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Onifade AA, Rychtář J, Taylor D. A dynamic game of lymphatic filariasis prevention by voluntary use of insecticide treated nets. J Theor Biol 2024; 585:111796. [PMID: 38522665 DOI: 10.1016/j.jtbi.2024.111796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 03/15/2024] [Accepted: 03/16/2024] [Indexed: 03/26/2024]
Abstract
Lymphatic filariasis (LF) has been targeted for elimination as a public health concern by 2030 with a goal to keep the prevalence of LF infections under the 1% threshold. While mass drug administration (MDA) is a primary strategy recommended by WHO, the use of insecticide treated nets (ITN) plays a crucial role as an alternative strategy when MDA cannot be used. In this paper, we use imitation dynamics to incorporate human behavior and voluntary use of ITN into the compartmental epidemiological model of LF transmission. We find the equilibrium states of the dynamics and the ITN usage as it depends on epidemiological parameters and the cost of ITNs. We investigate the conditions under which the voluntary use of ITNs can keep the LF prevalence under the 1% threshold. We found that when the cost of using the ITNs is about 105 smaller than the perceived cost of LF, then the voluntary use of ITNs will eliminate LF as a public health concern. Furthermore, when the ITNs are given away for free, our model predicts that over 80% of the population will use them which would eliminate LF completely in regions where Anopheles are the primary vectors.
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Affiliation(s)
- Akindele Akano Onifade
- Department of Computer Science and Mathematics, Mountain Top University, Ibafo, Nigeria.
| | - Jan Rychtář
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA, United States of America.
| | - Dewey Taylor
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA, United States of America.
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Antony Oliver MC, Graham M, Gass KM, Medley GF, Clark J, Davis EL, Reimer LJ, King JD, Pouwels KB, Hollingsworth TD. Reducing the Antigen Prevalence Target Threshold for Stopping and Restarting Mass Drug Administration for Lymphatic Filariasis Elimination: A Model-Based Cost-effectiveness Simulation in Tanzania, India and Haiti. Clin Infect Dis 2024; 78:S160-S168. [PMID: 38662697 PMCID: PMC11045020 DOI: 10.1093/cid/ciae108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND The Global Programme to Eliminate Lymphatic Filariasis (GPELF) aims to reduce and maintain infection levels through mass drug administration (MDA), but there is evidence of ongoing transmission after MDA in areas where Culex mosquitoes are the main transmission vector, suggesting that a more stringent criterion is required for MDA decision making in these settings. METHODS We use a transmission model to investigate how a lower prevalence threshold (<1% antigenemia [Ag] prevalence compared with <2% Ag prevalence) for MDA decision making would affect the probability of local elimination, health outcomes, the number of MDA rounds, including restarts, and program costs associated with MDA and surveys across different scenarios. To determine the cost-effectiveness of switching to a lower threshold, we simulated 65% and 80% MDA coverage of the total population for different willingness to pay per disability-adjusted life-year averted for India ($446.07), Tanzania ($389.83), and Haiti ($219.84). RESULTS Our results suggest that with a lower Ag threshold, there is a small proportion of simulations where extra rounds are required to reach the target, but this also reduces the need to restart MDA later in the program. For 80% coverage, the lower threshold is cost-effective across all baseline prevalences for India, Tanzania, and Haiti. For 65% MDA coverage, the lower threshold is not cost-effective due to additional MDA rounds, although it increases the probability of local elimination. Valuing the benefits of elimination to align with the GPELF goals, we find that a willingness to pay per capita government expenditure of approximately $1000-$4000 for 1% increase in the probability of local elimination would be required to make a lower threshold cost-effective. CONCLUSIONS Lower Ag thresholds for stopping MDAs generally mean a higher probability of local elimination, reducing long-term costs and health impacts. However, they may also lead to an increased number of MDA rounds required to reach the lower threshold and, therefore, increased short-term costs. Collectively, our analyses highlight that lower target Ag thresholds have the potential to assist programs in achieving lymphatic filariasis goals.
