title: Household water treatment using sodium dichloroisocyanurate (NaDCC) tablets: a randomized, controlled trial to assess microbiological effectiveness in Bangladesh.
abstract: We assessed the microbiologic effectiveness of sodium dichloroisocyanurate (NaDCC) tablets used on a routine basis at the household level by a vulnerable population. In a 4-month trial in Dhaka, Bangladesh, one half of the 100 participating households received NaDCC tablets and instructions on how to use the same; the other one half received a placebo and the same instructions. Monthly samples of stored drinking water from intervention households were significantly lower in thermotolerant coliforms (TTCs) than those of control households (geometric mean, 2.8 [95% CI: 2.2, 3.6] versus 604.1 [95% CI: 463.2, 787.9]; P < 0.0001). While 61.7% (116/188) of samples from the intervention households met World Health Organization (WHO) guidelines for 0 TTCs in drinking water, none of the 191 samples from control households met such a benchmark. Residual free chlorine in water samples suggested that householders consistently used the intervention, but 11.7% of samples exceeded the WHO guideline value of 5.0 mg/L, underscoring the need to ensure that tablet dose and vessel size are compatible.
authors.affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. thomas.clasen@lshtm.ac.uk
authors.forename: Thomas
authors.initials: T
authors.lastname: Clasen
authors.forename: Tanveer F
authors.initials: TF
authors.lastname: Saeed
authors.forename: Sophie
authors.initials: S
authors.lastname: Boisson
authors.forename: Paul
authors.initials: P
authors.lastname: Edmondson
authors.forename: Oleg
authors.initials: O
authors.lastname: Shipin
mesh_terms: D001459:Bangladesh; D002713:Chlorine; D006801:Humans; D014227:Triazines / Q000008:administration & dosage / Q000494:pharmacology*; D014867:Water / Q000737:chemistry; D014871:Water Microbiology / Q000592:standards*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000592:standards
chemical_list: D014227:Triazines; D014867:Water; D002713:Chlorine; C011765:troclosene