Combining drinking water treatment and hand washing for diarrhoea prevention, a cluster randomised controlled trial

Abstract

Summaryobjectives To evaluate the effectiveness of point of use water treatment with flocculent-disinfectant on reducing diarrhoea and the additional benefit of promoting hand washing with soap.methods The study was conducted in squatter settlements of Karachi, Pakistan, where diarrhoea is a leading cause of childhood death. Interventions were randomly assigned to 47 neighbourhoods. Households in 10 neighbourhoods received diluted bleach and a water vessel; nine neighbourhoods received soap and were encouraged to wash hands; nine neighbourhoods received flocculent-disinfectant water treatment and a water vessel; 10 neighbourhoods received disinfectant-disinfectant water treatment and soap and were encouraged to wash hands; and nine neighbourhoods were followed as controls. Field workers visited households at least once a week from April to December 2003 to promote use of the interventions and to collect data on diarrhoea.results Study participants in control neighbourhoods had diarrhoea on 5.2% of days. Compared to controls, participants living in intervention neighbourhoods had a lower prevalence of diarrhoea: 55% (95% CI 17%, 80%) lower in bleach and water vessel neighbourhoods, 51% (95% CI 12%, 76%) lower in hand washing promotion with soap neighbourhoods, 64% lower (95% CI 29%, 90%) in disinfectant-disinfectant neighbourhoods, and 55% (95% CI 18%, 80%) lower in disinfectantdisinfectant plus hand washing with soap neighbourhoods.conclusions With an intense community-based intervention and supplies provided free of cost, each of the home-based interventions significantly reduced diarrhoea. There was no benefit by combining hand washing promotion with water treatment.

Sodium Dichloroisocyanurate Tablets for Routine Treatment of Household Drinking Water in Periurban Ghana: A Randomized Controlled Trial

“…The lack of health impact in the context of successful treatment of stored drinking water was not consistent with results of previous studies of other chlorine-based, point-of-use water treatment interventions. 7,9,[12][13][14][15][16] There are several possible explanations for the observed lack of health impact. First, it is possible that disinfected stored water does not prevent diarrhea.…”

“…[2][3][4][5]7,9,[12][13][14][15][16] A recent meta-epidemiological study assessed the evidence for bias in controlled trials due to lack of blinding 34 and, although the review did not specifically assess point-ofuse water treatment intervention trials, it did estimate that trials with subjective outcomes exaggerated the actual effect of those outcomes by approximately 25%. Thus, even if the pooled estimate of the effect of household water treatment were adjusted by this factor of 25%, the protective effect would still be greater than 30%.…”

“…For this reason, a number of household water treatment technologies have been developed, tested, and disseminated to protect the health of populations lacking access to safe water. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] One of these household water treatment technologies is sodium dichloroisocyanurate (NaDCC) tablets, an alternative to sodium hypochlorite (NaOCl) solution, which is produced and distributed in many countries for water treatment. 17 Both NaDCC tablets and NaOCl solution disinfect water by releasing free available chlorine in the form of hypochlorous acid, which is an effective microbicide against a wide range of bacteria, viruses, and parasites.…”

Water And Sanitation in Developing Countries: Including Health in the Equation

“…An additional challenge is determining whether health outcomes are primarily due to POU treatment or confounding factors, such as hand washing, education, economic wellbeing, and culture. For example, a drinking-water and hand-washing study in squatter settlements in Karachi, Pakistan, found no significant difference in reduction of daily longitudinal prevalence of diarrhea among households that used POU technologies alone (64%), hand washing alone (51%), and a combination of POU treatments and hand washing with soap (55%) (30). Therefore, additional comparative and longitudinal health studies are required to determine which technologies are most effective.…”

The Variability of Childhood Diarrhea in Karachi, Pakistan, 2002–2006

“…[13][14][15] During these studies, the neighborhood water and sanitary infrastructure and food supply remained largely constant. We combined data from these separate studies to quantify the variation in diarrhea prevalence over time.…”