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Affiliation(s)
- Mary Chriselda Antony Oliver
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Matthew Graham
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Katherine M Gass
- Neglected Tropical Diseases Support Centre, The Task Force for Global Health, Decatur, Georgia, USA
| | - Graham F Medley
- Centre for Mathematical Modelling of Infectious Disease and Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jessica Clark
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Emma L Davis
- Mathematics Institute and the Zeeman Institute for Systems Biology and Infectious Disease Epidemiological Research, University of Warwick, Coventry, United Kingdom
| | - Lisa J Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jonathan D King
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Koen B Pouwels
- Health Economics Research Centre, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - T Déirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
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Shaw C, McLure A, Graves PM, Lau CL, Glass K. Lymphatic filariasis endgame strategies: Using GEOFIL to model mass drug administration and targeted surveillance and treatment strategies in American Samoa. PLoS Negl Trop Dis 2023; 17:e0011347. [PMID: 37200375 DOI: 10.1371/journal.pntd.0011347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 05/31/2023] [Accepted: 04/29/2023] [Indexed: 05/20/2023] Open
Abstract
American Samoa underwent seven rounds of mass drug administration (MDA) for lymphatic filariasis (LF) from 2000-2006, but subsequent surveys found evidence of ongoing transmission. American Samoa has since undergone further rounds of MDA in 2018, 2019, and 2021; however, recent surveys indicate that transmission is still ongoing. GEOFIL, a spatially-explicit agent-based LF model, was used to compare the effectiveness of territory-wide triple-drug MDA (3D-MDA) with targeted surveillance and treatment strategies. Both approaches relied on treatment with ivermectin, diethylcarbamazine, and albendazole. We simulated three levels of whole population coverage for 3D-MDA: 65%, 73%, and 85%, while the targeted strategies relied on surveillance in schools, workplaces, and households, followed by targeted treatment. In the household-based strategies, we simulated 1-5 teams travelling village-to-village and offering antigen (Ag) testing to randomly selected households in each village. If an Ag-positive person was identified, treatment was offered to members of all households within 100m-1km of the positive case. All simulated interventions were finished by 2027 and their effectiveness was judged by their 'control probability'-the proportion of simulations in which microfilariae prevalence decreased between 2030 and 2035. Without future intervention, we predict Ag prevalence will rebound. With 3D-MDA, a 90% control probability required an estimated ≥ 4 further rounds with 65% coverage, ≥ 3 rounds with 73% coverage, or ≥ 2 rounds with 85% coverage. While household-based strategies were substantially more testing-intensive than 3D-MDA, they could offer comparable control probabilities with substantially fewer treatments; e.g. three teams aiming to test 50% of households and offering treatment to a 500m radius had approximately the same control probability as three rounds of 73% 3D-MDA, but used < 40% the number of treatments. School- and workplace-based interventions proved ineffective. Regardless of strategy, reducing Ag prevalence below the 1% target threshold recommended by the World Health Organization was a poor indicator of the interruption of LF transmission, highlighting the need to review blanket elimination targets.
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Affiliation(s)
- Callum Shaw
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
| | - Angus McLure
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
| | - Patricia M Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
| | - Colleen L Lau
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Kathryn Glass
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
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Rychtář J, Taylor D. A game-theoretic model of lymphatic filariasis prevention. PLoS Negl Trop Dis 2022; 16:e0010765. [PMID: 36137005 PMCID: PMC9498957 DOI: 10.1371/journal.pntd.0010765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 08/23/2022] [Indexed: 11/18/2022] Open
Abstract
Lymphatic filariasis (LF) is a mosquito-borne parasitic neglected tropical disease. In 2000, WHO launched the Global Programme to Eliminate Lymphatic Filariasis (GPELF) as a public health problem. In 2020, new goals for 2030 were set which includes a reduction to 0 of the total population requiring Mass Drug Administrations (MDA), a primary tool of GPELF. We develop a mathematical model to study what can happen at the end of MDA. We use a game-theoretic approach to assess the voluntary use of insect repellents in the prevention of the spread of LF through vector bites. Our results show that when individuals use what they perceive as optimal levels of protection, the LF incidence rates will become high. This is in striking difference to other vector-borne NTDs such as Chagas or zika. We conclude that the voluntary use of the protection alone will not be enough to keep LF eliminated as a public health problem and a more coordinated effort will be needed at the end of MDA.
