Risk reduction assessment of waterborne Salmonella and Vibrio by a chlorine contact disinfectant point-of-use device. International Journal of Hygiene and Environmental Health, 4 October 2012.
Angela D. Coulliette, et al.
Unsafe drinking water continues to burden developing countries despite improvements in clean water delivery and sanitation, in response to Millennium Development Goal 7. Salmonella serotype Typhi and Vibrio cholerae bacteria can contaminate drinking water, causing waterborne typhoid fever and cholera, respectively.
Householdwatertreatment (HWT) systems are widely promoted to consumers in developing countries but it is difficult to establish their benefits to the population for specific disease reduction. This research uses a laboratory assessment of halogenated chlorine beads treating contaminated water to inform a quantitative microbial risk assessment (QMRA) of S. Typhi and V. cholerae disease in a developing country community of 1000 people.
Laboratory challenges using seeded well water resulted in log10 reductions of 5.44 (±0.98 standard error (SE)) and 6.07 (±0.09 SE) for Salmonella serotype Typhimurium and V. cholerae, respectively. In well water with 10% sewage and seeded bacteria, the log10 reductions were 6.06 (±0.62 SE) and 7.78 (±0.11 SE) for S. Typhimurium and V. cholerae, respectively. When one infected individual was contributing to the water contamination through fecal material leaking into the water source, the risk of disease associated with drinking untreated water was high according to a Monte Carlo analysis: a median of 0.20 (interquartile range [IQR] 0.017–0.54) for typhoid fever and a median of 0.11 (IQR 0.039–0.20) for cholera.
If water was treated, risk greatly decreased, to a median of 4.1 × 10−7 (IQR 1.6 × 10−8 to 1.1 × 10−5) for typhoid fever and a median of 3.5 × 10−9 (IQR 8.0 × 10−10 to 1.3 × 10−8) for cholera. Insights on risk management policies and strategies for public health workers were gained using a simple QMRA scenario informed by laboratory assessment of HWT.
Determining the differential preferences of users of two fluoride-free water options in rural Ethiopia. JOURNAL OF PUBLIC HEALTH 2012, DOI: 10.1007/s10389-012-0537-4
Alexandra C. Huber and Hans-Joachim Mosler
Aim – In the Ethiopian Rift Valley, 8.5 million people depend on water sources with excessive fluoride. In one rural village, a fluoride-removal community filter was implemented; a personalized reminder was distributed to change people’s behavior and increase the usage of the in-village community filter. During this promotion phase, an alternative fluoride-removal option was installed in a neighboring village. This study examines psychological factors that explain the differences in preference between the two options and their influence on the usage of the different sources. In addition, the effectiveness of the applied behavior change technique, a personalized reminder, on the use of the in-village community filter was analyzed.
Subject and methods – In a complete longitudinal survey, 180 households, with access to both mitigation options, were interviewed through structured, face-to-face interviews. Logistic regressions were carried out to reveal factors predicting the usage of the two mitigation options and the effect of the implemented behavior change intervention.
Results – The results showed that the better the taste, the lower the effort and the lower the costs for using the in-village community filter are perceived; in addition, the lower the perceived vulnerability to contract disease, the more the in-village community filter is used. Moreover, it was found that the personalized reminder also had a positive effect on the usage of the in-village mitigation option.
Conclusion – Based on the results, possible recommendations for practitioners and researchers are made to help plan and implement mitigation options.
Access to Safe Water for the Bottom of Pyramid: Strategies for Disseminating Technology Research Benefits. Technology Packaging Study, 2012.
Society for Technology and Action for Rural Advancement (TARA)
The Phase 1 study highlighted that there are (Nano) technologies that can effectively purify water and there is a large population in need of these technologies. However, there is a disconnect between the two.
A technology packaging study was undertaken to understand the supply chain and the life cycle of the products in different domains so that the findings can be incorporated in the final pilot roll out and try to look into various aspects like product design, standards and practices for quality assurance, awareness, safety aspects from the point of view of each stakeholder.
The first chapter introduces the initiative and lays the context for the study. The second chapter maps short listed nano based technologies both at the research and market stages. The pilot will take forward some of these technologies. Chapter 3 traces the life cycle of a water filter right from the research stage upto disposal. It also highlights key issues that need to be considered while planning an intervention. Chapter 4 further expounds on innovations undertaken by various stakeholders to enable access to the Bottom of the Pyramid (BoP). The last chapter throws up pointers for the stakeholders to improve access.
