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Mahapatra B, Mukherjee N, Khatoon S, Bhattacharya P, Das P, Bharti O, John D. Economic evaluations of neglected tropical diseases interventions in low- and middle-income countries: a systematic review protocol. JBI Evid Synth 2024:02174543-990000000-00283. [PMID: 38465423 DOI: 10.11124/jbies-23-00339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
OBJECTIVE The objective of this systematic review is to provide an overview of economic evaluation studies of interventions for neglected tropical diseases in low- and/or middle-income countries. INTRODUCTION The majority of people most susceptible to neglected tropical diseases reside in low- and middle-income countries and suffer significant economic impact due to these diseases. The World Health Organization suggests utilizing a systematic and cross-cutting approach with multiple interventions to lessen the neglected tropical disease burden. INCLUSION CRITERIA Studies will be eligible for inclusion if they include economic evaluations of interventions for neglected tropical diseases and are conducted in low- and/or middle-income country settings. METHODS A preliminary search of MEDLINE (PubMed) was undertaken using MeSH terms, such as neglected tropical disease, economic evaluation, therapeutics, low- and/or middle-income countries. Two reviewers will screen titles and abstracts independently, followed by a full-text review against the inclusion criteria. Disagreements will be resolved by discussion or with a third reviewer. To assess methodological quality, the JBI checklist for economic evaluations will be used. For economic evaluations, data will be extracted using the standardized JBI data extraction form. The Dominance Ranking Matrix will be used to summarize and compare the results of different types of economic evaluations. Cost per quality adjusted life year gained and cost per disability adjusted life year averted will be measures for economic evaluation. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach will be used to assess the certainty of economic evidence, such as resource use and costs. REVIEW REGISTRATION PROSPERO CRD42017070386.
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Affiliation(s)
- Biswajit Mahapatra
- Centre for Public Health Research, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
- Evidence Synthesis and Implementation for Indigenous Health: A JBI Affiliated Group, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
| | - Nirmalya Mukherjee
- Centre for Public Health Research, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
- Evidence Synthesis and Implementation for Indigenous Health: A JBI Affiliated Group, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
| | - Sajda Khatoon
- Centre for Public Health Research, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
- Evidence Synthesis and Implementation for Indigenous Health: A JBI Affiliated Group, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
| | - Paramita Bhattacharya
- Centre for Public Health Research, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
- Evidence Synthesis and Implementation for Indigenous Health: A JBI Affiliated Group, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
| | - Pritha Das
- Centre for Public Health Research, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
- Evidence Synthesis and Implementation for Indigenous Health: A JBI Affiliated Group, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
| | - Omesh Bharti
- State Institute of Health and Family Welfare, Department of Health & Family Welfare, Government of Himachal Pradesh, Shimla, Himachal Pradesh, India
| | - Denny John
- Evidence Synthesis and Implementation for Indigenous Health: A JBI Affiliated Group, Manbhum Ananda Ashram Nityananda Trust (MANT), Kolkata, West Bengal, India
- Faculty of Life and Allied Health Sciences, M.S. Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India
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Santos MCS, Oliveira GLD, Mingoti SA, Heller L. Sewerage as a protective factor for prevalence of hookworm infection in schoolchildren in Brazil: A multilevel ecological analysis of national prevalence surveys (1950-2018). THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 895:164621. [PMID: 37271392 DOI: 10.1016/j.scitotenv.2023.164621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/05/2023] [Accepted: 05/31/2023] [Indexed: 06/06/2023]
Abstract
INTRODUCTION The prevalence of hookworm infection in Brazil has decreased considerably in recent decades. However, there is no definitive consensus as to which changes have contributed to this reduction. A hypothesis is that improvements in environmental factors have contributed to lowering the parasite load and the level of host-parasite contact. METHODS This is an ecological study using unbalanced panel data from two Brazilian surveys (1947-1953 and 2010-2015), with municipalities as the analysis unit. The sample comprised 1428 municipalities, in which a total of 745,983 schoolchildren aged 7 to 14 were examined. Zero-inflated Poisson regression models, with fixed and random effects were estimated to evaluate the association of potential explanatory variables with the prevalence of hookworm infection at a significance level of 5 %. RESULTS We identified a significant decrease in the prevalence between the first and last analyzed periods (RR 0.096; CI 0.086-0.107); The following variables were found to have a protective effect: access to sanitary sewage systems (RR 0.984, CI 0.982-0.986), urbanization (RR 0.995, CI 0.993-0.997), and gross domestic product (RR 0.929, CI 0.912-0.945). CONCLUSION The findings of this study show a decrease in the prevalence of hookworm infections over six decades in schoolchildren in the Brazilian municipalities. Environmental, demographic, and economic factors were associated with this trend. A historical analysis indicates that interventions aimed at improving sanitation contributed to reducing the disease prevalence.
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Affiliation(s)
- Mariana Cristina Silva Santos
- Rene Rachou Institute (IRR), Oswaldo Cruz Foundation (FIOCRUZ), 1715 Augusto de Lima Ave, Barro Preto, Belo Horizonte, Minas Gerais 30190-009, Brazil.
| | - Guilherme Lopes de Oliveira
- Federal Center for Technological Education of Minas Gerais, 5253 Amazonas Ave, Nova Suiça, Belo Horizonte, Minas Gerais 30421169, Brazil.
| | - Sueli Aparecida Mingoti
- Federal University of Minas Gerais, 6627 Pres Antônio Carlos Ave, Pampulha, Belo Horizonte, Brazil
| | - Léo Heller
- Rachou Institute (IRR), Oswaldo Cruz Foundation (FIOCRUZ), 1715 Augusto de Lima Ave, Barro Preto, Belo Horizonte, Minas Gerais 30190-009, Brazil.
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Uzoegbo SC, Jackson LJ, Bloch SCM. A systematic review and quality appraisal of the economic evaluations of schistosomiasis interventions. PLoS Negl Trop Dis 2022; 16:e0010822. [PMID: 36223400 PMCID: PMC9591071 DOI: 10.1371/journal.pntd.0010822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 10/24/2022] [Accepted: 09/16/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Schistosomiasis is a neglected tropical disease (NTD) that affects over 230 million people in low and middle-income countries (LMICs) and can lead to long-term debilitating health effects. It is associated with impoverishment and has been prioritised by the World Health Organization for prevention, control and elimination. This systematic review aimed to identify and evaluate existing economic evaluations of interventions to tackle schistosomiasis. METHODOLOGY A comprehensive search strategy of four databases and additional hand-searching was employed on the 17th July 2020. The articles were screened and sorted using a two-stage classification system. Full economic evaluations published in English between 1st January 1998 and 17th July 2020 were included, and methodological quality was appraised using the international decision support initiative (iDSI), Phillips and Evers checklists. RESULTS Eighteen economic evaluations were identified, nine trial-based and nine model-based, with the majority focused on preventative chemotherapy. Schistosomiasis interventions were collectively found to be cost-effective, but the quantity and quality of studies were limited. The outcome measures and time-horizons utilised varied substantially making comparison difficult. The majority of papers failed to address equity and affordability. CONCLUSION Several methodological issues were highlighted which might have implications for optimal decision-making. Future research is needed to ensure the standardisation of methods, in order to ensure that scarce healthcare resources are focused on the most cost-effective programmes to tackle schistosomiasis and other NTDs.