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Affiliation(s)
- Jan Rychtář
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
| | - Dewey Taylor
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, United States of America
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Clark J, Stolk WA, Basáñez MG, Coffeng LE, Cucunubá ZM, Dixon MA, Dyson L, Hampson K, Marks M, Medley GF, Pollington TM, Prada JM, Rock KS, Salje H, Toor J, Hollingsworth TD. How modelling can help steer the course set by the World Health Organization 2021-2030 roadmap on neglected tropical diseases. Gates Open Res 2022; 5:112. [PMID: 35169682 PMCID: PMC8816801 DOI: 10.12688/gatesopenres.13327.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2022] [Indexed: 01/12/2023] Open
Abstract
The World Health Organization recently launched its 2021-2030 roadmap, Ending the Neglect to Attain the Sustainable Development Goals , an updated call to arms to end the suffering caused by neglected tropical diseases. Modelling and quantitative analyses played a significant role in forming these latest goals. In this collection, we discuss the insights, the resulting recommendations and identified challenges of public health modelling for 13 of the target diseases: Chagas disease, dengue, gambiense human African trypanosomiasis (gHAT), lymphatic filariasis (LF), onchocerciasis, rabies, scabies, schistosomiasis, soil-transmitted helminthiases (STH), Taenia solium taeniasis/ cysticercosis, trachoma, visceral leishmaniasis (VL) and yaws. This piece reflects the three cross-cutting themes identified across the collection, regarding the contribution that modelling can make to timelines, programme design, drug development and clinical trials.
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Affiliation(s)
- Jessica Clark
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Wilma A. Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, 3000 CA, The Netherlands
| | - María-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Luc E. Coffeng
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, 3000 CA, The Netherlands
| | - Zulma M. Cucunubá
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Matthew A. Dixon
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
- Schistosomiasis Control Initiative Foundation, London, SE11 5DP, UK
| | - Louise Dyson
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Katie Hampson
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Michael Marks
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Graham F. Medley
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London, WC1H 9SH, UK
| | - Timothy M. Pollington
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
| | - Joaquin M. Prada
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7AL, UK
| | - Kat S. Rock
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
| | - Henrik Salje
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - Jaspreet Toor
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - T. Déirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
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Clark J, Stolk WA, Basáñez MG, Coffeng LE, Cucunubá ZM, Dixon MA, Dyson L, Hampson K, Marks M, Medley GF, Pollington TM, Prada JM, Rock KS, Salje H, Toor J, Hollingsworth TD. How modelling can help steer the course set by the World Health Organization 2021-2030 roadmap on neglected tropical diseases. Gates Open Res 2021; 5:112. [PMID: 35169682 PMCID: PMC8816801 DOI: 10.12688/gatesopenres.13327.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2021] [Indexed: 01/12/2023] Open
Abstract
The World Health Organization recently launched its 2021-2030 roadmap, Ending the Neglect to Attain the Sustainable Development Goals , an updated call to arms to end the suffering caused by neglected tropical diseases. Modelling and quantitative analyses played a significant role in forming these latest goals. In this collection, we discuss the insights, the resulting recommendations and identified challenges of public health modelling for 13 of the target diseases: Chagas disease, dengue, gambiense human African trypanosomiasis (gHAT), lymphatic filariasis (LF), onchocerciasis, rabies, scabies, schistosomiasis, soil-transmitted helminthiases (STH), Taenia solium taeniasis/ cysticercosis, trachoma, visceral leishmaniasis (VL) and yaws. This piece reflects the three cross-cutting themes identified across the collection, regarding the contribution that modelling can make to timelines, programme design, drug development and clinical trials.
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Affiliation(s)
- Jessica Clark
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Wilma A. Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, 3000 CA, The Netherlands
| | - María-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Luc E. Coffeng
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, 3000 CA, The Netherlands
| | - Zulma M. Cucunubá
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Matthew A. Dixon
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
- Schistosomiasis Control Initiative Foundation, London, SE11 5DP, UK
| | - Louise Dyson
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Katie Hampson
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Michael Marks
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Graham F. Medley
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London, WC1H 9SH, UK
| | - Timothy M. Pollington
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
| | - Joaquin M. Prada
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7AL, UK
| | - Kat S. Rock
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
| | - Henrik Salje
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - Jaspreet Toor
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - T. Déirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
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Salonga PKN, Mendoza VMP, Mendoza RG, Belizario VY. A mathematical model of the dynamics of lymphatic filariasis in Caraga Region, the Philippines. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201965. [PMID: 34234950 PMCID: PMC8242838 DOI: 10.1098/rsos.201965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
Despite being one of the first countries to implement mass drug administration (MDA) for elimination of lymphatic filariasis (LF) in 2001 after a pilot study in 2000, the Philippines is yet to eliminate the disease as a public health problem with 6 out of the 46 endemic provinces still implementing MDA for LF as of 2018. In this work, we propose a mathematical model of the transmission dynamics of LF in the Philippines and a control strategy for its elimination using MDA. Sensitivity analysis using the Latin hypercube sampling and partial rank correlation coefficient methods suggests that the infected human population is most sensitive to the treatment parameters. Using the available LF data in Caraga Region from the Philippine Department of Health, we estimate the treatment rates r 1 and r 2 using the least-squares parameter estimation technique. Parameter bootstrapping showed small variability in the parameter estimates. Finally, we apply optimal control theory with the objective of minimizing the infected human population and the corresponding implementation cost of MDA, using the treatment coverage γ as the control parameter. Simulation results highlight the importance of maintaining a high MDA coverage per year to effectively minimize the infected population by the year 2030.