Assessing Water Filtration and Safe Storage in Households with Young Children of HIV-Positive Mothers: A Randomized, Controlled Trial in Zambia, PLoS ONE, Oct 2012.
Rachel Peletz, et al.
Background – Unsafe drinking water presents a particular threat to people living with HIV/AIDS (PLHIV) due to the increased risk of opportunistic infections, diarrhea-associated malabsorption of essential nutrients, and increased exposure to untreated water for children of HIV-positive mothers who use replacement feeding to reduce the risk of HIV transmission. This population may particularly benefit from an intervention to improve water quality in the home.
Methods and Findings – We conducted a 12-month randomized, controlled field trial in Zambia among 120 households with children <2 years (100 with HIV-positive mothers and 20 with HIV-negative mothers to reduce stigma of participation) to assess a high-performance water filter and jerry cans for safe storage. Households were followed up monthly to assess use, drinking water quality (thermotolerant coliforms (TTC), an indicator of fecal contamination) and reported diarrhea (7-day recall) among children <2 years and all members of the household.
Because previous attempts to blind the filter have been unsuccessful, we also assessed weight-for-age Z-scores (WAZ) as an objective measure of diarrhea impact. Filter use was high, with 96% (596/620) of household visits meeting the criteria for users. The quality of water stored in intervention households was significantly better than in control households (3 vs. 181 TTC/100 mL, respectively, p<0.001). The intervention was associated with reductions in the longitudinal prevalence of reported diarrhea of 53% among children <2 years (LPR = 0.47, 95% CI: 0.30–0.73, p = 0.001) and 54% among all household members (LPR = 0.46, 95% CI: 0.30–0.70, p<0.001). While reduced WAZ was associated with reported diarrhea (−0.26; 95% CI: −0.37 to −0.14, p<0.001), there was no difference in WAZ between intervention and control groups.
Conclusion - In this population living with HIV/AIDS, a water filter combined with safe storage was used correctly and consistently, was highly effective in improving drinking water quality, and was protective against diarrhea.
What can hand hygiene do for the world? October 2012.
Katie Greenland, Sandy Cairncross and Val Curtis. Environmental Health Group, Department of Disease Control, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, United Kingdom
Handwashing with soap is regarded as one of the most cost-effective interventions to improve public health [1]. This is mainly because the simple action of washing hands with soap can interrupt the transmission of the pathogens that cause diarrhoea and pneumonia, the two biggest killers of children under-five [2]. The latest estimates of the global causes of child mortality attribute 0.751 million (uncertainty range 0.538 – 1.031 million) deaths among children aged 1 to 59 months a year to diarrhoea and 1.071 million (uncertainty range 0.977 – 1.176 million) to pneumonia [2]. Reviews of epidemiological studies suggest that universal practice of handwashing with soap could reduce the risk of severe diarrhoea by 48% and the risk of any diarrhoea by 47% [3]. A further review [4], updated by the authors to include findings from a subsequent study [5, 6] concludes that handwashing with soap could reduce the risk of lower respiratory tract infections like pneumonia by up to 23%.
In 2003, Curtis and Cairncross estimated the number of deaths due to diarrhoea preventable by handwashing with soap [3]. The subsequent growth of evidence quantifying the impact of handwashing with soap on respiratory infections, and the recent publication of updated mortality estimates provide the opportunity to update estimates of the number of lives that could be saved by handwashing. Assuming that the number of lives saved is proportional to the reduction in disease risk as described by Curtis and Cairncross (2003) [3] and other authors [7, 8], we estimate that the lives of 0.603 million children aged 1-59 months could be saved annually from diarrhoea and pneumonia by handwashing with soap (table 1).
We do not include in this estimate the lives of neonates that could be saved by handwashing. Given that around 33% of the 3.1 million annual deaths occurring among neonates are due to infectious causes [2], and that clean birth and postnatal practices – of which handwashing with soap is a component – have been estimated to reduce death due to sepsis and tetanus by up to 40% [9], the number of lives that could be saved by handwashing with soap may well exceed the estimates we report here. In addition to saving lives, a plethora of other health benefits have been attributed to handwashing with soap, including reductions in health-care associated infections [10], puerperal sepsis [11], skin infections [5], eye infections [12], including trachoma (the latter health improvements come from face washing combined with antibiotic usage) [13], and diarrhoea, co-infections and disease progression among people living with HIV/AIDS [14, 15]. Other benefits include increased school attendance as a result of less episodes of illness [16-18] and possible improvements in child growth and development as a result of improved nutritional status (hypothesised to be mediated via reduction in diarrhoea and environmental enteropathy) [19, 20]. These benefits are described more fully elsewhere [21].