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Affiliation(s)
- Sharon C. Uzoegbo
- Institute of Applied Health Research, University of Birmingham- College of Medical and Dental Sciences, Birmingham, United Kingdom
| | - Louise J. Jackson
- Institute of Applied Health Research, University of Birmingham- College of Medical and Dental Sciences, Birmingham, United Kingdom
- * E-mail:
| | - Sonja C. M. Bloch
- Institute of Applied Health Research, University of Birmingham- College of Medical and Dental Sciences, Birmingham, United Kingdom
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Widdicombe J, Basáñez MG, Entezami M, Jackson D, Larrieu E, Prada JM. The economic evaluation of Cystic echinococcosis control strategies focused on zoonotic hosts: A scoping review. PLoS Negl Trop Dis 2022; 16:e0010568. [PMID: 35797271 PMCID: PMC9262177 DOI: 10.1371/journal.pntd.0010568] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/07/2022] [Indexed: 12/29/2022] Open
Abstract
Background Cystic echinococcosis (CE) is a zoonotic neglected tropical disease (zNTD) which imposes considerable financial burden to endemic countries. The 2021–2030 World Health Organization’s roadmap on NTDs has proposed that intensified control be achieved in hyperendemic areas of 17 countries by 2030. Successful interventions for disease control, and the scale-up of programmes applying such interventions, rely on understanding the associated costs and relative return for investment. We conducted a scoping review of existing peer-reviewed literature on economic evaluations of CE control strategies focused on Echinococcus granulosus zoonotic hosts. Methodology/Principal findings Database searches of Scopus, PubMed, Web of Science, CABI Direct and JSTOR were conducted and comprehensively reviewed in March 2022, using predefined search criteria with no date, field or language restrictions. A total of 100 papers were initially identified and assessed for eligibility against strict inclusion and exclusion criteria, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. Bibliography review of included manuscripts was used to identify additional literature. Full review of the final manuscript selection (n = 9) was performed and cost data for control interventions were extracted. Conclusions/Significance There are very little published data pertaining to the cost and cost effectiveness of CE control interventions targeting its zoonotic hosts. Data given for costs are often incomplete, thus we were unable to perform an economic analysis and cost effectiveness study, highlighting a pressing need for this information. There is much scope for future work in this area. More detailed information and disaggregated costings need to be collected and made available. This would increase the accuracy of any cost-effective analyses to be performed and allow for a greater understanding of the opportunity cost of healthcare decisions and resource allocation by stakeholders and policy makers for effective and cost-effective CE control. Cystic echinococcosis (CE) is a zoonotic neglected tropical disease which predominantly affects poor pastoral communities globally. The parasite cycles between farm dogs and livestock, and is associated with livestock farming and feeding of infected offal to dogs. Although no noticeable clinical signs are seen in livestock, some production losses, such as reduced milk yield and live weight gain may be observed, and offal condemnation at slaughter is common. The disease can also affect people, due to accidental ingestion of parasite eggs on contaminated food and contact with dogs. Human morbidity and mortality occur due to cyst formation in body organs, exerting a substantial health and financial burden to the health sector of affected countries. Control interventions to reduce CE transmission include sheep vaccination and dog deworming. Long-term control programmes are often expensive, and the true costs of such programmes poorly documented. This scoping review aims to examine published literature on the costs of CE control in zoonotic hosts and report detailed costs of individual elements of a control programme, thereby furthering our understanding of the true economic cost of CE control.
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Affiliation(s)
- Jo Widdicombe
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- * E-mail:
| | - María-Gloria Basáñez
- MRC Centre for Global Infectious Disease Analysis and London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Mahbod Entezami
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Daniel Jackson
- Surrey Health Economics Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Edmundo Larrieu
- Universidad Nacional de Rio Negro, Choele Choel, Rio Negro, Argentina
| | - Joaquín M. Prada
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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Mow M, Thean LJ, Parnaby M, Mani J, Rafai E, Sahukhan A, Kama M, Tuicakau M, Kado J, Romani L, Engelman D, Whitfeld M, Kaldor J, Steer A, Carvalho N. Costs of mass drug administration for scabies in Fiji. PLoS Negl Trop Dis 2022; 16:e0010147. [PMID: 35113888 PMCID: PMC8846527 DOI: 10.1371/journal.pntd.0010147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 02/15/2022] [Accepted: 01/05/2022] [Indexed: 12/03/2022] Open
Abstract
In 2019, the Murdoch Children’s Research Institute in partnership with the Fiji Ministry of Health and Medical Services carried out an integrated mass drug administration (MDA) for the treatment of scabies and lymphatic filariasis in the Northern Division of Fiji (population estimate 131,914). We conducted a retrospective micro-costing exercise focused on the cost of scabies control in order to inform budgeting and policy decision making in an endemic setting. We collected detailed information on financial and economic costs incurred by both parties during the course of the MDA campaign (April 2018 to July 2019). We also conducted interviews with personnel involved in the financial administration of the MDA campaign. The economic cost of delivering two doses of ivermectin was US$4.88 per person. The cost of donated drugs accounted for 36.3% of total MDA costs. In this first large-scale MDA for the public health control of scabies, the estimated cost of delivering MDA per person for scabies was considerably more expensive than the costs reported for other neglected tropical diseases. The important cost drivers included the remuneration of health care workers who were extensively involved in the campaign, coverage of hard-to-reach, mainly rural populations and the two-dose regimen of ivermectin. These results highlight the importance of these cost determinants and can be used to plan current and future MDA programs. Scabies poses a significant burden on both health and economic systems. The Global Burden of Disease estimated that this skin disease affects more than 200 million people globally. However, the economic burden of scabies has not been studied widely and there are limited data on the cost of treating scabies in highly endemic areas. We conducted a costing study of a mass drug administration (MDA) program in the Northern Division of Fiji (population of 131,914). We collected financial and economic costs of administering ivermectin and permethrin to the whole of the Northern Division population in order to estimate the per capita cost of delivering MDA. The costs of MDA for scabies in Fiji were higher than those estimated in previous studies of MDA for other neglected tropical diseases. The study highlights significant cost components of implementing a large-scale MDA and provides key insights for the design and implementation of future MDA programs for scabies. It also adds to the general knowledge in understanding cost inputs and estimating the overall cost-effectiveness of this public health intervention.
