Deborah Blum

Bio: Deborah Blum is an academic researcher from University of London. The author has contributed to research in topics: Sanitation & Population. The author has an hindex of 7, co-authored 7 publications receiving 532 citations. Previous affiliations of Deborah Blum include UNICEF.

Measuring the Impact of Water Supply and Sanitation Investments on Diarrhoeal Diseases: Problems of Methodology

Abstract: A review of the published literature on the impact of water supply and/or excreta disposal facilities on diarrhoeal diseases, or on infections related to diarrhoea, reveals several methodological problems that hamper the drawing of definitive conclusions from these studies. This paper examines eight of these methodological problems: lack of adequate control, the one to one comparison, confounding variables, health indicator recall, health indicator definition, failure to analyse by age, failure to record usage, and the seasonality of impact variables. It is suggested that an evaluation of the impact on health of environmental interventions may best be undertaken by the combined efforts of engineers, social scientists and epidemiologists in 'opportunistic' settings and that the intervening behavioural processes so necessary for health impact to occur should be a primary focus of such evaluations.

The Imo State (Nigeria) Drinking Water Supply and Sanitation Project, 2. Impact on dracunculiasis, diarrhoea and nutritional status.

Abstract: Morbidity due to dracunculiasis (guinea worm disease) and diarrhoea in persons of all ages, and nutritional status of young children, were used as health impact indicators in the evaluation of the Imo State Drinking Water Supply and Sanitation Project in south-eastern Nigeria. Data were collected using repeated cross-sectional surveys and longitudinal follow-up. The study area was found to have a low level of endemicity of dracunculiasis. While no impact could be demonstrated on overall period or point prevalence rates in the cross-sectional surveys, a prospective longitudinal survey showed a significant reduction in the percentage of person-fortnights positive for dracunculiasis in areas served by the project, while the control areas showed no such change. In the cross-sectional surveys it was found that, in the project villages, those persons drinking only borehole water had significantly lower period prevalence rates one year later than others. Moreover, those living further from the nearest borehole had higher rates of dracunculiasis. An impact of the project on diarrhoea morbidity was found only in limited sub-groups of the population. A greater association with water availability rather than quality was suggested for rates in young children. The prevalence of wasting (less than 80% weight-for-height) among children aged less than 3 years decreased significantly over time in all 3 intervention villages; there was no such decline in the control villages.

The epidemiology of acute diarrhoea in a rural community in Imo State, Nigeria.

Abstract: As part of an evaluation of a water supply and sanitation project, a baseline cross-sectional study of diarrhoea, and its putative risk factors, was conducted in 5 villages in Imo State, Nigeria. Data were collected from 4641 and 5920 persons during surveys in the dry and wet seasons, respectively. 8 d period prevalence rates for diarrhoea ranged from 5 to 50%, with the highest rates occuring in the 6 to 23 month age group. Diarrhoea was associated with up to 75% of all illnesses in young children and with about 20% in adults. Risk factors included lower socio-economic status, an unclean domestic environment, use of non-purified water, absence of soap, and feeding methods other than exclusive breast-feeding in the early months of infancy. These results suggest that the education component of water supply and sanitation projects should emphasize personal and domestic hygiene and infant feeding.

The Imo State (Nigeria) Drinking Water Supply and Sanitation Project, 1. Description of the project, evaluation methods, and impact on intervening variables.

Abstract: A health impact evaluation was conducted in conjunction with the Imo State Drinking Water Supply and Sanitation Project in Nigeria. The project consisted of a package of water supply, sanitation, and health and hygiene education given by village-based workers. The evaluation was a quasi-experimental study covering pre-, peri- and post-intervention periods. Data were collected from 3 intervention and 2 control villages. Baseline surveys indicated that the intervention and control areas were similar with respect to most socio-demographic variables. Use of the improved water supply was high, although this was influenced by borehole-to-population ratios and household-to-borehole distances. Water collection time was consequently greatly reduced. Data from a small sample of households showed that borehole water became heavily contaminated during collection and storage, and that there was no significant change in consumption of water per person. Adults in 46% of household units in the intervention area were using ventilated improved pit latrines by the end of the study period. Use by young children (2-5 years old), however, was low. Limitations in the success of the health education component of the project were found. Although changes were found in knowledge, attitudes and practices related to water and sanitation, and in management of childhood diarrhoea, this occurred in both the intervention and control areas.

Disability from dracunculiasis: effect on mobility.

