Estimating the impact of unsafe water,sanitation and hygiene on the global burden of disease: evolving and alternative methods

The 2010 global burden of disease (GBD) study represents the latest effort to estimate the global burden of disease and injuries and the associated risk factors. Like previous GBD studies, this latest iteration reflects a continuing evolution in methods, scope and evidence base. Since the first GBD Study in 1990, the burden of diarrhoeal disease and the burden attributable to inadequate water and sanitation have fallen dramatically. While this is consistent with trends in communicable disease and child mortality, the change in attributable risk is also due to new interpretations of the epidemiological evidence from studies of interventions to improve water quality. To provide context for a series of companion papers proposing alternative assumptions and methods concerning the disease burden and risks from inadequate water, sanitation and hygiene, we summarise evolving methods over previous GBD studies. We also describe an alternative approach using population intervention modelling. We conclude by emphasising the important role of GBD studies and the need to ensure that policy on interventions such as water and sanitation be grounded on methods that are transparent, peer‐reviewed and widely accepted.     

Use of nutritional and water hygiene packages for diarrhoeal prevention among HIV‐exposed infants in Lilongwe,Malawi: an evaluation of a pilot prevention of mother‐to‐child transmission post‐natal care service

Objective To evaluate a pilot prevention of mother‐to‐child transmission post‐natal programme in Lilongwe, Malawi, through observed retention and infant diarrhoeal rates. Methods Free fortified porridge and water hygiene packages were offered to mothers to encourage frequent post‐natal visits and to reduce diarrhoeal rates in infants on replacement feeding. Participant retention and infant health outcome were assessed. Results Of 474 patients enrolled, 357 (75.3%) completed 3‐month follow‐up visits. Ninety‐nine percent of women reported hygiene package use, and only 17.7% (95% CI 13.8–22.0%) of the infants had diarrhoea at least once over the 3‐month period. Being 12 months or younger, confirmed HIV positive, access to tap water, and having a mother with diarrhoea were all associated with increased risk of infant diarrhoea. Conclusion The majority of participants adhered to their scheduled visits and retention was favourable, possibly because of the introduction of hygiene and nutrition incentives. The infant diarrhoeal rate was low, suggesting benefits of regular medical care with hygiene package usage and reliable replacement feeding options. Continuation and expansion of the programme would allow further studies and improve the post‐natal care of HIV‐exposed infants in Malawi and in other resource‐constrained countries.     

Assessing the impact of a school-based water treatment, hygiene and sanitation programme on pupil absence in Nyanza Province, Kenya: a cluster-randomized trial

Objectives There has been increased attention to access to water, sanitation and hygiene (WASH) at schools in developing countries, but a dearth of empirical studies on the impact. We conducted a cluster‐randomized trial of school‐based WASH on pupil absence in Nyanza Province, Kenya, from 2007 to 2008. Methods Public primary schools nested in three geographical strata were randomly assigned and allocated to one of three study arms [water treatment and hygiene promotion (WT & HP), additional sanitation improvement, or control] to assess the effects on pupil absence at 2‐year follow‐up. Results We found no overall effect of the intervention on absence. However, among schools in two of the geographical areas not affected by post‐election violence, those that received WT and HP showed a 58% reduction in the odds of absence for girls (OR 0.42, CI 0.21–0.85). In the same strata, sanitation improvement in combination with WT and HP resulted in a comparable drop in absence, although results were marginally significant (OR 0.47, 0.21–1.05). Boys were not impacted by the intervention. Conclusion School WASH improvements can improve school attendance for girls, and mechanisms for gendered impacts should be explored. Incomplete intervention compliance highlights the challenges of achieving consistent results across all settings.     