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Affiliation(s)
- Maria Mow
- Tropical Diseases Group, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
- * E-mail:
| | - Li Jun Thean
- Tropical Diseases Group, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Matthew Parnaby
- Tropical Diseases Group, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
| | - Jyotishna Mani
- Tropical Diseases Group, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
| | - Eric Rafai
- Ministry of Health and Medical Services, Suva, Fiji
| | | | - Mike Kama
- Ministry of Health and Medical Services, Suva, Fiji
| | | | - Joseph Kado
- Ministry of Health and Medical Services, Suva, Fiji
- Wesfarmers Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Lucia Romani
- Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Daniel Engelman
- Tropical Diseases Group, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
- Melbourne Children’s Global Health, Melbourne Children’s Campus, The Royal Children’s Hospital, Melbourne, Victoria, Australia
| | - Margot Whitfeld
- Department of Dermatology, St. Vincent’s Hospital, Sydney, New South Wales, Australia
- School of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - John Kaldor
- Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Andrew Steer
- Tropical Diseases Group, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
- Melbourne Children’s Global Health, Melbourne Children’s Campus, The Royal Children’s Hospital, Melbourne, Victoria, Australia
| | - Natalie Carvalho
- School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
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Agboraw E, Sosu F, Dean L, Siakeh A, Thomson R, Kollie K, Worrall E. Factors influencing mass drug administration adherence and community drug distributor opportunity costs in Liberia: a mixed-methods approach. Parasit Vectors 2021; 14:557. [PMID: 34711278 PMCID: PMC8555123 DOI: 10.1186/s13071-021-05058-w] [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: 02/09/2021] [Accepted: 10/07/2021] [Indexed: 11/23/2022] Open
Abstract
Background Preventive chemotherapy delivered via mass drug administration (MDA) is essential for the control of neglected tropical diseases (NTDs), including lymphatic filariasis (LF), schistosomiasis and onchocerciasis. Successful MDA relies heavily on community drug distributor (CDD) volunteers as the interface between households and the health system. This study sought to document and analyse demand-side (households) and supply-side (health system) factors that affect MDA delivery in Liberia. Methods Working in two purposively selected counties, we conducted a household MDA access and adherence survey; a CDD survey to obtain information on direct and opportunity costs associated with MDA work; an observational survey of CDDs; and key informant surveys (KIS) with community-level health workers. Data from the CDD survey and Liberian minimum wage rates were used to calculate the opportunity cost of CDD participation per MDA round. The observational data were used to calculate the time spent on individual household-level tasks and CDD time costs per house visited. KIS data on the organisation and management of the MDA in the communities, and researcher reflections of open-ended survey responses were thematically analysed to identify key demand- and supply-side challenges. Results More respondents were aware of MDA than NTD in both counties. In Bong, 39% (103/261) of respondents reported taking the MDA tablet in the last round, with “not being informed” as the most important reason for non-adherence. In Maryland, 56% (147/263) reported taking MDA with “being absent” at the time of distribution being important for non-adherence. The mean cost per CDD of participating in the MDA round was −$11.90 (median $5.04, range −$169.62 to $30.00), and the mean time per household visited was 17.14 min which equates to a mean opportunity cost of $0.03 to $0.05 per household visited. Thematic analysis identified challenges, including shortages of and delays in medicine availability; CDD frustration over costs; reporting challenges; and household concerns about drug side effects. Conclusions Improved adherence to MDA and subsequent elimination of NTDs in Liberia would be supported by an improved medicine supply chain, financial compensation for CDDs, improved training, healthcare workforce strengthening, greater community involvement, capacity building, and community awareness. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-05058-w.
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Affiliation(s)
- Efundem Agboraw
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Street, Liverpool, L3 5 QA, UK.
| | - Fred Sosu
- University of Liberia, Pacific Institute for Research and Evaluation (UL-PIRE), Capitol Hill, Monrovia, Liberia
| | - Laura Dean
- Department of International Public Health, Liverpool School of Tropical Medicine, Pembroke Street, Liverpool, L3 5 QA, UK
| | - Alice Siakeh
- University of Liberia, Pacific Institute for Research and Evaluation (UL-PIRE), Capitol Hill, Monrovia, Liberia
| | - Rachael Thomson
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Street, Liverpool, L3 5 QA, UK
| | - Karsor Kollie
- Ministry of Health, SKD Boulevard, Monrovia, Liberia
| | - Eve Worrall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Street, Liverpool, L3 5 QA, UK
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Profiro de Oliveira JH, Arruda IES, Izak Ribeiro de Araújo J, Chaves LL, de La Rocca Soares MF, Soares-Sobrinho JL. Why do few drug delivery systems to combat neglected tropical diseases reach the market? An analysis from the technology's stages. Expert Opin Ther Pat 2021; 32:89-114. [PMID: 34424127 DOI: 10.1080/13543776.2021.1970746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Many drugs used to combat schistosomiasis, Chagas disease, and leishmaniasis (SCL) have clinical limitations such as: high toxicity to the liver, kidneys and spleen; reproductive, gastrointestinal, and heart disorders; teratogenicity. In this sense, drug delivery systems (DDSs) have been described in the literature as a viable option for overcoming the limitations of these drugs. An analysis of the level of development (TRL) of patents can help in determine the steps that must be taken for promising technologies to reach the market. AREAS COVERED This study aimed to analyze the stage of development of DDSs for the treatment of SCL described in patents. In addition, we try to understand the main reasons why many DDSs do not reach the market. In this study, we examined DDSs for drugs indicated by WHO and treatment of SCL, by performing a search for patents. EXPERT OPINION In this present work we provide arguments that support the hypothesis that there is a lack of integration between academia and industry to finance and continue research, especially the development of clinical studies. We cite the translational research consortia as the potential alternative for developing DDSs to combat NTDs.
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Affiliation(s)
| | | | | | - Luise Lopes Chaves
- Department of Pharmacy, Federal University of Pernambuco, Recife, Recife-Pernambuco
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Ackley C, Elsheikh M, Zaman S. Scoping review of Neglected Tropical Disease Interventions and Health Promotion: A framework for successful NTD interventions as evidenced by the literature. PLoS Negl Trop Dis 2021; 15:e0009278. [PMID: 34228729 PMCID: PMC8321407 DOI: 10.1371/journal.pntd.0009278] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 07/29/2021] [Accepted: 02/26/2021] [Indexed: 11/19/2022] Open
Abstract
Background Neglected Tropical Diseases (NTDs) affect more than one billion people globally. A Public Library of Science (PLOS) journal dedicated to NTDs lists almost forty NTDs, while the WHO prioritises twenty NTDs. A person can be affected by more than one disease at the same time from a range of infectious and non-infectious agents. Many of these diseases are preventable, and could be eliminated with various public health, health promotion and medical interventions. This scoping review aims to determine the extent of the body of literature on NTD interventions and health promotion activities, and to provide an overview of their focus while providing recommendations for best practice going forward. This scoping review includes both the identification of relevant articles through the snowball method and an electronic database using key search terms. A two-phased screening process was used to assess the relevance of studies identified in the search–an initial screening review followed by data characterization using the Critical Appraisal Skills Program (CASP). Studies were eligible for inclusion if they broadly described the characteristics, methods, and approaches of (1) NTD interventions and/or (2) community health promotion. Principal findings 90 articles met the CASP criteria partially or fully and then underwent a qualitative synthesis to be included in the review. 75 articles specifically focus on NTD interventions and approaches to their control, treatment, and elimination, while 15 focus specifically on health promotion and provide a grounding in health promotion theories and perspectives. 29 of the articles provided a global perspective to control, treatment, or elimination of NTDs through policy briefs or literature reviews. 19 of the articles focused on providing strategies for NTDs more generally while 12 addressed multiple NTDs or their interaction with other infectious diseases. Of the 20 NTDs categorized by the WHO and the expanded NTD list identified by PLOS NTDs, several NTDs did not appear in the database search on NTD interventions and health promotion, including yaws, fascioliasis, and chromoblastomycosis. Conclusions Based on the literature we have identified the four core components of best practices including programmatic interventions, multi sectoral and multi-level interventions, adopting a social and ecological model and clearly defining ‘community.’ NTD interventions tend to centre on mass drug administration (MDA), particularly because NTDs were branded as such based on their being amenable to MDA. However, there remains a need for intervention approaches that also include multiple strategies that inform a larger multi-disease and multi-sectoral programme. Many NTD strategies include a focus on WASH and should also incorporate the social and ecological determinants of NTDs, suggesting a preventative and systems approach to health, not just a treatment-based approach. Developing strong communities and incorporating social rehabilitation at the sublocation level (e.g. hospital) could benefit several NTDs and infectious diseases through a multi-disease, multi-sectoral, and multi-lateral approach. Finally, it is important the ‘community’ is clearly defined in each intervention, and that community members are included in intervention activities and viewed as assets to interventions. Neglected Tropical Diseases (NTDs) affect more than one billion people globally. A person can be affected by more than one disease at the same time. Many of these diseases are preventable, and could be eliminated with various public health, health promotion and medical interventions. This scoping review aims to determine the extent of the body of literature on NTD interventions and health promotion activities, and to provide an overview of their focus while providing recommendations for best practice going forward. Through a database search and by identifying appropriate literature 75 articles were identified that specifically focus on NTD interventions and approaches to their control, treatment, and elimination, while 15 focus specifically on health promotion and provide a grounding in health promotion theories and perspectives. Based on the literature we have identified the four core components of best practices including programmatic interventions, multi sectoral and multi-level interventions, adopting a social and ecological model and clearly defining ‘community.’
