Household water treatment using sodium dichloroisocyanurate (NaDCC) tablets: a randomized, controlled trial to assess microbiological effectiveness in Bangladesh.

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.