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Affiliation(s)
- Pamela Kim N. Salonga
- Institute of Mathematics, University of the Philippines Diliman, Quezon City, Philippines
- Natural Sciences Research Institute, University of the Philippines Diliman, Quezon City, Philippines
| | - Victoria May P. Mendoza
- Institute of Mathematics, University of the Philippines Diliman, Quezon City, Philippines
- Natural Sciences Research Institute, University of the Philippines Diliman, Quezon City, Philippines
| | - Renier G. Mendoza
- Institute of Mathematics, University of the Philippines Diliman, Quezon City, Philippines
- Natural Sciences Research Institute, University of the Philippines Diliman, Quezon City, Philippines
| | - Vicente Y. Belizario
- College of Public Health and Neglected Tropical Diseases Study Group, National Institutes of Health, University of the Philippines Manila, Philippines
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Turner HC. Health economic analyses of the Global Programme to Eliminate Lymphatic Filariasis. Int Health 2020; 13:S71-S74. [PMID: 33349885 PMCID: PMC7753169 DOI: 10.1093/inthealth/ihaa095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/30/2020] [Accepted: 11/19/2020] [Indexed: 11/14/2022] Open
Abstract
The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was established by the WHO in 2000. It aims to eliminate lymphatic filariasis as a public health problem. This paper summarises the key estimates of the cost-effectiveness and economic benefits related to the mass drug administration (MDA) provided by the GPELF. Several studies have investigated the cost-effectiveness of this MDA, estimating the cost per disability-adjusted life year (DALY) averted. These cost-effectiveness estimates have consistently classed the intervention as cost-effective and as favourable compared with other public health interventions conducted in low- and middle-income countries. Studies have also found that the MDA used for lymphatic filariasis control generates significant economic benefits. Although these studies are positive, there are still important gaps that warrant further health economic research (particularly, the evaluation of alternative interventions, further evaluation of morbidity management strategies and evaluation of interventions for settings coendemic with Loa loa). To conclude, health economic studies for a programme as large as the GPELF are subject to uncertainty. That said, the GPELF has consistently been estimated to be cost-effective and to generate notable economic benefits by a number of independent studies.
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Affiliation(s)
- Hugo C Turner
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary's Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK
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Xavier A, Oliveira H, Aguiar-Santos A, Barbosa Júnior W, da Silva E, Braga C, Bonfim C, Medeiros Z. Assessment of transmission in areas of uncertain endemicity for lymphatic filariasis in Brazil. PLoS Negl Trop Dis 2019; 13:e0007836. [PMID: 31765388 PMCID: PMC6917295 DOI: 10.1371/journal.pntd.0007836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 12/17/2019] [Accepted: 10/09/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The objective of the Global Program to Eliminate Lymphatic Filariasis (GPELF) is to phase out this endemic disease as a public health problem by 2020. Validation of elimination is obtained from the World Health Organization through evidence of non-transmission in countries that have already been subjected to mass drug administration (MDA) and in places adjoining these endemic areas. While three municipalities in Brazil have completed MDA, the epidemiological situation remains uncertain in nine adjoining municipalities. To determine the epidemiological status, this study was to perform a review of the literature and a school-based survey to describe the past and recent endemicity of lymphatic filariasis (LF) theses nine municipalities in Brazil. METHODOLOGY/PRINCIPLE FINDINGS For review of the literature, both formal and informal literature sources were accessed since the first reports of filariasis in the Metropolitan Region of Recife, Brazil. We conducted a school-based survey in 2016 using immunochromatographic card tests (ICTs) among schoolchildren aged 6-10 years living in nine municipalities contiguous with the endemic areas in which MDA was conducted. Our review of the literature identified eight studies involving surveys demonstrating that microfilariae had been circulating in eight of the municipalities since 1967, with a low prevalence of microfilaremia, isolated autochthonous cases, and treatment of individual cases. The school-based survey included 17,222 children in 185 urban schools in the nine areas of Brazil with uncertain endemicity. One child affected by allochthonous transmission was antigen positive based on ICT and lived in a municipality adjacent to Recife; this child's family came from Recife, but no other case was diagnosed within the family. CONCLUSIONS/SIGNIFICANCE The study results suggest that there is no transmission of LF in the municipalities investigated. However, these areas have population migration and socioenvironmental conditions favorable to mosquito breeding grounds; therefore, surveillance is strongly recommended in these areas.