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Affiliation(s)
- Caroline Ackley
- Global Health and Infection Department, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
- * E-mail:
| | | | - Shahaduz Zaman
- Global Health and Infection Department, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
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Bartsch SM, O'Shea KJ, Wedlock PT, Ferguson MC, Siegmund SS, Lee BY. Potential Clinical and Economic Value of Norovirus Vaccination in the Community Setting. Am J Prev Med 2021; 60:360-368. [PMID: 33516583 PMCID: PMC8415104 DOI: 10.1016/j.amepre.2020.10.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/04/2020] [Accepted: 10/30/2020] [Indexed: 12/20/2022]
Abstract
INTRODUCTION With norovirus vaccine candidates currently under development, now is the time to identify the vaccine characteristics and implementation thresholds at which vaccination becomes cost effective and cost saving in a community setting. METHODS In 2020, a norovirus transmission, clinical, and economics computational simulation model representing different U.S. population segments was developed to simulate the spread of norovirus and the potential impact of vaccinating children aged <5 years and older adults (aged ≥65 years). RESULTS Compared with no vaccination, vaccinating preschool-aged children averted 8%-72% of symptomatic norovirus cases in a community, whereas vaccinating older adults averted 2%-29% of symptomatic cases (varying with vaccine efficacy [25%-75%] and vaccination coverage [10%-80%]). Vaccination with a 25% vaccine efficacy was cost effective (incremental cost-effectiveness ratio ≤$50,000 per quality-adjusted life year) when vaccination cost ≤$445 and cost saving at ≤$370 when vaccinating preschool-aged children and ≤$42 and ≤$30, respectively, when vaccinating older adults. With a 50% vaccine efficacy, vaccination was cost effective when it cost ≤$1,190 and cost saving at ≤$930 when vaccinating preschool-aged children and ≤$110 and ≤$64, respectively, when vaccinating older adults. These cost thresholds (cost effective and cost saving, respectively) further increased with a 75% vaccine efficacy to ≤$1,600 and ≤$1,300 for preschool-aged children and ≤$165 and ≤$100 for older adults. CONCLUSIONS This study outlines thresholds at which a norovirus vaccine would be cost effective and cost saving in the community when vaccinating children aged <5 years and older adults. Establishing these thresholds can help provide decision makers with targets to consider when developing and implementing a norovirus vaccine.
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Affiliation(s)
- Sarah M Bartsch
- Public Health Informatics, Computational, and Operations Research (PHICOR), Graduate School of Public Health and Health Policy, City University of New York, New York City, New York
| | - Kelly J O'Shea
- Public Health Informatics, Computational, and Operations Research (PHICOR), Graduate School of Public Health and Health Policy, City University of New York, New York City, New York
| | - Patrick T Wedlock
- Public Health Informatics, Computational, and Operations Research (PHICOR), Graduate School of Public Health and Health Policy, City University of New York, New York City, New York
| | - Marie C Ferguson
- Public Health Informatics, Computational, and Operations Research (PHICOR), Graduate School of Public Health and Health Policy, City University of New York, New York City, New York
| | - Sheryl S Siegmund
- Public Health Informatics, Computational, and Operations Research (PHICOR), Graduate School of Public Health and Health Policy, City University of New York, New York City, New York
| | - Bruce Y Lee
- Public Health Informatics, Computational, and Operations Research (PHICOR), Graduate School of Public Health and Health Policy, City University of New York, New York City, New York.
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10
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Salari P, Fürst T, Knopp S, Rollinson D, Kabole F, Khamis MI, Omar MA, Bacon O, Ali SM, Utzinger J, Tediosi F. Financial Costs of the Zanzibar Elimination of Schistosomiasis Transmission Project. Am J Trop Med Hyg 2020; 103:2260-2267. [PMID: 32996446 PMCID: PMC7695112 DOI: 10.4269/ajtmh.20-0252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
We estimated the financial costs of different interventions against urogenital schistosomiasis, implemented by the Zanzibar Elimination of Schistosomiasis Transmission (ZEST) project, on Pemba and Unguja islands, Tanzania. We used available data on project activities, resources used, and costs reported in the accounting information systems of ZEST partners. The costs were estimated for all the activities related to snail control, behavior change interventions, the impact assessment surveys, and management of the whole program. Costs are presented in US$ for the full duration of the ZEST project from 2011/2012 to 2017. The total financial costs of implementing snail control activities over 5 years, excluding the costs for donated Bayluscide, were US$55,796 on Pemba and US$73,581 on Unguja, mainly driven by personnel costs. The total financial costs of implementing behavior change activities were US$109,165 on Pemba and US$155,828 on Unguja, with costs for personnel accounting for 47% on Pemba and 69% on Unguja. Costs of implementing biannual mass drug administration refer to the estimated 2.4 million treatments provided on Pemba over 4 years (2013–2016), and do not include the costs of donated praziquantel. The total cost per provided treatment was, on average, US$0.21. This study showed the value of exploiting administrative data to estimate costs of major global health interventions. It also provides an evidence base for financial costs and main cost drivers of implementing multiple combinations of intervention sets that inform decisions regarding the feasibility and affordability of implementing schistosomiasis control and elimination strategies.
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Affiliation(s)
- Paola Salari
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Thomas Fürst
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Stefanie Knopp
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Fatma Kabole
- Neglected Diseases Program, Zanzibar Ministry of Health, Zanzibar, Tanzania
| | - Mohammed I Khamis
- Neglected Diseases Program, Zanzibar Ministry of Health, Zanzibar, Tanzania
| | - Mussa A Omar
- Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania
| | | | - Said M Ali
- Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania
| | - Jürg Utzinger
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Fabrizio Tediosi
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
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11
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Bartsch SM, Stokes-Cawley OJ, Buekens P, Asti L, Bottazzi ME, Strych U, Wedlock PT, Mitgang EA, Meymandi S, Falcon-Lezama JA, Hotez PJ, Lee BY. The potential economic value of a therapeutic Chagas disease vaccine for pregnant women to prevent congenital transmission. Vaccine 2020; 38:3261-3270. [PMID: 32171575 DOI: 10.1016/j.vaccine.2020.02.078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 02/21/2020] [Accepted: 02/26/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Currently, there are no solutions to prevent congenital transmission of Chagas disease during pregnancy, which affects 1-40% of pregnant women in Latin America and is associated with a 5% transmission risk. With therapeutic vaccines under development, now is the right time to determine the economic value of such a vaccine to prevent congenital transmission. METHODS We developed a computational decision model that represented the clinical outcomes and diagnostic testing strategies for an infant born to a Chagas-positive woman in Mexico and evaluated the impact of vaccination. RESULTS Compared to no vaccination, a 25% efficacious vaccine averted 125 [95% uncertainty interval (UI): 122-128] congenital cases, 1.9 (95% UI: 1.6-2.2) infant deaths, and 78 (95% UI: 66-91) DALYs per 10,000 infected pregnant women; a 50% efficacious vaccine averted 251 (95% UI: 248-254) cases, 3.8 (95% UI: 3.6-4.2) deaths, and 160 (95% UI: 148-171) DALYs; and a 75% efficacious vaccine averted 376 (95% UI: 374-378) cases, 5.8 (95% UI: 5.5-6.1) deaths, and 238 (95% UI: 227-249) DALYs. A 25% efficacious vaccine was cost-effective (incremental cost-effectiveness ratio <3× Mexico's gross domestic product per capita, <$29,698/DALY averted) when the vaccine cost ≤$240 and ≤$310 and cost-saving when ≤$10 and ≤$80 from the third-party payer and societal perspectives, respectively. A 50% efficacious vaccine was cost-effective when costing ≤$490 and ≤$615 and cost-saving when ≤$25 and ≤$160, from the third-party payer and societal perspectives, respectively. A 75% efficacious vaccine was cost-effective when ≤$720 and ≤$930 and cost-saving when ≤$40 and ≤$250 from the third-party payer and societal perspectives, respectively. Additionally, 13-42 fewer infants progressed to chronic disease, saving $0.41-$1.21 million to society. CONCLUSION We delineated the thresholds at which therapeutic vaccination of Chagas-positive pregnant women would be cost-effective and cost-saving, providing economic guidance for decision-makers to consider when developing and bringing such a vaccine to market.
