Household Water Treatment: Chlorination – The Safe Water System

April 26, 2012 · 0 comments

Household Water Treatment: Chlorination – The Safe Water System, 2011. CDC.

The Safe Water System (SWS) was developed in the 1990’s in response to epidemic cholera in South America by the Centers for Disease Control and Prevention (CDC) and the Pan American Health Organization (PAHO).   The treatment method for the SWS is point-of-use chlorination  by  consumers with a locally-manufactured dilute sodium hypochlorite (chlorine bleach) solution.   The SWS also incorporates emphasis on safe storage of treated water  and behavior change communications to  improve water  and food handling, sanitation,  and hygiene practices in  the  home and in the community.    To  use the chlorination method, families add one full bottle cap of the sodium hypochlorite solution to clear water (or 2 caps to turbid water) in a standard sized container,  agitate, and wait 30 minutes before drinking.

Household Water Treatment: Flocculant/Disinfectant Powder

April 26, 2012 · 0 comments

Household Water Treatment: Flocculant/Disinfectant Powder, 2011. CDC.

The Procter & Gamble Company developed PUR Purifier of Water™ in conjunction with the Centers for Disease Control and Prevention.  PUR sachets are now centrally produced in Pakistan, and sold to nongovernmental organizations (NGOs) worldwide at a cost of 3.5 US cents per sachet.  The PUR product is a small sachet containing powdered ferric sulfate (a flocculant) and calcium hypochlorite (a disinfectant).  PUR was designed to reverse-engineer a water treatment plant, incorporating the multiple barrier processes of removal of particles and disinfection. To treat water with PUR, users open the sachet, add the contents to an open bucket containing 10 liters of water, stir for 5 minutes, let the solids settle to the bottom of the bucket, strain the water through a cotton cloth into a second container, and wait 20 minutes for the hypochlorite to inactivate the microorganisms.

Household Water Treatment: Solar Disinfection

April 26, 2012 · 0 comments

Household Water Treatment: Solar Disinfection, 2011. CDC.

Solar disinfection (SODIS) was developed in the 1980’s to inexpensively disinfect water used for oral rehydration solutions.  In 1991, the Swiss Federal Institute for Environmental Science and Technology began to investigate and implement SODIS as an  household water treatment option to prevent diarrhea in developing countries.  Users of SODIS fill 0.3-2.0 liter plastic soda bottles with low-turbidity water, shake them to oxygenate, and place the bottles on a roof or rack for 6 hours (if sunny) or 2 days (if cloudy).  The combined effects of UV-induced DNA alteration, thermal inactivation, and photo-oxidative destruction inactivate disease-causing organisms.

Household Water Treatment: Ceramic Filtration

April 26, 2012 · 0 comments

Household Water Treatment: Ceramic Filtration, 2011. CDC.

Locally manufactured ceramic filters have traditionally been used throughout the world to treat household water.  Currently, the most widely implemented ceramic filter  is the Potters for Peace design. The filter is flowerpot  shaped, holds about 8-10 liters of water, and sits inside a plastic or ceramic receptacle.  To use the ceramic filters, families fill the top receptacle or the ceramic filter itself with water, which flows through the ceramic filter or filters into a storage receptacle.  The treated water is then accessed via a spigot embedded within the water storage receptacle.  The filters are produced locally at ceramics facilities, and then impregnated with colloidal silver to ensure complete removal of bacteria in treated water and to prevent growth of bacteria within the filter itself.  Numerous other locally-made and commercial ceramic filters are widely available in developed and developing countries.

Household Water Treatment: Slow Sand Filtration

April 26, 2012 · 1 comment

Household Water Treatment: Slow Sand Filtration, 2011. CDC.

A slow sand filter is a sand filter adapted for household use. Please note that although commonly referred to as the BioSand Filter, the BioSand Filter terminology is trademarked to one particular design, and this fact sheet encompasses all slow sand filters. The version most widely implemented consists of layers of sand and gravel in a concrete or plastic container approximately 0.9 meters tall and 0.3 meters square. The water level is maintained to 5-6 cm above the sand layer by setting the height of the outlet pipe. This shallow water layer allows a bioactive layer to grow on top of the sand, which contributes to the reduction of disease-causing organisms. A diffuser plate is used to prevent disruption of the biolayer when water is added. To use the filter, users simply pour water into the top, and collect finished water out of the outlet pipe into a bucket. Over time, especially if source water is turbid, the flow rate can decrease. Users can maintain flow rate by cleaning the filter through agitating the top level of sand, or by pre-treating turbid water before filtration.

The Safe Water System: Safe Storage of Drinking Water

April 26, 2012 · 0 comments

The Safe Water System: Safe Storage of Drinking Water, 2011. CDC.

Safe storage options fall into three general categories: 1) existing water storage containers in the home; 2) water storage containers used in the community and modified by an intervention program; or, 3) commercial safe storage containers purchased by the program and distributed to users. To determine the appropriate safe storage container for a program, first identify containers currently used for water collection, transport, and storage in the community, as these existing containers might already be safe, or could easily be modified to be safe storage containers. Programs are also encouraged to review the options for safe water storage containers presented herein to determine which ones may be most appropriate. For more information, contact safewater@cdc.gov. Care should be taken to avoid using any container previously used for transport of toxic materials (such as pesticides or petroleum products) as a drinking water storage container. Lastly, locally-appropriate cleaning mechanisms – such as use of soap and brushes, or chlorine solution, or an abrasive – should be developed and recommended to clean the container on a regular basis.

