Wolf-Peter Schmidt

Interventions to improve water quality for preventing diarrhoea: systematic review and meta-analysis

Objective To assess the effectiveness of interventions to improve the microbial quality of drinking water for preventing diarrhoea. Design Systematic review. Data sources Cochrane Infectious Diseases Groups trials register, CENTRAL, Medline, Embase, LILACS; hand searching; and correspondence with experts and relevant organisations. Study selection Randomised and quasirandomised controlled trials of interventions to improve the microbial quality of drinking water for preventing diarrhoea in adults and in children in settings with endemic disease. Data extraction Allocation concealment, blinding, losses to follow-up, type of intervention, outcome measures, and measures of effect. Pooled effect estimates were calculated within the appropriate subgroups. Data synthesis 33 reports from 21 countries documenting 42 comparisons were included. Variations in design, setting, and type and point of intervention, and variations in defining, assessing, calculating, and reporting outcomes limited the comparability of study results and pooling of results by meta-analysis. In general, interventions to improve the microbial quality of drinking water are effective in preventing diarrhoea. Effectiveness was not conditioned on the presence of improved water supplies or sanitation in the study setting and was not enhanced by combining the intervention with instructions on basic hygiene, a water storage vessel, or improved sanitation or water supplies—other common environmental interventions intended to prevent diarrhoea. Conclusion Interventions to improve water quality are generally effective for preventing diarrhoea in all ages and in under 5s. Significant heterogeneity among the trials suggests that the level of effectiveness may depend on a variety of conditions that research to date cannot fully explain.

Water, sanitation and hygiene for the prevention of diarrhoea

Background Ever since John Snow’s intervention on the Broad St pump, the effect of water quality, hygiene and sanitation in preventing diarrhoea deaths has always been debated. The evidence identified in previous reviews is of variable quality, and mostly relates to morbidity rather than mortality. Methods We drew on three systematic reviews, two of them for the Cochrane Collaboration, focussed on the effect of handwashing with soap on diarrhoea, of water quality improvement and of excreta disposal, respectively. The estimated effect on diarrhoea mortality was determined by applying the rules adopted for this supplement, where appropriate. Results The striking effect of handwashing with soap is consistent across various study designs and pathogens, though it depends on access to water. The effect of water treatment appears similarly large, but is not found in few blinded studies, suggesting that it may be partly due to the placebo effect. There is very little rigorous evidence for the health benefit of sanitation; four intervention studies were eventually identified, though they were all quasi-randomized, had morbidity as the outcome, and were in Chinese. Conclusion We propose diarrhoea risk reductions of 48, 17 and 36%, associated respectively, with handwashing with soap, improved water quality and excreta disposal as the estimates of effect for the LiST model. Most of the evidence is of poor quality. More trials are needed, but the evidence is nonetheless strong enough to support the provision of water supply, sanitation and hygiene for all.

Effectiveness of a rural sanitation programme on diarrhoea, soil-transmitted helminth infection, and child malnutrition in Odisha, India: a cluster-randomised trial

BACKGROUND A third of the 2·5 billion people worldwide without access to improved sanitation live in India, as do two-thirds of the 1·1 billion practising open defecation and a quarter of the 1·5 million who die annually from diarrhoeal diseases. We aimed to assess the effectiveness of a rural sanitation intervention, within the context of the Government of Indias Total Sanitation Campaign, to prevent diarrhoea, soil-transmitted helminth infection, and child malnutrition. METHODS We did a cluster-randomised controlled trial between May 20, 2010, and Dec 22, 2013, in 100 rural villages in Odisha, India. Households within villages were eligible if they had a child younger than 4 years or a pregnant woman. Villages were randomly assigned (1:1), with a computer-generated sequence, to undergo latrine promotion and construction or to receive no intervention (control). Randomisation was stratified by administrative block to ensure an equal number of intervention and control villages in each block. Masking of participants was not possible because of the nature of the intervention. However, households were not told explicitly that the purpose of enrolment was to study the effect of a trial intervention, and the surveillance team was different from the intervention team. The primary endpoint was 7-day prevalence of reported diarrhoea in children younger than 5 years. We did intention-to-treat and per-protocol analyses. This trial is registered with ClinicalTrials.gov, number NCT01214785. FINDINGS We randomly assigned 50 villages to the intervention group and 50 villages to the control group. There were 4586 households (24,969 individuals) in intervention villages and 4894 households (25,982 individuals) in control villages. The intervention increased mean village-level latrine coverage from 9% of households to 63%, compared with an increase from 8% to 12% in control villages. Health surveillance data were obtained from 1437 households with children younger than 5 years in the intervention group (1919 children younger than 5 years), and from 1465 households (1916 children younger than 5 years) in the control group. 7-day prevalence of reported diarrhoea in children younger than 5 years was 8·8% in the intervention group and 9·1% in the control group (period prevalence ratio 0·97, 95% CI 0·83-1·12). 162 participants died in the intervention group (11 children younger than 5 years) and 151 died in the control group (13 children younger than 5 years). INTERPRETATION Increased latrine coverage is generally believed to be effective for reducing exposure to faecal pathogens and preventing disease; however, our results show that this outcome cannot be assumed. As efforts to improve sanitation are being undertaken worldwide, approaches should not only meet international coverage targets, but should also be implemented in a way that achieves uptake, reduces exposure, and delivers genuine health gains. FUNDING Bill & Melinda Gates Foundation, International Initiative for Impact Evaluation (3ie), and Department for International Development-backed SHARE Research Consortium at the London School of Hygiene & Tropical Medicine.