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Affiliation(s)
- Amanda Xavier
- Programa de Pós-graduação em Ciências da Saúde, Universidade de Pernambuco, Recife, Brazil
- * E-mail:
| | - Heloize Oliveira
- Programa de Pós-graduação em Ciências da Saúde, Universidade de Pernambuco, Recife, Brazil
- Agência Pernambucana de Vigilância Sanitária, Secretaria de Saúde do Estado de Pernambuco, Recife, Brazil
| | - Ana Aguiar-Santos
- Departamento de Parasitologia, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Brazil
| | - Walter Barbosa Júnior
- Departamento de Parasitologia, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Brazil
| | - Ellyda da Silva
- Departamento de Parasitologia, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Brazil
| | - Cynthia Braga
- Departamento de Parasitologia, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Brazil
| | - Cristine Bonfim
- Diretoria de Pesquisas Sociais, Fundação Joaquim Nabuco, Ministério da Educação, Recife, Brazil
- Programa de Pós-graduação em Saúde Coletiva, Universidade Federal de Pernambuco, Recife, Brazil
| | - Zulma Medeiros
- Programa de Pós-graduação em Ciências da Saúde, Universidade de Pernambuco, Recife, Brazil
- Departamento de Parasitologia, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Brazil
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Nandha B, Meenakshy V, Abdul Khader N, Vijayakumar KN, Jambulingam P. Bridging the gap in outreach and compliance with mass drug administration for lymphatic filariasis elimination in an endemic district in Kerala, India: an intervention research approach. HEALTH EDUCATION RESEARCH 2019; 34:300-309. [PMID: 30805648 DOI: 10.1093/her/cyz005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
Lymphatic filariasis (LF), a neglected tropical disease is targeted for elimination globally by 2020. National Health Policy of India set the goal by 2017 and annual single-dose mass drug administration (MDA) with anti-filarial drugs is in operation in endemic districts since 2004. Performance and effectiveness of MDA was diverse across the nation and prevalence of infection continues above threshold level in 50% of endemic districts which requires alternative strategies. National programme aims at achieving >65% consumption for transmission control. Post 10 rounds of MDA in an endemic district of Kerala state, a three-arm study identified determinants in gap in outreach and consumption, based on which context-dependent intervention using social group work and networking (SGWN) was implemented and impact assessed. A spill over effect with overall increase in coverage and consumption rates irrespective of arms apparently is due to inclusive improvement in MDA programme whereas, significant relative improvement in intervention arm reflects effectiveness of SGWN strategy. Though reduction in microfilaria prevalence in all arms was observed, it was significant between intervention and comparison arm. This study highlights need for context-dependent communication strategy to improve MDA for accelerating LF elimination by the targeted 2020.
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Affiliation(s)
- B Nandha
- Vector Control Research Centre, (Indian Council of Medical Research), Medical Complex, Indira Nagar, Pondicherry, India
| | - V Meenakshy
- Office of the Directorate of Health Services, Tiruvananthapuram, Kerala, India
| | | | - K N Vijayakumar
- Vector Control Research Centre, (Indian Council of Medical Research), Medical Complex, Indira Nagar, Pondicherry, India
| | - P Jambulingam
- Vector Control Research Centre, (Indian Council of Medical Research), Medical Complex, Indira Nagar, Pondicherry, India
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11
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Sutherland CS, Tediosi F. Is the elimination of 'sleeping sickness' affordable? Who will pay the price? Assessing the financial burden for the elimination of human African trypanosomiasis Trypanosoma brucei gambiense in sub-Saharan Africa. BMJ Glob Health 2019; 4:e001173. [PMID: 31139437 PMCID: PMC6509604 DOI: 10.1136/bmjgh-2018-001173] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 03/07/2019] [Accepted: 03/09/2019] [Indexed: 12/11/2022] Open
Abstract
Introduction Programme to eliminate neglected tropical diseases (NTDs) have gained global recognition, and may allow for improvements to universal health coverage and poverty alleviation. It is hoped that elimination of human African trypanosomiasis (HAT) Trypanosoma brucei gambiense (Tbg) would assist in this goal, but the financial costs are still unknown. The objective of this analysis was to forecast the financial burden of direct costs of HAT Tbg to funders and society. Methods In order to estimate the total costs to health services and individuals: (1) potential elimination programmes were defined; (2) the direct costs of programmes were calculated; (3) the per case out-of-pocket payments (OOPs) by programme and financial risk protection indicators were estimated. The total estimated costs for control and elimination programme were reported up till 2020 in international dollars. The mean results for both direct programme costs and OOPs were calculated and reported along with 95% CIs. Results Across sub-Saharan Africa, HAT Tbg maintaining ‘Control’ would lead to a decline in cases and cost US$630.6 million. In comparison, the cost of ‘Elimination’ programme ranged from US$410.9 million to US$1.2 billion. Maintaining ‘Control’ would continue to cause impoverishment and financial hardship to households; while all ‘Elimination’ programme would lead to significant reductions in poverty. Conclusion Overall, the total costs of either control or elimination programme would be near US$1 billion in the next decade. However, only elimination programme will reduce the number of cases and improve financial risk protection for households who are impacted by HAT Tbg.
