{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T04:33:57Z","timestamp":1787891637395,"version":"build-2784847793"},"reference-count":22,"publisher":"BMJ","issue":"9","license":[{"start":{"date-parts":[[2022,9,21]],"date-time":"2022-09-21T00:00:00Z","timestamp":1663718400000},"content-version":"unspecified","delay-in-days":20,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000865","name":"Bill and Melinda Gates Foundation","doi-asserted-by":"publisher","award":["INV-025386"],"award-info":[{"award-number":["INV-025386"]}],"id":[{"id":"10.13039\/100000865","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2022,8,25]]},"published-print":{"date-parts":[[2022,9]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To investigate the association between existing household water quality, sanitation and hygiene (WASH) practices and severe cholera risk in a dense urban slum where cholera is highly endemic.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design, setting and participants<\/jats:title>\n                    <jats:p>We assembled a large prospective cohort within a cluster randomised trial evaluating the effectiveness of oral cholera vaccine. Our dynamic cohort population (n=193\u2009576) comprised individuals living in the \u2018non-intervention\u2019 clusters of the trial, and were followed over 4\u2009years. This study was conducted in a dense urban slum community of Dhaka, Bangladesh and cholera surveillance was undertaken in 12 hospitals serving the study area.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Primary outcome measure<\/jats:title>\n                    <jats:p>First severe cholera episode detected during follow-up period.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We applied a machine learning algorithm on a training subpopulation (n=96\u2009943) to develop a binary (\u2018better\u2019, \u2018not better\u2019) composite WASH variable predictive of severe cholera. The WASH rule was evaluated for performance in a separate validation subpopulation (n=96\u2009633). Afterwards, we used Cox regression models to evaluate the association between \u2018better\u2019 WASH households and severe cholera risk over 4 years in the entire study population.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The \u2018better\u2019 WASH rule found that water quality and access were the most significant factors associated with severe cholera risk. Members of \u2018better\u2019 WASH households, constituting one-third of the population, had a 47% reduced risk of severe cholera (95% CI: 29 to 69; p&lt;0.001), after adjusting for covariates. The protective association between living in a \u2018better\u2019 WASH household and severe cholera persisted in all age groups.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Salutary existing household WASH practices were associated with a significantly reduced long-term risk of severe cholera in an urban slum of Dhaka. These findings suggest that WASH adaptations already practised in the community may be important for developing and implementing effective and sustainable cholera control programmes in similar settings.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>\n                      This article is a re-analysis of data from a cluster randomized trial; can be found on ClinicalTrials.gov\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT01339845\">NCT01339845<\/jats:ext-link>\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2022-060858","type":"journal-article","created":{"date-parts":[[2022,9,21]],"date-time":"2022-09-21T14:05:03Z","timestamp":1663769103000},"page":"e060858","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":7,"title":["Are better existing WASH practices in urban slums associated with a lower long-term risk of severe cholera? A prospective cohort study with 4 years of follow-up in Mirpur, Bangladesh"],"prefix":"10.1136","volume":"12","clinical-trial-number":[{"clinical-trial-number":"nct01339845","registry":"10.18810\/clinical-trials-gov"}],"author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9585-3556","authenticated-orcid":false,"given":"Sophie","family":"Kang","sequence":"first","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fahima","family":"Chowdhury","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"},{"name":"Griffith University Menzies Health Institute Queensland, Nathan, Queensland, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juyeon","family":"Park","sequence":"additional","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tasnuva","family":"Ahmed","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Birkneh Tilahun","family":"Tadesse","sequence":"additional","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Md. Taufiqul","family":"Islam","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Deok Ryun","family":"Kim","sequence":"additional","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Justin","family":"Im","sequence":"additional","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Asma Binte","family":"Aziz","sequence":"additional","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masuma","family":"Hoque","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gideok","family":"Pak","sequence":"additional","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Farhana","family":"Khanam","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Faisal","family":"Ahmmed","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1107-0365","authenticated-orcid":false,"given":"Xinxue","family":"Liu","sequence":"additional","affiliation":[{"name":"Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1982-6879","authenticated-orcid":false,"given":"K","family":"Zaman","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ashraful Islam","family":"Khan","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jerome H","family":"Kim","sequence":"additional","affiliation":[{"name":"International Vaccine Institute, Gwanak-gu, The Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6043-7170","authenticated-orcid":false,"given":"Florian","family":"Marks","sequence":"additional","affiliation":[{"name":"Epidemiology, Public Health, and Impact Unit, International Vaccine Institute, Gwanak-gu, The Republic of Korea"},{"name":"Department of Medicine, University of Cambridge, Cambridge, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Firdausi","family":"Qadri","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John D","family":"Clemens","sequence":"additional","affiliation":[{"name":"Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh"},{"name":"International Vaccine Institute, Gwanak-gu, The Republic of Korea"},{"name":"Fielding School of Public Health, University of California, Los Angeles, California, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2022,9,21]]},"reference":[{"key":"2025121601222566000_12.9.e060858.1","unstructured":"Ritchie H , Roser M . 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