The latest Biosand Filter Project Implementation materials (2012) are now available online!
What you will find there:
- Biosand Filter Construction Manual – with updated information, in a great new illustrated, easy to read format!
- Mold Package – instructions for how to construct steel molds (Version 10 With Ledge, Version 10 No Ledge, Version 9), tips for converting a Version 9 mold into a Version 10 mold, Tips for checking the quality of a mold, Guidelines for constructing a round steel mold, and links to two instructional videos about how to build a mold. A Welder Picture Book to accompany the mold instructions can be downloaded separately (due to its size).
- Sand Package – instructions for how to do a Sand Grain Size Analysis (graphing by hand) and extra graphing worksheets, a Sand Grain Size Analysis Calculator (excel), instructions for making mini-sieve sets for doing a sand grain size analysis, Instructions for constructing sand sieves (full size for filter construction), and a one-page info sheet on specifications for 0.7mm screen.
- BSF Case Studies – three BSF case studies (more to be added in the coming year!)
French and Spanish materials are currently being translated. They will be updated on the website when they are complete.
Also check out our new BSF page on the CAWST website! If you haven’t signed up for a BSF Google Group, consider becoming a member to get the latest information and support from a community of biosand filter implementers! Links to the two groups (Construction and Implementation) are available here.
Please contact CAWST if you require any other materials or support.
Am. J. Trop. Med. Hyg., 87(4), 2012, pp. 594–601
Impact of a Hygiene Curriculum and the Installation of Simple Handwashing and Drinking Water Stations in Rural Kenyan Primary Schools on Student Health and Hygiene Practices
Minal K. Patel,* Julie R. Harris, Patricia Juliao, Benjamin Nygren, Vincent Were, Steve Kola, Ibrahim Sadumah,Sitnah Hamidah Faith, Ronald Otieno, Alfredo Obure,† Robert M. Hoekstra, and Robert Quick
Epidemic Intelligence Service and Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention, Atlanta, Georgia; Kenya Medical Research Institute, Nairobi, Kenya;Nyando Integrated Child Health and Education (NICHE) Project, Kisumu, Kenya
School-based hygiene and water treatment programs increase student knowledge, improve hygiene, and decrease absenteeism, however health impact studies of these programs are lacking. We collected baseline information
from students in 42 schools in Kenya. We then instituted a curriculum on safe water and hand hygiene and installed water stations in half (“intervention schools”).
One year later, we implemented the intervention in remaining schools. Through biweekly student household visits and two annual surveys, we compared the effect of the intervention on hygiene practices and reported student illness. We saw improvement in proper handwashing techniques after the school program was introduced.
We observed a decrease in the median percentage of students with acute respiratory illness among those exposed to the program; no decrease in acute diarrhea was seen. Students in this school program exhibited sustained improvement in hygiene knowledge and a decreased risk of respiratory infections after the intervention.
Soil-Transmitted Helminth Infections and Correlated Risk Factors in Preschool and School-Aged Children in Rural Southwest China. PLoS ONE, Sept 2012.
Xiaobing Wang et al.
We conducted a survey of 1707 children in 141 impoverished rural areas of Guizhou and Sichuan Provinces in Southwest China. Kato-Katz smear testing of stool samples elucidated the prevalence of ascariasis, trichuriasis and hookworm infections in pre-school and school aged children. Demographic, hygiene, household and anthropometric data were collected to better understand risks for infection in this population. 21.2 percent of pre-school children and 22.9 percent of school aged children were infected with at least one of the three types of STH. In Guizhou, 33.9 percent of pre-school children were infected, as were 40.1 percent of school aged children. In Sichuan, these numbers were 9.7 percent and 6.6 percent, respectively.
Number of siblings, maternal education, consumption of uncooked meat, consumption of unboiled water, and livestock ownership all correlated significantly with STH infection. Through decomposition analysis, we determined that these correlates made up 26.7 percent of the difference in STH infection between the two provinces. Multivariate analysis showed that STH infection is associated with significantly lower weight-for-age and height-for-age zscores; moreover, older children infected with STHs lag further behind on the international growth scales than younger children.
