | - Nana Akua Awuku
- Center for Tropical and Emerging Global Diseases, University of Georgia, 500 DW Brooks Dr. Suite 370, Athens, GA, 30602, USA
| | - Amy J Conway
- Department of Global Health, College of Public Health, Center for Global Health and Infectious Disease Research, University of South Florida, 3720 Spectrum Blvd Suite 402, Tampa, FL, 33612, USA
| | - Rays H Y Jiang
- Department of Global Health, College of Public Health, Center for Global Health and Infectious Disease Research, University of South Florida, 3720 Spectrum Blvd Suite 402, Tampa, FL, 33612, USA
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Pablo Bifani
- Infectious Diseases Laboratories (ID Labs), Agency for Science, Technology and Research (A*STAR), Immunos, Biopolis, Singapore, 138648, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545, Singapore
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Brice Campo
- Medicines for Malaria Venture (MMV), Route de Pré-Bois 20, 1215, Geneva, Switzerland
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 68/30 Bantung Rd., Mae Sot, Tak, 63110, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Oxford, UK
| | - Benoît Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12201, Cambodia.
| | - Dennis E Kyle
- Center for Tropical and Emerging Global Diseases, University of Georgia, 500 DW Brooks Dr. Suite 370, Athens, GA, 30602, USA.
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Devine A, Battle KE, Meagher N, Howes RE, Dini S, Gething PW, Simpson JA, Price RN, Lubell Y. Global economic costs due to vivax malaria and the potential impact of its radical cure: A modelling study. PLoS Med 2021; 18:e1003614. [PMID: 34061843 PMCID: PMC8168905 DOI: 10.1371/journal.pmed.1003614] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 04/07/2021] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND In 2017, an estimated 14 million cases of Plasmodium vivax malaria were reported from Asia, Central and South America, and the Horn of Africa. The clinical burden of vivax malaria is largely driven by its ability to form dormant liver stages (hypnozoites) that can reactivate to cause recurrent episodes of malaria. Elimination of both the blood and liver stages of the parasites ("radical cure") is required to achieve a sustained clinical response and prevent ongoing transmission of the parasite. Novel treatment options and point-of-care diagnostics are now available to ensure that radical cure can be administered safely and effectively. We quantified the global economic cost of vivax malaria and estimated the potential cost benefit of a policy of radical cure after testing patients for glucose-6-phosphate dehydrogenase (G6PD) deficiency. METHODS AND FINDINGS Estimates of the healthcare provider and household costs due to vivax malaria were collated and combined with national case estimates for 44 endemic countries in 2017. These provider and household costs were compared with those that would be incurred under 2 scenarios for radical cure following G6PD screening: (1) complete adherence following daily supervised primaquine therapy and (2) unsupervised treatment with an assumed 40% effectiveness. A probabilistic sensitivity analysis generated credible intervals (CrIs) for the estimates. Globally, the annual cost of vivax malaria was US$359 million (95% CrI: US$222 to 563 million), attributable to 14.2 million cases of vivax malaria in 2017. From a societal perspective, adopting a policy of G6PD deficiency screening and supervision of primaquine to all eligible patients would prevent 6.1 million cases and reduce the global cost of vivax malaria to US$266 million (95% CrI: US$161 to 415 million), although healthcare provider costs would increase by US$39 million. If perfect adherence could be achieved with a single visit, then the global cost would fall further to US$225 million, equivalent to $135 million in cost savings from the baseline global costs. A policy of unsupervised primaquine reduced the cost to US$342 million (95% CrI: US$209 to 532 million) while preventing 2.1 million cases. Limitations of the study include partial availability of country-level cost data and parameter uncertainty for the proportion of patients prescribed primaquine, patient adherence to a full course of primaquine, and effectiveness of primaquine when unsupervised. CONCLUSIONS Our modelling study highlights a substantial global economic burden of vivax malaria that could be reduced through investment in safe and effective radical cure achieved by routine screening for G6PD deficiency and supervision of treatment. Novel, low-cost interventions for improving adherence to primaquine to ensure effective radical cure and widespread access to screening for G6PD deficiency will be critical to achieving the timely global elimination of P. vivax.