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Affiliation(s)
- Sarah M Bartsch
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, 55 W 125th Street, New York City, NY 10027, USA
| | - Owen J Stokes-Cawley
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, 55 W 125th Street, New York City, NY 10027, USA
| | - Pierre Buekens
- Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - Lindsey Asti
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, 55 W 125th Street, New York City, NY 10027, USA
| | - Maria Elena Bottazzi
- National School of Tropical Medicine and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113 Houston, TX 77030, USA
| | - Ulrich Strych
- National School of Tropical Medicine and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113 Houston, TX 77030, USA
| | - Patrick T Wedlock
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, 55 W 125th Street, New York City, NY 10027, USA
| | - Elizabeth A Mitgang
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, 55 W 125th Street, New York City, NY 10027, USA
| | - Sheba Meymandi
- Center of Excellence for Chagas Disease at Olive View-UCLA Medical Center, 14445 Olive View Drive, Sylmar, CA 91342, USA
| | - Jorge Abelardo Falcon-Lezama
- Carlos Slim Foundation, Lago Zurich 245, Piso 20. Ampliación Granada, Del. Miguel Hidalgo, C.P. 11529 Ciudad de México, Mexico
| | - Peter J Hotez
- National School of Tropical Medicine and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113 Houston, TX 77030, USA
| | - Bruce Y Lee
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, 55 W 125th Street, New York City, NY 10027, USA.
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12
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Bartsch SM, Asti L, Stokes-Cawley OJ, Sim SY, Bottazzi ME, Hotez PJ, Lee BY. The Potential Economic Value of a Zika Vaccine for a Woman of Childbearing Age. Am J Prev Med 2020; 58:370-377. [PMID: 31980305 DOI: 10.1016/j.amepre.2019.10.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 10/20/2019] [Accepted: 10/21/2019] [Indexed: 11/17/2022]
Abstract
INTRODUCTION With Zika vaccine candidates under development and women of childbearing age being the primary target population, now is the time to map the vaccine (e.g., efficacy and duration of protection) and vaccination (e.g., cost) characteristic thresholds at which vaccination becomes cost effective, highly cost effective, and cost saving. METHODS A Markov model was developed (to represent 2019 circumstances, US$ and INT$, Region of the Americas) to simulate a woman of childbearing age and the potential risk and clinical course of a Zika infection. RESULTS Compared with no vaccination, vaccination was cost effective (incremental cost-effectiveness ratio: US$1,254-$82,900/disability-adjusted life years averted) when the risk of infection was ≥0.05%-0.08% (varying with country income), vaccine efficacy was ≥25%, and vaccination cost was US$1-$7,500 (INT$5-$10,000 depending on country income level). Vaccination was dominant (i.e., saved costs and provided beneficial health effects) when the infection risk was ≥0.1% for a vaccine efficacy ≥75% and when the infection risk was ≥0.5% for a vaccine efficacy ≥25%, for scenarios where vaccination conferred a 1-year duration of protection and cost ≤$200. In some cases, the vaccine was cost effective when the risk was as low as 0.015%, the cost was as high as $7,500 (INT$10,000), the efficacy was as low as 25%, and the duration of protection was 1 year. CONCLUSIONS The thresholds at which vaccination becomes cost effective and cost saving can provide targets for Zika vaccine development and implementation.
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Affiliation(s)
- Sarah M Bartsch
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, New York City, New York
| | - Lindsey Asti
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, New York City, New York
| | - Owen J Stokes-Cawley
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, New York City, New York
| | - So Yoon Sim
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, New York City, New York
| | - Maria Elena Bottazzi
- National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Baylor College of Medicine, Houston, Texas; Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas
| | - Peter J Hotez
- National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Baylor College of Medicine, Houston, Texas; Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas
| | - Bruce Y Lee
- Public Health Informatics, Computational, and Operations Research (PHICOR), City University of New York, New York City, New York.
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13
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Sharma S, Smith ME, Reimer J, O'Brien DB, Brissau JM, Donahue MC, Carter CE, Michael E. Economic performance and cost-effectiveness of using a DEC-salt social enterprise for eliminating the major neglected tropical disease, lymphatic filariasis. PLoS Negl Trop Dis 2019; 13:e0007094. [PMID: 31260444 PMCID: PMC6625731 DOI: 10.1371/journal.pntd.0007094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 07/12/2019] [Accepted: 06/06/2019] [Indexed: 01/01/2023] Open
Abstract
Background Salt fortified with the drug, diethylcarbamazine (DEC), and introduced into a competitive market has the potential to overcome the obstacles associated with tablet-based Lymphatic Filariasis (LF) elimination programs. Questions remain, however, regarding the economic viability, production capacity, and effectiveness of this strategy as a sustainable means to bring about LF elimination in resource poor settings. Methodology and principal findings We evaluated the performance and effectiveness of a novel social enterprise-based approach developed and tested in Léogâne, Haiti, as a strategy to sustainably and cost-efficiently distribute DEC-medicated salt into a competitive market at quantities sufficient to bring about the elimination of LF. We undertook a cost-revenue analysis to evaluate the production capability and financial feasibility of the developed DEC salt social enterprise, and a modeling study centered on applying a dynamic mathematical model localized to reflect local LF transmission dynamics to evaluate the cost-effectiveness of using this intervention versus standard annual Mass Drug Administration (MDA) for eliminating LF in Léogâne. We show that the salt enterprise because of its mixed product business strategy may have already reached the production capacity for delivering sufficient quantities of edible DEC-medicated salt to bring about LF transmission in the Léogâne study setting. Due to increasing revenues obtained from the sale of DEC salt over time, expansion of its delivery in the population, and greater cumulative impact on the survival of worms leading to shorter timelines to extinction, this strategy could also represent a significantly more cost-effective option than annual DEC tablet-based MDA for accomplishing LF elimination. Significance A social enterprise approach can offer an innovative market-based strategy by which edible salt fortified with DEC could be distributed to communities both on a financially sustainable basis and at sufficient quantity to eliminate LF. Deployment of similarly fashioned intervention strategies would improve current efforts to successfully accomplish the goal of LF elimination, particularly in difficult-to-control settings. With less than three years remaining for meeting the initial 2020 target set by WHO for accomplishing the global elimination of Lymphatic Filariasis (LF), concerns are emerging regarding the feasibility of meeting this goal using the current tablet-based Mass Drug Administration strategy. Salt fortified with the antifilarial drug, diethylcarbamazine (DEC), could offer an intervention that avoids many of the barriers connected with tablet-based elimination programs. We analyzed the economic performance and cost-effectiveness of a novel DEC-salt social enterprise developed and tested in Léogâne arrondissement, Haiti, as a particularly significant strategy for accomplishing sustainable LF elimination in such complex settings. We show that because of increasing revenue from the sale of the DEC salt over time, expansion of its delivery in the population, and the adverse effect of continuous consumption of the drug on worms, the delivery of DEC through a salt enterprise can represent a significantly more cost-effective option than annual DEC tablet-based MDA for accomplishing LF elimination in settings, like Léogâne. We indicate that development of policy and research into how to deploy similarly-fashioned interventions, or work with the salt industry to increase population use of medicated salt, would improve present efforts to successfully accomplish the elimination of LF.
