{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T11:55:13Z","timestamp":1774353313645,"version":"3.50.1"},"reference-count":24,"publisher":"American Society of Tropical Medicine and Hygiene","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2016,12,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:p>Household members of cholera patients are at a 100 times higher risk of cholera infections than the general population because of shared contaminated drinking water sources and secondary transmission through poor household hygiene practices. In this study, we investigated the bactericidal concentration of free chlorine required to inactivate <jats:italic>Vibrio cholerae<\/jats:italic> in household drinking water in Dhaka, Bangladesh. In laboratory experiments, we found that the concentrations of free chlorine required to inactivate 10<jats:sup>5<\/jats:sup> colony-forming units (CFU)\/mL of <jats:italic>V. cholerae<\/jats:italic> serogroups O1 and O139 were 0.1 mg\/L and 0.2 mg\/L, respectively. The concentration of free chlorine generated by a single chlorine tablet (sodium dichloroisocyanurate [33 mg]) after a 30-minute reaction time in a 10-L sealed vessel containing Dhaka city municipal supply water was 1.8 mg\/L; and the concentration declined to 0.26 mg\/L after 24 hours. In field measurements, water collected from 165 households enrolled in a randomized controlled trial (RCT) of a chlorine and handwashing with soap intervention (Cholera-Hospital-Based-Intervention-for-7-Days [CHoBI7]), we observed significantly higher free chlorine concentrations in the 82 intervention arm households (mean = 1.12 mg\/L, standard deviation [SD] = 0.52, range = 0.07\u20132.6 mg\/L) compared with the 83 control households (0.017 mg\/L, SD = 0.01, range = 0\u20130.06 mg\/L) (<jats:italic>P<\/jats:italic> &lt; 0.001) during spot check visits. These findings suggest that point-of-use chlorine tablets present an effective approach to inactivate <jats:italic>V. cholerae<\/jats:italic> from drinking water in households of cholera patients in Dhaka city. This result is consistent with the findings from the RCT of CHoBI7 which found that this intervention led to a significant reduction in symptomatic cholera infections among household members of cholera patients and no stored drinking water samples with detectable <jats:italic>V. cholerae<\/jats:italic>.<\/jats:p>","DOI":"10.4269\/ajtmh.16-0420","type":"journal-article","created":{"date-parts":[[2016,10,4]],"date-time":"2016-10-04T03:29:34Z","timestamp":1475551774000},"page":"1299-1304","source":"Crossref","is-referenced-by-count":16,"title":["Chlorination of Household Drinking Water Among Cholera Patients' Households to Prevent Transmission of Toxigenic Vibrio cholerae in Dhaka, Bangladesh: CHoBI7 Trial"],"prefix":"10.4269","volume":"95","author":[{"given":"Mahamud-ur","family":"Rashid","sequence":"first","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christine Marie","family":"George","sequence":"additional","affiliation":[{"name":"Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shirajum","family":"Monira","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Toslim","family":"Mahmud","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zillur","family":"Rahman","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Munshi","family":"Mustafiz","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K. M.","family":"Saif-Ur-Rahman","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tahmina","family":"Parvin","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sazzadul Islam","family":"Bhuyian","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fatema","family":"Zohura","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Farzana","family":"Begum","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shwapon Kumar","family":"Biswas","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shamima","family":"Akhter","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaotong","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David","family":"Sack","sequence":"additional","affiliation":[{"name":"Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R. Bradley","family":"Sack","sequence":"additional","affiliation":[{"name":"Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Munirul","family":"Alam","sequence":"additional","affiliation":[{"name":"International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2795","reference":[{"key":"ref1","series-title":"Diarrhoeal Disease","author":"World Health Organization","year":"2013"},{"key":"ref2","series-title":"PLoS Negl Trop Dis","first-page":"e0003832","article-title":"Updated global burden of cholera in endemic countries","volume":"9","author":"Ali","year":"2015"},{"key":"ref3","series-title":"Am J Trop Med Hyg","first-page":"708","article-title":"Shifting prevalence of major diarrheal pathogens in patients seeking hospital care during floods in 1998, 2004, and 2007 in 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