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Affiliation(s)
- Angela Devine
- Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Katherine E. Battle
- Institute for Disease Modeling, Seattle, Washington, United States of America
| | - Niamh Meagher
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
- Victorian Infectious Diseases Reference Laboratory Epidemiology Unit, Royal Melbourne Hospital, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Rosalind E. Howes
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
- Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Saber Dini
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter W. Gething
- Telethon Kids Institute, Perth Children’s Hospital, Nedlands, Western Australia, Australia
- Curtin University, Bentley, Western Australia, Australia
| | - Julie A. Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Ric N. Price
- Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
| | - Yoel Lubell
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
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Devine A, Howes RE, Price DJ, Moore KA, Ley B, Simpson JA, Dittrich S, Price RN. Cost-Effectiveness Analysis of Sex-Stratified Plasmodium vivax Treatment Strategies Using Available G6PD Diagnostics to Accelerate Access to Radical Cure. Am J Trop Med Hyg 2020; 103:394-403. [PMID: 32372747 PMCID: PMC7356471 DOI: 10.4269/ajtmh.19-0943] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Tafenoquine has been licensed for the single-dose radical cure of Plasmodium vivax in adults; however, it is only recommended in patients with > 70% of normal glucose-6-phosphate dehydrogenase (G6PD) activity. Because this may hinder widespread use, we investigated sex-based treatment strategies in which all adult patients are tested with a qualitative G6PD rapid diagnostic test (RDT). Glucose-6-phosphate dehydrogenase normal males are prescribed tafenoquine in all three strategies, whereas G6PD normal females are prescribed either a low-dose 14-day primaquine regimen (PQ14, total dose 3.5 mg/kg) or a high-dose 7-day primaquine regimen (PQ7, total dose 7 mg/kg), or referred to a healthcare facility for quantitative G6PD testing before prescribing tafenoquine. Patients testing G6PD deficient are prescribed a weekly course of primaquine for 8 weeks. We compared the cost-effectiveness of these three strategies to usual care in four countries using a decision tree model. Usual care in Ethiopia does not include radical cure, whereas Afghanistan, Indonesia, and Vietnam prescribe PQ14 without G6PD screening. The cost per disability-adjusted life-year (DALY) averted was expressed through incremental cost-effectiveness ratios (ICERs). Compared with usual care, the ICERs for a sex-based treatment strategy with PQ7 for females from a healthcare provider perspective were $127 per DALY averted in Vietnam, $466 in Ethiopia, $1,089 in Afghanistan, and $4,443 in Indonesia. The PQ14 and referral options cost more while averting fewer DALYs than PQ7. This study provides an alternative cost-effective mode of rolling out tafenoquine in areas where initial testing with only a G6PD RDT is feasible.
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Affiliation(s)
- Angela Devine
- Division of Global and Tropical Health, Menzies School of Health Research, Charles Darwin University, Darwin, Australia;,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia;,Address correspondence to Angela Devine, Division of Global and Tropical Health, Menisci School of Health Research, Charles Darwin University, P. O. Box 41096, Casuarina NT 0811, Australia. E-mail:
| | - Rosalind E. Howes
- Malaria and Fever Programme, Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland;,Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - David J. Price
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia;,Victorian Infectious Diseases Reference Laboratory Epidemiology Unit at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne and Royal Melbourne Hospital, Melbourne, Australia
| | - Kerryn A. Moore
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom;,Infection and Immunity, Murdoch Children’s Research Institute, Melbourne, Australia
| | - Benedikt Ley
- Division of Global and Tropical Health, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Julie A. Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Sabine Dittrich
- Malaria and Fever Programme, Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland;,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Ric N. Price
- Division of Global and Tropical Health, Menzies School of Health Research, Charles Darwin University, Darwin, Australia;,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom;,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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