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Affiliation(s)
- Swarnali Sharma
- Department of Biological Sciences, University of Notre Dame, Galvin Life Science Center, Notre Dame, IN, United States of America
| | - Morgan E Smith
- Department of Biological Sciences, University of Notre Dame, Galvin Life Science Center, Notre Dame, IN, United States of America
| | - James Reimer
- Grosse Pointe Park, MI, United States of America
| | | | - Jean M Brissau
- College of Science, University of Notre Dame, Notre Dame, IN, United States of America
| | - Marie C Donahue
- Eck Institute of Global Health, University of Notre Dame, Notre Dame, IN, United States of America
| | - Clarence E Carter
- College of Science, University of Notre Dame, Notre Dame, IN, United States of America
| | - Edwin Michael
- Department of Biological Sciences, University of Notre Dame, Galvin Life Science Center, Notre Dame, IN, United States of America
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14
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Saccoliti F, Madia VN, Tudino V, De Leo A, Pescatori L, Messore A, De Vita D, Scipione L, Brun R, Kaiser M, Mäser P, Calvet CM, Jennings GK, Podust LM, Pepe G, Cirilli R, Faggi C, Di Marco A, Battista MR, Summa V, Costi R, Di Santo R. Design, Synthesis, and Biological Evaluation of New 1-(Aryl-1 H-pyrrolyl)(phenyl)methyl-1 H-imidazole Derivatives as Antiprotozoal Agents. J Med Chem 2019; 62:1330-1347. [PMID: 30615444 DOI: 10.1021/acs.jmedchem.8b01464] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have designed and synthesized a series of new imidazole-based compounds structurally related to an antiprotozoal agent with nanomolar activity which we identified recently. The new analogues possess micromolar activities against Trypanosoma brucei rhodesiense and Leishmania donovani and nanomolar potency against Plasmodium falciparum. Most of the analogues displayed IC50 within the low nanomolar range against Trypanosoma cruzi, with very high selectivity toward the parasite. Discussion of structure-activity relationships and in vitro biological data for the new compounds are provided against a number of different protozoa. The mechanism of action for the most potent derivatives (5i, 6a-c, and 8b) was assessed by a target-based assay using recombinant T. cruzi CYP51. Bioavailability and efficacy of selected hits were assessed in a T. cruzi mouse model, where 6a and 6b reduced parasitemia in animals >99% following intraperitoneal administration of 25 mg/kg/day dose for 4 consecutive days.
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Affiliation(s)
- Francesco Saccoliti
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Valentina Noemi Madia
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Valeria Tudino
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Alessandro De Leo
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Luca Pescatori
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Antonella Messore
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Daniela De Vita
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Luigi Scipione
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Reto Brun
- Swiss Tropical and Public Health Institute , Socinstrasse 57 , CH-4002 Basel , Switzerland
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute , Socinstrasse 57 , CH-4002 Basel , Switzerland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute , Socinstrasse 57 , CH-4002 Basel , Switzerland
| | - Claudia M Calvet
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States.,Laboratório de Ultraestrutura Celular , Instituto Oswaldo Cruz (IOC), FIOCRUZ, Rio de Janeiro , Rio de Janeiro 21040-360 , Brazil
| | - Gareth K Jennings
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Larissa M Podust
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Giacomo Pepe
- Dipartimento di Farmacia , Università di Salerno , Via Giovanni Paolo II 132 , I-84084 Fisciano , Salerno , Italy
| | - Roberto Cirilli
- Centro Nazionale per il Controllo e la Valutazione dei Farmaci , Istituto Superiore di Sanita , Viale Regina Elena 299 , I-00161 Rome , Italy
| | - Cristina Faggi
- Dipartimento di Chimica , Università degli studi di Firenze , Via della Lastruccia 13 , I-50019 , Sesto Fiorentino , Florence , Italy
| | - Annalise Di Marco
- Drug Discovery , IRBM Science Park , Via Pontina km 30,600 , Pomezia, Rome 00071 , Italy
| | - Maria Rosaria Battista
- Drug Discovery , IRBM Science Park , Via Pontina km 30,600 , Pomezia, Rome 00071 , Italy
| | - Vincenzo Summa
- Drug Discovery , IRBM Science Park , Via Pontina km 30,600 , Pomezia, Rome 00071 , Italy
| | - Roberta Costi
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
| | - Roberto Di Santo
- Istituto Pasteur-Fondazione Cenci Bolognetti , Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma , p. le Aldo Moro 5 , I-00185 Rome , Italy
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15
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Sutherland CS, Stone CM, Steinmann P, Tanner M, Tediosi F. Seeing beyond 2020: an economic evaluation of contemporary and emerging strategies for elimination of Trypanosoma brucei gambiense. LANCET GLOBAL HEALTH 2016; 5:e69-e79. [PMID: 27884709 DOI: 10.1016/s2214-109x(16)30237-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 08/29/2016] [Accepted: 08/30/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Trypanosoma brucei (T b) gambiense is targeted to reach elimination as a public health problem by 2020 and full elimination by 2030. To achieve these goals, stakeholders need to consider strategies to accelerate elimination. Hence, we aimed to model several options related to current and emerging methods for case detection, treatment, and vector control across settings to assess cost-effectiveness and the probability of elimination. METHODS Five intervention strategies were modelled over 30 years for low, moderate, and high transmission settings. Model parameters related to costs, efficacy, and transmission were based on available evidence and parameter estimation. Outcomes included disability-adjusted life-years (DALYs), costs, and long-term prevalence. Sensitivity analyses were done to calculate the uncertainty of the results. FINDINGS To reach elimination targets for 2020 across all settings, approaches combining case detection, treatment, and vector control would be most effective. Elimination in high and moderate transmission areas was probable and cost-effective when strategies included vector control and novel methods, with incremental cost-effectiveness ratios (ICERs) ranging from US$400 to $1500 per DALY averted. In low transmission areas, approaches including the newest interventions alone or in combination with tiny targets (vector control) were cost-effective, with ICERs of $200 or $1800 per DALY averted, respectively, but only strategies including vector control were likely to lead to elimination. Results of sensitivity analyses showed that allowing for biennial surveillance, reducing vector control maintenance costs, or variations of active surveillance coverage could also be cost-effective options for elimination, depending on the setting. INTERPRETATION Although various strategies might lead to elimination of T b gambiense, cost-effective approaches will include adoption of emerging technologies and, in some settings, increased surveillance or implementation of vector control. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
- C Simone Sutherland
- Swiss Tropical and Public Health Institute and Universität Basel, Basel, Switzerland
| | - Christopher M Stone
- Swiss Tropical and Public Health Institute and Universität Basel, Basel, Switzerland
| | - Peter Steinmann
- Swiss Tropical and Public Health Institute and Universität Basel, Basel, Switzerland
| | - Marcel Tanner
- Swiss Tropical and Public Health Institute and Universität Basel, Basel, Switzerland
| | - Fabrizio Tediosi
- Swiss Tropical and Public Health Institute and Universität Basel, Basel, Switzerland.