Abstract: A study was conducted in northeastern Imo State to define the disability and restriction of mobility associated with dracunculiasis. The study was part of an evaluation of the UNICEF-assisted Drinking Water Supply and Sanitation Project in Imo State, Nigeria. A sample of household units (100 in year 1, 195 in year 2) was visited every two weeks to determine who was affected by dracunculiasis and to characterize the extent of related disability. The average duration of symptoms was 12.7 weeks (range 3-29 weeks). Fifty eight per cent of all episodes of disease resulted in severe disability (with the individual unable to leave the compound) lasting a mean of 4.2 weeks (range 2-12). The mean period of severe disability was significantly higher for those aged 50 years and over than for those less than 50 years old. In the area studied, the disease occurred during the peak yam and rice harvest time and the period of preparation for the planting season. This is the first study to document systematically and prospectively the marked restriction of normal activity in affected individuals and the long duration of the disability. These findings can assist in improving estimates of the costs associated with dracunculiasis and of potential economic benefits if the disease were eradicated.

Water sanitation and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and meta-analysis.

Abstract: Many studies have reported the results of interventions to reduce illness through improvements in drinking water, sanitation facilities, and hygiene practices in less developed countries. There has, however, been no formal systematic review and meta-analysis comparing the evidence of the relative effectiveness of these interventions. We developed a comprehensive search strategy designed to identify all peer-reviewed articles, in any language, that presented water, sanitation, or hygiene interventions. We examined only those articles with specific measurement of diarrhoea morbidity as a health outcome in non-outbreak conditions. We screened the titles and, where necessary, the abstracts of 2120 publications. 46 studies were judged to contain relevant evidence and were reviewed in detail. Data were extracted from these studies and pooled by meta-analysis to provide summary estimates of the effectiveness of each type of intervention. All of the interventions studied were found to reduce significantly the risks of diarrhoeal illness. Most of the interventions had a similar degree of impact on diarrhoeal illness, with the relative risk estimates from the overall meta-analyses ranging between 0·63 and 0·75. The results generally agree with those from previous reviews, but water quality interventions (point-of-use water treatment) were found to be more effective than previously thought, and multiple interventions (consisting of combined water, sanitation, and hygiene measures) were not more effective than interventions with a single focus. There is some evidence of publication bias in the findings from the hygiene and water treatment interventions.

Effect of washing hands with soap on diarrhoea risk in the community: a systematic review

Abstract: We set out to determine the impact of washing hands with soap on the risk of diarrhoeal diseases in the community with a systematic review with random effects meta-analysis Our data sources were studies linking handwashing with diarrhoeal diseases Seven intervention studies, six case-control, two cross-sectional, and two cohort studies were located from electronic databases, hand searching, and the authors' collections The pooled relative risk of diarrhoeal disease associated with not washing hands from the intervention trials was 188 (95% CI 131-268), implying that handwashing could reduce diarrhoea risk by 47% When all studies, when only those of high quality, and when only those studies specifically mentioning soap were pooled, risk reduction ranged from 42-44% The risks of severe intestinal infections and of shigellosis were associated with reductions of 48% and 59%, respectively In the absence of adequate mortality studies, we extrapolate the potential number of diarrhoea deaths that could be averted by handwashing at about a million (11 million, lower estimate 05 million, upper estimate 14 million) Results may be affected by the poor quality of many of the studies and may be inflated by publication bias On current evidence, washing hands with soap can reduce the risk of diarrhoeal diseases by 42-47% and interventions to promote handwashing might save a million lives More and better-designed trials are needed to measure the impact of washing hands on diarrhoea and acute respiratory infections in developing countries

The magnitude of the global problem of diarrhoeal disease: a ten-year update.

Abstract: In order to update global estimates of diarrhoeal morbidity and mortality in developing countries, we carried out a review of articles published from 1980 to the present and calculated median estimates for the incidence of diarrhoea and diarrhoeal mortality among under-5-year-olds The incidence of diarrhoea obtained (26 episodes per child per year) was virtually the same as that estimated by Snyder & Merson in 1982, while the global mortality estimate was lower (33 million deaths per year; range, 15-51 million) The mortality estimate is based on a small number of active surveillance and prospective studies, and thus associated with a large degree of uncertainty, reflecting the weakness of the global database However, many surveys reporting reductions in mortality in several locations are consistent with a decreased estimate for mortality More accurate execution of WHO survey methods, including population-based sampling in representative locations, and repeat surveys every 5 years, are needed to monitor the progress of diarrhoeal disease control programmes and trends in diarrhoeal morbidity and mortality over time

Household drinking water in developing countries: a systematic review of microbiological contamination between source and point‐of‐use

Abstract: Summary objective To assess the extent and causes of microbiological contamination of household drinking water between source and point-of-use in developing countries. methods A systematic meta-analysis of 57 studies measuring bacteria counts for source water and stored water in the home to assess how contamination varied between settings. results The bacteriological quality of drinking water significantly declines after collection in many settings. The extent of contamination after water collection varies considerably between settings, but is proportionately greater where faecal and total coliform counts in source water are low. conclusions Policies that aim to improve water quality through source improvements may be compromised by post-collection contamination. Safer household water storage and treatment is recommended to prevent this, together with point-of-use water quality monitoring.