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Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study
BACKGROUND: Reactive case detection could be a powerful tool in malaria elimination, as it selectively targets transmission pockets. However, field operations have yet to demonstrate under which conditions, if any, reactive case detection is best poised to push a region to elimination. This study us...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5469005/ https://www.ncbi.nlm.nih.gov/pubmed/28606143 http://dx.doi.org/10.1186/s12936-017-1903-z |
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author | Gerardin, Jaline Bever, Caitlin A. Bridenbecker, Daniel Hamainza, Busiku Silumbe, Kafula Miller, John M. Eisele, Thomas P. Eckhoff, Philip A. Wenger, Edward A. |
author_facet | Gerardin, Jaline Bever, Caitlin A. Bridenbecker, Daniel Hamainza, Busiku Silumbe, Kafula Miller, John M. Eisele, Thomas P. Eckhoff, Philip A. Wenger, Edward A. |
author_sort | Gerardin, Jaline |
collection | PubMed |
description | BACKGROUND: Reactive case detection could be a powerful tool in malaria elimination, as it selectively targets transmission pockets. However, field operations have yet to demonstrate under which conditions, if any, reactive case detection is best poised to push a region to elimination. This study uses mathematical modelling to assess how baseline transmission intensity and local interconnectedness affect the impact of reactive activities in the context of other possible intervention packages. METHODS: Communities in Southern Province, Zambia, where elimination operations are currently underway, were used as representatives of three archetypes of malaria transmission: low-transmission, high household density; high-transmission, low household density; and high-transmission, high household density. Transmission at the spatially-connected household level was simulated with a dynamical model of malaria transmission, and local variation in vectorial capacity and intervention coverage were parameterized according to data collected from the area. Various potential intervention packages were imposed on each of the archetypical settings and the resulting likelihoods of elimination by the end of 2020 were compared. RESULTS: Simulations predict that success of elimination campaigns in both low- and high-transmission areas is strongly dependent on stemming the flow of imported infections, underscoring the need for regional-scale strategies capable of reducing transmission concurrently across many connected areas. In historically low-transmission areas, treatment of clinical malaria should form the cornerstone of elimination operations, as most malaria infections in these areas are symptomatic and onward transmission would be mitigated through health system strengthening; reactive case detection has minimal impact in these settings. In historically high-transmission areas, vector control and case management are crucial for limiting outbreak size, and the asymptomatic reservoir must be addressed through reactive case detection or mass drug campaigns. CONCLUSIONS: Reactive case detection is recommended only for settings where transmission has recently been reduced rather than all low-transmission settings. This is demonstrated in a modelling framework with strong out-of-sample accuracy across a range of transmission settings while including methodologies for understanding the most resource-effective allocations of health workers. This approach generalizes to providing a platform for planning rational scale-up of health systems based on locally-optimized impact according to simplified stratification. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12936-017-1903-z) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-5469005 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-54690052017-06-14 Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study Gerardin, Jaline Bever, Caitlin A. Bridenbecker, Daniel Hamainza, Busiku Silumbe, Kafula Miller, John M. Eisele, Thomas P. Eckhoff, Philip A. Wenger, Edward A. Malar J Research BACKGROUND: Reactive case detection could be a powerful tool in malaria elimination, as it selectively targets transmission pockets. However, field operations have yet to demonstrate under which conditions, if any, reactive case detection is best poised to push a region to elimination. This study uses mathematical modelling to assess how baseline transmission intensity and local interconnectedness affect the impact of reactive activities in the context of other possible intervention packages. METHODS: Communities in Southern Province, Zambia, where elimination operations are currently underway, were used as representatives of three archetypes of malaria transmission: low-transmission, high household density; high-transmission, low household density; and high-transmission, high household density. Transmission at the spatially-connected household level was simulated with a dynamical model of malaria transmission, and local variation in vectorial capacity and intervention coverage were parameterized according to data collected from the area. Various potential intervention packages were imposed on each of the archetypical settings and the resulting likelihoods of elimination by the end of 2020 were compared. RESULTS: Simulations predict that success of elimination campaigns in both low- and high-transmission areas is strongly dependent on stemming the flow of imported infections, underscoring the need for regional-scale strategies capable of reducing transmission concurrently across many connected areas. In historically low-transmission areas, treatment of clinical malaria should form the cornerstone of elimination operations, as most malaria infections in these areas are symptomatic and onward transmission would be mitigated through health system strengthening; reactive case detection has minimal impact in these settings. In historically high-transmission areas, vector control and case management are crucial for limiting outbreak size, and the asymptomatic reservoir must be addressed through reactive case detection or mass drug campaigns. CONCLUSIONS: Reactive case detection is recommended only for settings where transmission has recently been reduced rather than all low-transmission settings. This is demonstrated in a modelling framework with strong out-of-sample accuracy across a range of transmission settings while including methodologies for understanding the most resource-effective allocations of health workers. This approach generalizes to providing a platform for planning rational scale-up of health systems based on locally-optimized impact according to simplified stratification. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12936-017-1903-z) contains supplementary material, which is available to authorized users. BioMed Central 2017-06-12 /pmc/articles/PMC5469005/ /pubmed/28606143 http://dx.doi.org/10.1186/s12936-017-1903-z Text en © The Author(s) 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Gerardin, Jaline Bever, Caitlin A. Bridenbecker, Daniel Hamainza, Busiku Silumbe, Kafula Miller, John M. Eisele, Thomas P. Eckhoff, Philip A. Wenger, Edward A. Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study |
title | Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study |
title_full | Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study |
title_fullStr | Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study |
title_full_unstemmed | Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study |
title_short | Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study |
title_sort | effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5469005/ https://www.ncbi.nlm.nih.gov/pubmed/28606143 http://dx.doi.org/10.1186/s12936-017-1903-z |
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