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16
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Pinsent A, Blake IM, Basáñez MG, Gambhir M. Mathematical Modelling of Trachoma Transmission, Control and Elimination. ADVANCES IN PARASITOLOGY 2016; 94:1-48. [PMID: 27756453 DOI: 10.1016/bs.apar.2016.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The World Health Organization has targeted the elimination of blinding trachoma by the year 2020. To this end, the Global Elimination of Blinding Trachoma (GET, 2020) alliance relies on a four-pronged approach, known as the SAFE strategy (S for trichiasis surgery; A for antibiotic treatment; F for facial cleanliness and E for environmental improvement). Well-constructed and parameterized mathematical models provide useful tools that can be used in policy making and forecasting in order to help to control trachoma and understand the feasibility of this large-scale elimination effort. As we approach this goal, the need to understand the transmission dynamics of infection within areas of different endemicities, to optimize available resources and to identify which strategies are the most cost-effective becomes more pressing. In this study, we conducted a review of the modelling literature for trachoma and identified 23 articles that included a mechanistic or statistical model of the transmission, dynamics and/or control of (ocular) Chlamydia trachomatis. Insights into the dynamics of trachoma transmission have been generated through both deterministic and stochastic models. A large body of the modelling work conducted to date has shown that, to varying degrees of effectiveness, antibiotic administration can reduce or interrupt trachoma transmission. However, very little analysis has been conducted to consider the effect of nonpharmaceutical interventions (and particularly the F and E components of the SAFE strategy) in helping to reduce transmission. Furthermore, very few of the models identified in the literature review included a structure that permitted tracking of the prevalence of active disease (in the absence of active infection) and the subsequent progression to disease sequelae (the morbidity associated with trachoma and ultimately the target of GET 2020 goals). This represents a critical gap in the current trachoma modelling literature, which makes it difficult to reliably link infection and disease. In addition, it hinders the application of modelling to assist the public health community in understanding whether trachoma programmes are on track to reach the GET goals by 2020. Another gap identified in this review was that of the 23 articles examined, only one considered the cost-effectiveness of the interventions implemented. We conclude that although good progress has been made towards the development of modelling frameworks for trachoma transmission, key components of disease sequelae representation and economic evaluation of interventions are currently missing from the available literature. We recommend that rapid advances in these areas should be urgently made to ensure that mathematical models for trachoma transmission can robustly guide elimination efforts and quantify progress towards GET 2020.
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Affiliation(s)
- A Pinsent
- Monash University, Melbourne, VIC, Australia
| | - I M Blake
- Imperial College London, London, United Kingdom
| | - M G Basáñez
- Imperial College London, London, United Kingdom
| | - M Gambhir
- Monash University, Melbourne, VIC, Australia
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17
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Bartsch SM, Hotez PJ, Asti L, Zapf KM, Bottazzi ME, Diemert DJ, Lee BY. The Global Economic and Health Burden of Human Hookworm Infection. PLoS Negl Trop Dis 2016; 10:e0004922. [PMID: 27607360 PMCID: PMC5015833 DOI: 10.1371/journal.pntd.0004922] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/23/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Even though human hookworm infection is highly endemic in many countries throughout the world, its global economic and health impact is not well known. Without a better understanding of hookworm's economic burden worldwide, it is difficult for decision makers such as funders, policy makers, disease control officials, and intervention manufacturers to determine how much time, energy, and resources to invest in hookworm control. METHODOLOGY/PRINCIPLE FINDINGS We developed a computational simulation model to estimate the economic and health burden of hookworm infection in every country, WHO region, and globally, in 2016 from the societal perspective. Globally, hookworm infection resulted in a total 2,126,280 DALYs using 2004 disability weight estimates and 4,087,803 DALYs using 2010 disability weight estimates (excluding cognitive impairment outcomes). Including cognitive impairment did not significantly increase DALYs worldwide. Total productivity losses varied with the probability of anemia and calculation method used, ranging from $7.5 billion to $138.9 billion annually using gross national income per capita as a proxy for annual wages and ranging from $2.5 billion to $43.9 billion using minimum wage as a proxy for annual wages. CONCLUSION Even though hookworm is classified as a neglected tropical disease, its economic and health burden exceeded published estimates for a number of diseases that have received comparatively more attention than hookworm such as rotavirus. Additionally, certain large countries that are transitioning to higher income countries such as Brazil and China, still face considerable hookworm burden.
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Affiliation(s)
- Sarah M. Bartsch
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Peter J. Hotez
- National School of Tropical Medicine, and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Sabin Vaccine Institute, Washington, D.C., United States of America
| | - Lindsey Asti
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Kristina M. Zapf
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Maria Elena Bottazzi
- National School of Tropical Medicine, and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Sabin Vaccine Institute, Washington, D.C., United States of America
| | - David J. Diemert
- Sabin Vaccine Institute, Washington, D.C., United States of America
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University Medical Center, Washington, D.C., United States of America
| | - Bruce Y. Lee
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
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Analysis of the population-level impact of co-administering ivermectin with albendazole or mebendazole for the control and elimination of Trichuris trichiura. Parasite Epidemiol Control 2016; 1:177-187. [PMID: 27430028 PMCID: PMC4946157 DOI: 10.1016/j.parepi.2016.02.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 11/25/2022] Open
Abstract
Introduction Soil-transmitted helminth (STH) infections are predominately controlled by providing children with preventive chemotherapy with either albendazole or mebendazole. However, neither has a high efficacy against Trichuris trichiura. This low efficacy limits the overall effectiveness of the current STH control programmes against T. trichiura. It has been demonstrated that co-administering ivermectin with albendazole or mebendazole significantly increases the efficacy of current treatments, which may increase the overall effectiveness of control programmes. Methods Using a STH transmission mathematical model, we evaluated the potential impact of co-administering ivermectin with albendazole or mebendazole to treat T. trichiura within a preventive chemotherapy programme targeting children (2–15 year olds). We evaluated the impact in terms of reduction in prevalent infections, mean worm burden, and prevalence of heavy infections. Results Although the current treatment strategy reduced T. trichiura worm burden and prevalence of heavy infections, due to their poor efficacy the long term impact of preventive chemotherapy for children was smaller compared to the other STH. Co-administering ivermectin increased the projected impact of the preventive chemotherapy programme in terms of all three of the explored metrics, practically in high transmission settings. Furthermore, ivermectin co-administration greatly increased the feasibility of and timeframe for breaking transmission. Conclusions Co-administering ivermectin notably increased the projected impact of preventive chemotherapy in high transmission settings and increased the feasibility for breaking transmission. This has important implications for control programmes, some of which may be shifting focus from morbidity control to interruption of transmission, and some of which may be logistically unable to provide preventive chemotherapy twice a year as recommended. However, the benefit of co-administering ivermectin is limited by the fact that 2–5 year olds are often ineligible to receive treatment. The impact of chemotherapy against Trichuris is smaller compared to what can be seen for the other soil-transmitted helminths. Co-administering ivermectin increases the projected impact of preventive chemotherapy. It also has the potential to interrupt transmission in some settings.
