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Measles on the Edge: Coastal Heterogeneities and Infection Dynamics

Mathematical models can help elucidate the spatio-temporal dynamics of epidemics as well as the impact of control measures. The gravity model for directly transmitted diseases is currently one of the most parsimonious models for spatial epidemic spread. This model uses distance-weighted, population...

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Detalles Bibliográficos
Autores principales: Bharti, Nita, Xia, Yingcun, Bjornstad, Ottar N., Grenfell, Bryan T.
Formato: Texto
Lenguaje:English
Publicado: Public Library of Science 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2275791/
https://www.ncbi.nlm.nih.gov/pubmed/18398467
http://dx.doi.org/10.1371/journal.pone.0001941
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author Bharti, Nita
Xia, Yingcun
Bjornstad, Ottar N.
Grenfell, Bryan T.
author_facet Bharti, Nita
Xia, Yingcun
Bjornstad, Ottar N.
Grenfell, Bryan T.
author_sort Bharti, Nita
collection PubMed
description Mathematical models can help elucidate the spatio-temporal dynamics of epidemics as well as the impact of control measures. The gravity model for directly transmitted diseases is currently one of the most parsimonious models for spatial epidemic spread. This model uses distance-weighted, population size-dependent coupling to estimate host movement and disease incidence in metapopulations. The model captures overall measles dynamics in terms of underlying human movement in pre-vaccination England and Wales (previously established). In spatial models, edges often present a special challenge. Therefore, to test the model's robustness, we analyzed gravity model incidence predictions for coastal cities in England and Wales. Results show that, although predictions are accurate for inland towns, they significantly underestimate coastal persistence. We examine incidence, outbreak seasonality, and public transportation records, to show that the model's inaccuracies stem from an underestimation of total contacts per individual along the coast. We rescue this predicted ‘edge effect’ by increasing coastal contacts to approximate the number of per capita inland contacts. These results illustrate the impact of ‘edge effects’ on epidemic metapopulations in general and illustrate directions for the refinement of spatiotemporal epidemic models.
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spelling pubmed-22757912008-04-09 Measles on the Edge: Coastal Heterogeneities and Infection Dynamics Bharti, Nita Xia, Yingcun Bjornstad, Ottar N. Grenfell, Bryan T. PLoS One Research Article Mathematical models can help elucidate the spatio-temporal dynamics of epidemics as well as the impact of control measures. The gravity model for directly transmitted diseases is currently one of the most parsimonious models for spatial epidemic spread. This model uses distance-weighted, population size-dependent coupling to estimate host movement and disease incidence in metapopulations. The model captures overall measles dynamics in terms of underlying human movement in pre-vaccination England and Wales (previously established). In spatial models, edges often present a special challenge. Therefore, to test the model's robustness, we analyzed gravity model incidence predictions for coastal cities in England and Wales. Results show that, although predictions are accurate for inland towns, they significantly underestimate coastal persistence. We examine incidence, outbreak seasonality, and public transportation records, to show that the model's inaccuracies stem from an underestimation of total contacts per individual along the coast. We rescue this predicted ‘edge effect’ by increasing coastal contacts to approximate the number of per capita inland contacts. These results illustrate the impact of ‘edge effects’ on epidemic metapopulations in general and illustrate directions for the refinement of spatiotemporal epidemic models. Public Library of Science 2008-04-09 /pmc/articles/PMC2275791/ /pubmed/18398467 http://dx.doi.org/10.1371/journal.pone.0001941 Text en Bharti et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Bharti, Nita
Xia, Yingcun
Bjornstad, Ottar N.
Grenfell, Bryan T.
Measles on the Edge: Coastal Heterogeneities and Infection Dynamics
title Measles on the Edge: Coastal Heterogeneities and Infection Dynamics
title_full Measles on the Edge: Coastal Heterogeneities and Infection Dynamics
title_fullStr Measles on the Edge: Coastal Heterogeneities and Infection Dynamics
title_full_unstemmed Measles on the Edge: Coastal Heterogeneities and Infection Dynamics
title_short Measles on the Edge: Coastal Heterogeneities and Infection Dynamics
title_sort measles on the edge: coastal heterogeneities and infection dynamics
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2275791/
https://www.ncbi.nlm.nih.gov/pubmed/18398467
http://dx.doi.org/10.1371/journal.pone.0001941
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