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Affiliation(s)
- C Simone Sutherland
- Institute of Pharmaceutical Medicine, Universitat Basel Medizinische Fakultat, Basel, Switzerland.,Department of Epidemiology and Public Health (EPH), Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Fabrizio Tediosi
- Department of Epidemiology and Public Health (EPH), Swiss Tropical and Public Health Institute, Basel, Switzerland.,Department of Public Health, University of Basel, Basel, Switzerland
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12
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Korhonen PK, Hall RS, Young ND, Gasser RB. Common workflow language (CWL)-based software pipeline for de novo genome assembly from long- and short-read data. Gigascience 2019; 8:giz014. [PMID: 30821816 PMCID: PMC6451199 DOI: 10.1093/gigascience/giz014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/03/2018] [Accepted: 01/25/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Here, we created an automated pipeline for the de novoassembly of genomes from Pacific Biosciences long-read and Illumina short-read data using common workflow language (CWL). To evaluate the performance of this pipeline, we assembled the nuclear genomes of the eukaryotes Caenorhabditis elegans (∼100 Mb), Drosophila melanogaster (∼138 Mb), and Plasmodium falciparum (∼23 Mb) directly from publicly accessible nucleotide sequence datasets and assessed the quality of the assemblies against curated reference genomes. FINDINGS We showed a dependency of the accuracy of assembly on sequencing technology and GC content and repeatedly achieved assemblies that meet the high standards set by the National Human Genome Research Institute, being applicable to gene prediction and subsequent genomic analyses. CONCLUSIONS This CWL pipeline overcomes current challenges of achieving repeatability and reproducibility of assembly results and offers a platform for the re-use of the workflow and the integration of diverse datasets. This workflow is publicly available via GitHub (https://github.com/vetscience/Assemblosis) and is currently applicable to the assembly of haploid and diploid genomes of eukaryotes.
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Affiliation(s)
- Pasi K Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Ross S Hall
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
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13
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Gedge LM, Bettis AA, Bradley MH, Hollingsworth TD, Turner HC. Economic evaluations of lymphatic filariasis interventions: a systematic review and research needs. Parasit Vectors 2018; 11:75. [PMID: 29391042 PMCID: PMC5793442 DOI: 10.1186/s13071-018-2616-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 01/02/2018] [Indexed: 01/13/2023] Open
Abstract
In 2000, the World Health Organization established the Global Programme to Eliminate Lymphatic Filariasis (GPELF), with the goal of eliminating the disease as a public health problem by 2020. Since the start of the programme, a cumulative total of 6.2 billion treatments have been delivered to affected populations - with more than 556 million people treated in 2015 alone. In this paper, we perform a rigorous systematic review of the economic evaluations of lymphatic filariasis interventions have been conducted. We demonstrate that the standard interventions to control lymphatic filariasis are consistently found to be highly cost-effective. This finding has important implications for advocacy groups and potential funders. However, there are several important inconsistencies and research gaps that need to be addressed as we move forward towards the 2020 elimination goals. One of the most important identified research gaps was a lack of evaluation of new interventions specifically targeting areas co-endemic with onchocerciasis and Loa loa - which could become a major barrier to achieving elimination.