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Key Words
- ALB, albendazole
- Control
- ERRs, egg reduction rates
- Elimination
- IVM, ivermectin
- Ivermectin co-administration
- MBZ, mebendazole
- Mass drug administration
- Pre-SAC, preschool-aged
- R0, basic reproductive number
- SAC, school-aged children
- STH, soil-transmitted helminth
- Soil-transmitted helminth
- Trichuris trichiura
- WASH, water, sanitation and hygiene
- WHO, World Health Organisation
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Bartsch SM, Hotez PJ, Hertenstein DL, Diemert DJ, Zapf KM, Bottazzi ME, Bethony JM, Brown ST, Lee BY. Modeling the economic and epidemiologic impact of hookworm vaccine and mass drug administration (MDA) in Brazil, a high transmission setting. Vaccine 2016; 34:2197-206. [PMID: 27002501 DOI: 10.1016/j.vaccine.2016.03.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/03/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Although mass drug administration (MDA) has helped reduce morbidity attributed to soil-transmitted helminth infections in children, its limitations for hookworm infection have motivated the development of a human hookworm vaccine to both improve morbidity control and ultimately help block hookworm transmission leading to elimination. However, the potential economic and epidemiologic impact of a preventive vaccine has not been fully evaluated. METHODS We developed a dynamic compartment model coupled to a clinical and economics outcomes model representing both the human and hookworm populations in a high transmission region of Brazil. Experiments simulated different implementation scenarios of MDA and vaccination under varying circumstances. RESULTS Considering only intervention costs, both annual MDA and vaccination were highly cost-effective (ICERs ≤ $790/DALY averted) compared to no intervention, with vaccination resulting in lower incremental cost-effectiveness ratios (ICERs ≤ $444/DALY averted). From the societal perspective, vaccination was economically dominant (i.e., less costly and more effective) versus annual MDA in all tested scenarios, except when vaccination was less efficacious (20% efficacy, 5 year duration) and MDA coverage was 75%. Increasing the vaccine's duration of protection and efficacy, and including a booster injection in adulthood all increased the benefits of vaccination (i.e., resulted in lower hookworm prevalence, averted more disability-adjusted life years, and saved more costs). Assuming its target product profile, a pediatric hookworm vaccine drastically decreased hookworm prevalence in children to 14.6% after 20 years, compared to 57.2% with no intervention and 54.1% with MDA. The addition of a booster in adulthood further reduced the overall prevalence from 68.0% to 36.0% and nearly eliminated hookworm infection in children. CONCLUSION Using a human hookworm vaccine would be cost-effective and in many cases economically dominant, providing both health benefits and cost-savings. It could become a key technology in effecting control and elimination efforts for hookworm globally.
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Affiliation(s)
- Sarah M Bartsch
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Peter J Hotez
- National School of Tropical Medicine, and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113, Houston, TX 77030, USA; Sabin Vaccine Institute, 2000 Pennsylvania Avenue NW, Washington, DC 20006, USA
| | - Daniel L Hertenstein
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - David J Diemert
- Sabin Vaccine Institute, 2000 Pennsylvania Avenue NW, Washington, DC 20006, USA; Department of Microbiology, Immunology and Tropical Medicine, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Kristina M Zapf
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Maria Elena Bottazzi
- National School of Tropical Medicine, and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113, Houston, TX 77030, USA; Sabin Vaccine Institute, 2000 Pennsylvania Avenue NW, Washington, DC 20006, USA
| | - Jeffrey M Bethony
- Sabin Vaccine Institute, 2000 Pennsylvania Avenue NW, Washington, DC 20006, USA; Department of Microbiology, Immunology and Tropical Medicine, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Shawn T Brown
- Pittsburgh Supercomputing Center, Carnegie Mellon University, 300S Craig St, Pittsburgh, PA 15213, USA
| | - Bruce Y Lee
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA.
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Basáñez M, Walker M, Turner H, Coffeng L, de Vlas S, Stolk W. River Blindness: Mathematical Models for Control and Elimination. ADVANCES IN PARASITOLOGY 2016; 94:247-341. [PMID: 27756456 DOI: 10.1016/bs.apar.2016.08.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Human onchocerciasis (river blindness) is one of the few neglected tropical diseases (NTDs) whose control strategies have been informed by mathematical modelling. With the change in focus from elimination of the disease burden to elimination of Onchocerca volvulus, much remains to be done to refine, calibrate and validate existing models. Under the impetus of the NTD Modelling Consortium, the teams that developed EPIONCHO and ONCHOSIM have joined forces to compare and improve these frameworks to better assist ongoing elimination efforts. We review their current versions and describe how they are being used to address two key questions: (1) where can onchocerciasis be eliminated with current intervention strategies by 2020/2025? and (2) what alternative/complementary strategies could help to accelerate elimination where (1) cannot be achieved? The control and elimination of onchocerciasis from the African continent is at a crucial crossroad. The African Programme for Onchocerciasis Control closed at the end of 2015, and although a new platform for support and integration of NTD control has been launched, the disease will have to compete with a myriad of other national health priorities at a pivotal time in the road to elimination. However, never before had onchocerciasis control a better arsenal of intervention strategies as well as diagnostics. It is, therefore, timely to present two models of different geneses and modelling traditions as they come together to produce robust decision-support tools. We start by describing the structural and parametric assumptions of EPIONCHO and ONCHOSIM; we continue by summarizing the modelling of current treatment strategies with annual (or biannual) mass ivermectin distribution and introduce a number of alternative strategies, including other microfilaricidal therapies (such as moxidectin), macrofilaricidal (anti-wolbachial) treatments, focal vector control and the possibility of an onchocerciasis vaccine. We conclude by discussing challenges, opportunities and future directions.
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Nouvellet P, Cucunubá ZM, Gourbière S. Ecology, evolution and control of Chagas disease: a century of neglected modelling and a promising future. ADVANCES IN PARASITOLOGY 2015; 87:135-91. [PMID: 25765195 DOI: 10.1016/bs.apar.2014.12.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
More than 100 years after its formal description, Chagas disease remains a major public health concern in Latin America with a yearly burden of 430,000 Disability-Adjusted Life Years (DALYs). The aetiological agent, a protozoan named Trypanosoma cruzi, is mainly transmitted to mammalian hosts by triatomine vectors. Multiple species of mammals and triatomines can harbour and transmit the parasite, and the feeding range of triatomine species typically includes many noncompetent hosts. Furthermore, the transmission of the pathogen can occur via several routes including the typical vector's faeces, but also oral, congenital and blood transfusion routes. These ecological and epidemiological complexities of the disease have hindered many control initiatives. In such a context, mathematical models provide invaluable tools to explore and understand the dynamics of T. cruzi transmission, and to design, optimize and monitor the efficacy of control interventions. We intend here to provide the first review of the mathematical models of Chagas disease, focussing on how they have contributed to our understanding of (1) the population dynamics and control of triatomine vectors, and (2) the epidemiology of T. cruzi infections. We also aim at suggesting promising lines of modelling that could further improve our understanding of the ecology, evolution, and control of the disease.
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Affiliation(s)
- Pierre Nouvellet
- Medical Research Council Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Zulma M Cucunubá
- Grupo de Parasitología, Instituto Nacional de Salud, Colombia; Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Sébastien Gourbière
- Institut de Modélisation et d'Analyse en Géo-Environnements et Santé (IMAGES), Université de Perpignan Via Domitia, Perpignan, France
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