Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.

Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the mi...

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Main Authors: Qifang Bi, Andrew S Azman, Syed Moinuddin Satter, Azharul Islam Khan, Dilruba Ahmed, Altaf Ahmed Riaj, Emily S Gurley, Justin Lessler
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2016-02-01
Series:PLoS Neglected Tropical Diseases
Online Access:http://europepmc.org/articles/PMC4750854?pdf=render
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spelling doaj-1c5aafbf7a49480b823e4802e1d8e4832020-11-25T01:21:39ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352016-02-01102e000440010.1371/journal.pntd.0004400Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.Qifang BiAndrew S AzmanSyed Moinuddin SatterAzharul Islam KhanDilruba AhmedAltaf Ahmed RiajEmily S GurleyJustin LesslerClose interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets) near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs) to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98), type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00), and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00) exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a cholera endemic population suggests a possible role for highly targeted interventions. Studies with cluster designs in areas with strong spatial clustering of exposures should increase sample size to account for the correlation of these exposures.http://europepmc.org/articles/PMC4750854?pdf=render
collection DOAJ
language English
format Article
sources DOAJ
author Qifang Bi
Andrew S Azman
Syed Moinuddin Satter
Azharul Islam Khan
Dilruba Ahmed
Altaf Ahmed Riaj
Emily S Gurley
Justin Lessler
spellingShingle Qifang Bi
Andrew S Azman
Syed Moinuddin Satter
Azharul Islam Khan
Dilruba Ahmed
Altaf Ahmed Riaj
Emily S Gurley
Justin Lessler
Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.
PLoS Neglected Tropical Diseases
author_facet Qifang Bi
Andrew S Azman
Syed Moinuddin Satter
Azharul Islam Khan
Dilruba Ahmed
Altaf Ahmed Riaj
Emily S Gurley
Justin Lessler
author_sort Qifang Bi
title Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.
title_short Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.
title_full Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.
title_fullStr Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.
title_full_unstemmed Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.
title_sort micro-scale spatial clustering of cholera risk factors in urban bangladesh.
publisher Public Library of Science (PLoS)
series PLoS Neglected Tropical Diseases
issn 1935-2727
1935-2735
publishDate 2016-02-01
description Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets) near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs) to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98), type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00), and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00) exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a cholera endemic population suggests a possible role for highly targeted interventions. Studies with cluster designs in areas with strong spatial clustering of exposures should increase sample size to account for the correlation of these exposures.
url http://europepmc.org/articles/PMC4750854?pdf=render
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