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Affiliation(s)
- Lukyn M. Gedge
- School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG UK
| | - Alison A. Bettis
- London Centre for Neglected Tropical Disease Research, London, UK
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG UK
| | | | - T. Déirdre Hollingsworth
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL UK
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL UK
- Big Data Institute, University of Oxford, Oxford, OX3 7LF UK
| | - Hugo C. Turner
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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14
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Turner HC, Bettis AA, Chu BK, McFarland DA, Hooper PJ, Mante SD, Fitzpatrick C, Bradley MH. Investment Success in Public Health: An Analysis of the Cost-Effectiveness and Cost-Benefit of the Global Programme to Eliminate Lymphatic Filariasis. Clin Infect Dis 2017; 64:728-735. [PMID: 27956460 PMCID: PMC5404931 DOI: 10.1093/cid/ciw835] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/30/2017] [Indexed: 11/25/2022] Open
Abstract
Background. It has been estimated that $154 million per year will be required during 2015–2020 to continue the Global Programme to Eliminate Lymphatic Filariasis (GPELF). In light of this, it is important to understand the program’s current value. Here, we evaluate the cost-effectiveness and cost-benefit of the preventive chemotherapy that was provided under the GPELF between 2000 and 2014. In addition, we also investigate the potential cost-effectiveness of hydrocele surgery. Methods. Our economic evaluation of preventive chemotherapy was based on previously published health and economic impact estimates (between 2000 and 2014). The delivery costs of treatment were estimated using a model developed by the World Health Organization. We also developed a model to investigate the number of disability-adjusted life years (DALYs) averted by a hydrocelectomy and identified the cost threshold under which it would be considered cost-effective. Results. The projected cost-effectiveness and cost-benefit of preventive chemotherapy were very promising, and this was robust over a wide range of costs and assumptions. When the economic value of the donated drugs was not included, the GPELF would be classed as highly cost-effective. We projected that a typical hydrocelectomy would be classed as highly cost-effective if the surgery cost less than $66 and cost-effective if less than $398 (based on the World Bank’s cost-effectiveness thresholds for low income countries). Conclusions. Both the preventive chemotherapy and hydrocele surgeries provided under the GPELF are incredibly cost-effective and offer a very good investment in public health.
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Affiliation(s)
- Hugo C Turner
- London Centre for Neglected Tropical Disease Research, London, UK.,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, UK.,Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Alison A Bettis
- London Centre for Neglected Tropical Disease Research, London, UK.,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, UK
| | - Brian K Chu
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, Atlanta, GA, USA
| | | | - Pamela J Hooper
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, Atlanta, GA, USA
| | - Sunny D Mante
- Urology Unit, 37 Military Hospital, Korle-Bu, Accra, Ghana
| | - Christopher Fitzpatrick
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
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15
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Xu Z, Glass K, Lau CL, Geard N, Graves P, Clements A. A Synthetic Population for Modelling the Dynamics of Infectious Disease Transmission in American Samoa. Sci Rep 2017; 7:16725. [PMID: 29196679 PMCID: PMC5711879 DOI: 10.1038/s41598-017-17093-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 11/20/2017] [Indexed: 11/09/2022] Open
Abstract
Agent-based modelling is a useful approach for capturing heterogeneity in disease transmission. In this study, a synthetic population was developed for American Samoa using an iterative approach based on population census, questionnaire survey and land use data. The population will be used as the basis for a new agent-based model, intended specifically to fill the knowledge gaps about lymphatic filariasis transmission and elimination, but also to be readily adaptable to model other infectious diseases. The synthetic population was characterized by the statistically realistic population and household structure, and high-resolution geographic locations of households. The population was simulated over 40 years from 2010 to 2050. The simulated population was compared to estimates and projections of the U.S. Census Bureau. The results showed the total population would continuously decrease due to the observed large number of emigrants. Population ageing was observed, which was consistent with the latest two population censuses and the Bureau's projections. The sex ratios by age groups were analysed and indicated an increase in the proportion of males in age groups 0-14 and 15-64. The household size followed a Gaussian distribution with an average size of around 5.0 throughout the simulation, slightly less than the initial average size 5.6.
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Affiliation(s)
- Zhijing Xu
- Research School of Population Health, Australian National University, Canberra, Australia.