Comparing the performance of indicators of hand-washing practices in rural Indian households

Objective  To compare the results obtained from 26 proxy indicators of domestic hand‐washing practices with those obtained from direct, ‘structured’ observation of hand‐washing in a sample of 387 households and to assess the potential of these indicators for use in the evaluation of hygiene promotion campaigns.

Outbreak of Leptospirosis after Flood, the Philippines, 2009

After a typhoon in September 2009, an outbreak of leptospirosis occurred in Metro Manila, the Philippines; 471 patients were hospitalized and 51 (10.8%) died. A hospital-based investigation found risk factors associated with fatal infection to be older age, hemoptysis, anuria, jaundice, and delayed treatment with antimicrobial drugs.

Experimental Pretesting of Hand-Washing Interventions in a Natural Setting

OBJECTIVES We pretested interventions derived from different domains of behavior change theory to determine their effectiveness at increasing hand washing with soap in a natural setting. METHODS We installed wireless devices in highway service station restrooms to record entry and soap use. Two text-only messages for each of 7 psychological domains were compared for their effect on soap-use rates. We collected data on nearly 200 000 restroom uses. RESULTS The knowledge activation domain was most effective for women, with a relative increase in soap use of 9.4% compared with the control condition (P = .001). For men, disgust was the most effective, increasing soap use by 9.8% (P = .001). Disgust was not significantly better than the control condition for women, nor was knowledge activation for men. Messages based on social norms and social status were effective for both genders. CONCLUSIONS Our data show that unobtrusive observation of behavior in a natural setting can help identify the most effective interventions for changing behaviors of public health importance. The gender differences we found suggest that public health interventions should target men and women differently.

The effect of handwashing with water or soap on bacterial contamination of hands.

Handwashing is thought to be effective for the prevention of transmission of diarrhoea pathogens. However it is not conclusive that handwashing with soap is more effective at reducing contamination with bacteria associated with diarrhoea than using water only. In this study 20 volunteers contaminated their hands deliberately by touching door handles and railings in public spaces. They were then allocated at random to (1) handwashing with water, (2) handwashing with non-antibacterial soap and (3) no handwashing. Each volunteer underwent this procedure 24 times, yielding 480 samples overall. Bacteria of potential faecal origin (mostly Enterococcus and Enterobacter spp.) were found after no handwashing in 44% of samples. Handwashing with water alone reduced the presence of bacteria to 23% (p < 0.001). Handwashing with plain soap and water reduced the presence of bacteria to 8% (comparison of both handwashing arms: p < 0.001). The effect did not appear to depend on the bacteria species. Handwashing with non-antibacterial soap and water is more effective for the removal of bacteria of potential faecal origin from hands than handwashing with water alone and should therefore be more useful for the prevention of transmission of diarrhoeal diseases.

Three kinds of psychological determinants for hand-washing behaviour in Kenya

Washing hands with soap at the right times - primarily after contact with faeces, but also before handling food or feeding an infant - can significantly reduce the incidence of childhood infectious disease. Here, we present empirical results which substantiate a recent claim that washing hands can be the consequence of different kinds of psychological causes. Such causes can be divided into three kinds of control over behaviour: automatic or habitual responses, motivated or goal-driven behaviour to satisfy needs, and cognitive causes which reflect conscious concerns. Empirical results are based on 3-h-long structured observations of hand-washing behaviour in 802 nationally representative Kenyan households with children under five, and structured interviews with the primary female caretaker in these households, collected in March 2007. Factor analysis of questionnaire responses identified three psychological factors which are also significant predictors of observed hand-washing behaviour: having the habit of hand-washing at particular junctures during the day, the motivated need for personal or household cleanliness, and a lack of cognitive concern about the cost of soap use. These factors each represent a different kind of psychological cause. A perceived link between clean hands and sexual attractiveness also appeared in the factor analysis, but was not a determinant of actual behaviour. We also report evidence that those who express concern about the cost of soap use are those with relatively few economic resources. We suggest that those developing hygiene promotion programmes should consider the possible existence of multiple types of strategies for increasing hand-washing behaviour.

Intermittent slow sand filtration for preventing diarrhoea among children in Kenyan households using unimproved water sources: randomized controlled trial.

Objective  Measure effectiveness of intermittent slow sand filtration for reducing child diarrhoea among households using unimproved water sources in rural Kenya.

The effect of a soap promotion and hygiene education campaign on handwashing behaviour in rural India: a cluster randomised trial

Objective  To investigate the effectiveness of a hygiene promotion intervention based on germ awareness in increasing handwashing with soap on key occasions (after faecal contact and before eating) in rural Indian households.