Hygiene and sanitation practices amongst residents of three long‐term refugee camps in Thailand,Ethiopia and Kenya

Objective To further the understanding of sanitation and hygiene in long‐term camp populations. Methods Data were collected by structured observation of handwashing (126 households), a questionnaire on sanitation, hygiene and household characteristics (1089 households) and discussions with mothers. Random walk algorithms were used to select households for observation and survey. Respondents for qualitative methods were a convenience sample. Results Across all key handwash occasions [excluding events with no handwash (n = 275)], soap was used for 30% of handwashes. After latrine use, both hands were washed with soap on 20% of occasions observed. Availability of soap in households differed across sites and mirrored the extent to which it was distributed free of charge. Qualitative data suggested lack of free soap as a barrier to ‘safe’ handwashing. Laundry was the priority for soap. In Ethiopia and Kenya, open defecation was practised by a significant minority and was more prevalent amongst households of rural origin. In Ethiopia, open defecation was significantly more prevalent amongst women. Conclusions Despite continuing hygiene education, rates of ‘safe’ handwashing are sub‐optimal. Soap scarcity in some households and the prioritisation of laundry are barriers to safe practice. Heterogeneity with respect to education and place of origin may need to be taken into account in the design of improved interventions.     

Direct observation of hygiene in a Peruvian shantytown: not enough handwashing and too little water

Objective To document frequency of hygiene practices of mothers and children in a shantytown in Lima, Peru. Methods Continuous monitoring over three 12‐h sessions in households without in‐house water connections to measure: (i) water and soap use of 32 mothers; (ii) frequency of interrupting faecal‐hand contamination by washing; and (iii) the time until faecal‐hand contamination became a possible transmission event. Results During 1008 h of observation, 55% (65/119) of mothers’ and 69% (37/54) of children’s faecal‐hand contamination events were not followed within 15 min by handwashing or bathing. Nearly 40% (67/173) of faecal‐hand contamination events became possible faecal‐oral transmission events. There was no difference in the time‐until‐transmission between mothers and children (P = 0.43). Potential transmission of faecal material to food or mouth occurred in 64% of cases within 1 h of hand contamination. Mean water usage (6.5 l) was low compared to international disaster relief standards. Conclusions We observed low volumes of water usage, inadequate handwashing, and frequent opportunities for faecal contamination and possible transmission in this water‐scarce community.     

Disease control and health systems in low‐ and middle‐income countries: enhancing positive interrelation

There is a growing interest in improving the relationship between disease control programmes and the rest of the health system in low‐ and middle‐income countries. This short study seeks to contribute to this movement by providing a multi‐dimensional approach for policy‐makers and researchers. It recognizes the different and often conflicting perspectives in health systems held by stakeholders. Two such perspectives are those of disease control programmes and health systems. Both are based on perceived health needs and put forward requirements on each other through resource demands and organizational needs. Failure to reconcile these perspectives can lead to health system fragmentation. This study proposes a framework to address the importance of mutual support across stakeholder perspectives, striving to understand and analyse the consequences of their reciprocal views. In doing this, the study stresses the importance of common understanding around health system values, the political interplay between stakeholders, the contextual setting and the need to integrate research and capacity development in this area.     

Non‐typhoidal Salmonella rates in febrile children at sites in five Asian countries

There is increased recognition of non‐typhoidal Salmonella (NTS) as a major cause of severe febrile illness in sub‐Saharan Africa. However, little is known about community‐based incidence of NTS in Asia. In a multicentre, community‐based prospective Salmonella surveillance study, we identified a total of six NTS cases: three in Karachi, Pakistan, one in Kolkata, India, and two in North Jakarta, Indonesia. No NTS cases were identified in Hechi, People’s Republic of China, and Hue, Viet Nam. Three cases were in children under 3 years, and one case was in a child aged 10 years and one in a child aged 15 years. Only one case was an adult (29 years). The highest incidence of NTS infection was in Karachi (7.2 culture‐proven NTS cases per 100 000 person years in age group of 2–15 years). However, in comparison with sub‐Saharan Africa, the NTS burden in Asia appears rather limited.