Sodium dichloroisocyanurate tablets for routine treatment of household drinking water in periurban Ghana: a randomized controlled trial

Abstract

We conducted a randomized, placebo-controlled, triple-blinded trial to determine the health impact of daily use of sodium dichloroisocyanurate (NaDCC) tablets for household drinking water treatment in periurban Ghana. We randomized 240 households (3,240 individuals) to receive either NaDCC or placebo tablets. All households received a 20-liter safe water storage vvessel. Over 12 weeks, 446 diarrhea episodes (2.2%) occurred in intervention and 404 (2.0%) in control households (P = 0.38). Residual free chlorine levels indicated appropriate tablet use. Escherichia coli was found in stored water at baseline in 96% of intervention and 88% of control households and at final evaluation in 8% of intervention and 54% of control households (P = 0.002). NaDCC use did not prevent diarrhea but improved water quality. Diarrhea rates were low and water quality improved in both groups. Safe water storage vessels may have been protective. A follow-up health impact study of NaDCC tablets is warranted.

Figure 1.

Given the intention-to-treat analysis, we analyzed all households and participants for the full time of surveillance (12.5 weeks) despite attrition in the study.

Figure 2.

Percent of diarrhea episodes per total number of observations in intervention and control groups, by surveillance visit (N = 3240).

Figure 3.

Percent of intervention and control households with ≥ 0.2 g/mL of free chlorine in stored water, by surveillance visit (N = 240). * Data was not obtained for surveillance visit number 25 due to constraints in the field.