An anthropological perspective on water and women’s psychosocial distress in Ethiopia

April 26, 2012 · 0 comments

Social Science & Medicine, 19 April 2012

Water insecurity in 3 dimensions: An anthropological perspective on water and women’s psychosocial distress in Ethiopia

Edward G.J. Stevensona, , , Leslie E. Greeneb, Kenneth C. Maesc, Argaw Ambelud, Yihenew Alemu Tesfayee, Richard Rheingansf, Craig Hadleyg

a Hubert Department of Global Health, Rollins School of Public Health, Emory University
b Center for Global Safe Water, Rollins School of Public Health, Emory University
c Population Studies and Training Center, Brown University
d Department of Environmental Health Sciences and Technology, Jimma University, Ethiopia
e Center for National Health Development in Ethiopia
f Department of Environmental and Global Health, University of Florida
g Department of Anthropology, Emory University

Water insecurity is a primary underlying determinant of global health disparities. While public health research on water insecurity has focused mainly on two dimensions, water access and adequacy, an anthropological perspective highlights the cultural or lifestyle dimension of water insecurity, and its implications for access / adequacy and for the phenomenology of water insecurity. Recent work in Bolivia has shown that scores on a water insecurity scale derived from ethnographic observations are associated with emotional distress. We extend this line of research by assessing the utility of a locally developed water insecurity scale, compared with standard measures of water access and adequacy, in predicting women’s psychosocial distress in Ethiopia.

In 2009-2010 we conducted two phases of research. Phase I was mainly qualitative and designed to identify locally relevant experiences of water insecurity, and Phase II used a quantitative survey to test the association between women’s reported water insecurity and the Falk Self-Reporting Questionnaire (SRQ-F), a measure of psychosocial distress. In multiple regression models controlling for food insecurity and reported quantity of water used, women’s water insecurity scores were significantly associated with psychosocial distress. Including controls for time required to collect water and whether water sources were protected did not further predict psychosocial distress. This approach highlights the social dimension of water insecurity, and may be useful for informing and evaluating interventions to improve water supplies.

Pattern of Maternal Knowledge and Its Implications for Diarrhoea Control in Southern Malawi

April 24, 2012 · 0 comments

Int. J. Environ. Res. Public Health March 2012, 9(3), 955-969

Pattern of Maternal Knowledge and Its Implications for Diarrhoea Control in Southern Malawi: Multilevel Thresholds of Change Analysis

Salule Joseph Masangwi, et al

A survey was conducted in Southern Malawi to examine the pattern of mothers’ knowledge on diarrhoea. Diarrhoea morbidity in the district is estimated at 24.4%, statistically higher than the national average at 17%. Using hierarchically built data from a survey, a multilevel threshold of change analysis was used to determine predictors of knowledge about diarrhoeal aetiology, clinical features, and prevention. The results show a strong hierarchical structured pattern in overall maternal knowledge revealing differences between communities.

Responsible mothers with primary or secondary school education were more likely to give more correct answers on diarrhoea knowledge than those without any formal education. Responsible mothers from communities without a health surveillance assistant were less likely to give more correct answers. The results show that differences in diarrhoeal knowledge do exist between communities and demonstrate that basic formal education is important in responsible mother’s understanding of diseases. The results also reveal the positive impact health surveillance assistants have in rural communities.

The Manufacture of Bio-Sand Water Filters in Rural Tanzania

April 24, 2012 · 2 comments

Diversity and Antibiograms of Bacterial Organisms Isolated from Household Drinking-water Samples

April 24, 2012 · 0 comments

Diversity and Antibiograms of Bacterial Organisms Isolated from Household Drinking-water Samples Consumed by HIV-positive Individuals in Rural Settings, South Africa, Jnl Health Pop Nut, Jan 2012.

A. Samie, et al.

Diarrhoea is a hallmark of HIV infections in developing countries, and many diarrhoea-causing agents are often transmitted through water. The objective of the study was to determine the diversity and antibiotic susceptibility profiles of bacterial organisms isolated from samples of household drinking-water consumed by HIV-infected and AIDS patients. In the present study, household water stored for use by HIV-positive patients was tested for microbial quality, and isolated bacterial organisms were analyzed for their antibiotic susceptibility profiles against 25 different antibiotics.

The microbial quality of water was generally poor, and about 58% of water samples (n=270) were contaminated with faecal coliforms, with counts varying from 2 colony-forming unit (CFU)/100 mL to 2.4×104 CFU/100 mL. Values of total coliform counts ranged from 17 CFU/100 mL to 7.9×105/100 mL. In total, 37 different bacterial species were isolated, and the major isolates included Acinetobacter lwoffii (7.5%), Enterobacter cloacae (7.5%), Shigella spp. (14.2%), Yersinia enterocolitica (6.7%), and Pseudomonas spp. (16.3%). No Vibrio cholerae could be isolated; however, V. fluvialis was isolated from three water samples.

The isolated organisms were highly resistant to cefazolin (83.5%), cefoxitin (69.2%), ampicillin (66.4%), and cefuroxime (66.2%). Intermediate resistance was observed against gentamicin (10.6%), cefepime (13.4%), ceftriaxone (27.6%), and cefotaxime (29.9%). Levofloxacin (0.7%), ceftazidime (2.2%), meropenem (3%), and ciprofloxacin (3.7%) were the most active antibiotics against all the microorganisms, with all recording less than 5% resistance. Multiple drug resistance was very common, and 78% of the organisms were resistant to three or more antibiotics.

Education on treatment of household water is advised for HIV-positive patients, and measures should be taken to improve point-of-use water treatment as immunosuppressed individuals would be more susceptible to opportunistic infections.

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