| | - Kathryn Glass
- Research School of Population Health, Australian National University, Canberra, Australia
| | - Colleen L Lau
- Research School of Population Health, Australian National University, Canberra, Australia
| | - Nicholas Geard
- School of Computing and Information Systems, University of Melbourne, Melbourne, Australia.,Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Patricia Graves
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Archie Clements
- Research School of Population Health, Australian National University, Canberra, Australia
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Steinmann P, Reed SG, Mirza F, Hollingsworth TD, Richardus JH. Innovative tools and approaches to end the transmission of Mycobacterium leprae. THE LANCET. INFECTIOUS DISEASES 2017; 17:e298-e305. [DOI: 10.1016/s1473-3099(17)30314-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 03/26/2017] [Accepted: 04/06/2017] [Indexed: 12/23/2022]
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17
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Global elimination of lymphatic filariasis. THE LANCET. INFECTIOUS DISEASES 2017; 17:358-359. [DOI: 10.1016/s1473-3099(16)30544-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 11/02/2016] [Indexed: 11/17/2022]
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18
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Lessons Learned From Developing an Eradication Investment Case for Lymphatic Filariasis. ADVANCES IN PARASITOLOGY 2016; 94:393-417. [PMID: 27756458 DOI: 10.1016/bs.apar.2016.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the last few years, the concepts of disease elimination and eradication have again gained consideration from the global health community, with Guinea worm disease (dracunculiasis) on track to become the first parasitic disease to be eradicated. Given the many complex and interlinking issues involved in committing to a disease eradication initiative, such commitments must be based on a solid assessment of a broad range of factors. In this chapter, we discuss the value and implications of undertaking a systematic and fact-based analysis of the overall situation prior to embarking on an elimination or eradication programme. As an example, we draw upon insights gained from a series of lymphatic filariasis (LF) studies from our research group that adopted an eradication investment case (EIC) framework. The justification for EICs, and related epidemiological, geospatial and other mathematical/operational research modelling, stems from the necessity for proper planning prior to committing to disease eradication. Across all considerations for LF eradication, including: time, treatments, level of investments necessary, health impact, cost-effectiveness, and broader economic benefits, scaling-up mass drug administration coverage to all endemic communities immediately provided the most favourable results. The coherent and consistent pursuit of eradication goals, operationally tailored to a given socioecological system and based on integrated measures of available tools will lead relatively rapidly to elimination in many parts of endemic areas and provide the cornerstone towards eradication.
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Jambulingam P, Subramanian S, de Vlas SJ, Vinubala C, Stolk WA. Mathematical modelling of lymphatic filariasis elimination programmes in India: required duration of mass drug administration and post-treatment level of infection indicators. Parasit Vectors 2016; 9:501. [PMID: 27624157 PMCID: PMC5022201 DOI: 10.1186/s13071-016-1768-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 08/22/2016] [Indexed: 12/03/2022] Open
Abstract
Background India has made great progress towards the elimination of lymphatic filariasis. By 2015, most endemic districts had completed at least five annual rounds of mass drug administration (MDA). The next challenge is to determine when MDA can be stopped. We performed a simulation study with the individual-based model LYMFASIM to help clarify this. Methods We used a model-variant for Indian settings. We considered different hypotheses on detectability of antigenaemia (Ag) in relation to underlying adult worm burden, choosing the most likely hypothesis by comparing the model predicted association between community-level microfilaraemia (Mf) and antigenaemia (Ag) prevalence levels to observed data (collated from literature). Next, we estimated how long MDA must be continued in order to achieve elimination in different transmission settings and what Mf and Ag prevalence may still remain 1 year after the last required MDA round. The robustness of key-outcomes was assessed in a sensitivity analysis. Results Our model matched observed data qualitatively well when we assumed an Ag detection rate of 50 % for single worm infections, which increases with the number of adult worms (modelled by relating detection to the presence of female worms). The required duration of annual MDA increased with higher baseline endemicity and lower coverage (varying between 2 and 12 rounds), while the remaining residual infection 1 year after the last required treatment declined with transmission intensity. For low and high transmission settings, the median residual infection levels were 1.0 % and 0.4 % (Mf prevalence in the 5+ population), and 3.5 % and 2.0 % (Ag prevalence in 6–7 year-old children). Conclusion To achieve elimination in high transmission settings, MDA must be continued longer and infection levels must be reduced to lower levels than in low-endemic communities. Although our simulations were for Indian settings, qualitatively similar patterns are also expected in other areas. This should be taken into account in decision algorithms to define whether MDA can be interrupted. Transmission assessment surveys should ideally be targeted to communities with the highest pre-control transmission levels, to minimize the risk of programme failure. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1768-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Purushothaman Jambulingam
- Vector Control Research Centre (Indian Council of Medical Research), Indira Nagar, Puducherry, 605006, India
| | - Swaminathan Subramanian
- Vector Control Research Centre (Indian Council of Medical Research), Indira Nagar, Puducherry, 605006, India.
| | - S J de Vlas
- Department of Public Health, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Chellasamy Vinubala
- Vector Control Research Centre (Indian Council of Medical Research), Indira Nagar, Puducherry, 605006, India
| | - W A Stolk
- Department of Public Health, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
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