14 research outputs found
Health Impact Assessment of Solar Disinfection (SODIS) of Drinking Water in Three African Countries
The European Union (EU) under the Specific Programme, Integrating and Strengthening the European Research Area, Call Title: Specific Targeted Projects for African, Caribbean, Pacific Partner Countries, Call Identifier: FP6-2004-INCO-DEV-3, funded the project titled: Solar Disinfection of Drinking Water in Developing Countries or in Emergency Situation (SODISWATER), grant agreement number 013650. The project started in October 2006 and ended in March 2010.
The aim of SODISWATER was to demonstrate that Solar Disinfection (SODIS) of drinking water is an appropriate, effective and acceptable intervention against waterborne disease for vulnerable communities in developing countries without reliable access to safe water.
The scientific objectives for the overall project were to initialise in depth research in each of the following topics:
1. Health impact assessment studies in three African countries.
2. Microbiological studies to determine the response of the most important
untested waterborne pathogens to solar disinfection.
3. Enhancement techniques designed to improve the efficiency of inactivation (e.g. continuous flow systems, compound parabolic reactors).
4. Socio-psychological studies concerned with successful diffusions and behavioural change strategies for sustainable adoption of solar disinfection.
This thesis describes the rationale, methods and findings of the first scientific objective \u22Health impact assessments in three African countries.\u22 The author was responsible for the overall coordination of the three African studies based on the protocol of the health impact assessments she developed during the proposal development phase. The health impact assessments were undertaken in South Africa by the Council for Scientific and Industrial Research (CSIR), and two non-governmental organisations (NGOs), the Institute for Water and Sanitation Development (IWSD) in Zimbabwe and the International Community for the Relief of Starvation and Suffering (ICROSS) in Kenya.
The study design of the health impact assessments were undertaken by amultidisciplinary research team consisting of a software developer, a statistician and the author who is a trained microbiologist Standardisation of the procedures for the multi-country health impact assessments was made possible by the development of two manuals: 1) SODISWATER Field Manual (Appendix A) and 2) Diarrhoea1 Diaries Data Entry Manual (Appendix 6). The author provided the basis appropriate for inclusion of all relevant aspects for the development of the manuals and contributed to the design and contents of these manuals. The development of the manuals was undertaken in collaboration with a software developer who was also responsible for the development of the database and accompanying software used for managing and verifying the captured data. The software developer also assisted with programming the handheld computers that were used for capturing field data.
Field workers and field coordinators from South Africa as well as the field coordinators from Kenya and Zimbabwe attended a five day course developed and presented by the author. The course content was based on the procedures described in the manuals. To familiarise the attendees with the use of the electronic equipment, anthropometry equipment, water analysis method and interpretation of the results, practical sessions were conducted at the CSIR. The attendees were trained in the use of handheld computers, downloading information onto the database, use of the dedicated project computers and how to correct mistakes in the data when possible. A small pilot study, undertaken in the study area, provided the opportunity to apply the knowledge gained under real field conditions. The attendees were encouraged to use the manuals as guidance during execution of all procedures necessary to conduct the health impact assessments in the respective countries. Ethical issues were highlighted and advice given on how to approach and address potential study participants respectfully.
The author was responsible for the initial questionnaire development. These were refined in collaboration with the project teams from Kenya and Zimbabwe. The author also acquired the equipment and consumables for the respective studies.
The author personally co-ordinated the South African trial and was closely involved in all the activities, including overseeing the field workers, data collection, data capturing, data correction and initial analysis. The study teams and study areas in Kenya and Zimbabwe were visited in person by the author when specific problems had to be resolved. General problems experienced by field co-ordinators in Kenya and Zimbabwe were resolved by using electronic mail and the telephone.
Basic statistical analyses were performed by the author. However the bulk of the subgroup analyses were performed by a fully trained statistician. The author endeavoured to understand the basis of sub-analyses and the interpretation thereof.
The author compiled the entire thesis
Evaluation of an Inexpensive Growth Medium for Direct Detection of Escherichia coli in Temperate and Sub-Tropical Waters
The cost and complexity of traditional methods for the detection of faecal indicator bacteria,
including E. coli, hinder widespread monitoring of drinking water quality, especially in lowincome
countries and outside controlled laboratory settings. In these settings the problem is
exacerbated by the lack of inexpensive media for the detection of E. coli in drinking water.
We developed a new low-cost growth medium, aquatest (AT), and validated its use for the
direct detection of E. coli in temperate and sub-tropical drinking waters using IDEXX QuantiTray1.
AT was compared with IDEXX Colilert-181 and either EC-MUG or MLSB for detecting
low levels of E. coli from water samples from temperate (n = 140; Bristol, UK) and subtropical
regions (n = 50, Pretoria/Tshwane, South Africa). Confirmatory testing (n = 418 and
588, respectively) and the comparison of quantitative results were used to assess performance.
Sensitivity of AT was higher than Colilert-181 for water samples in the UK [98.0%
vs. 86.9%; p<0.0001] and South Africa [99.5% vs. 93.2%; p = 0.0030]. There was no significant
difference in specificity, which was high for both media (>95% in both settings). Quantitative
results were comparable and within expected limits. AT is reliable and accurate for
the detection of E. coli in temperate and subtropical drinking water. The composition of the
new medium is reported herein and can be used freely
Evaluation of an Inexpensive Growth Medium for Direct Detection of Escherichia coli in Temperate and Sub-Tropical Waters
The cost and complexity of traditional methods for the detection of faecal indicator bacteria, including E. coli, hinder widespread monitoring of drinking water quality, especially in low-income countries and outside controlled laboratory settings. In these settings the problem is exacerbated by the lack of inexpensive media for the detection of E. coli in drinking water. We developed a new low-cost growth medium, aquatest (AT), and validated its use for the direct detection of E. coli in temperate and sub-tropical drinking waters using IDEXX Quanti-Tray®. AT was compared with IDEXX Colilert-18® and either EC-MUG or MLSB for detecting low levels of E. coli from water samples from temperate (n = 140; Bristol, UK) and subtropical regions (n = 50, Pretoria/Tshwane, South Africa). Confirmatory testing (n = 418 and 588, respectively) and the comparison of quantitative results were used to assess performance. Sensitivity of AT was higher than Colilert-18® for water samples in the UK [98.0% vs. 86.9%; p95% in both settings). Quantitative results were comparable and within expected limits. AT is reliable and accurate for the detection of E. coli in temperate and subtropical drinking water. The composition of the new medium is reported herein and can be used freely
Development of novel seminested polymerase chain reaction assays for detecting toxigenic Vibrio cholerae and Shigella spp. in water
Please read the abstract in the section, 00front, of this documentDissertation (MSc)--University of Pretoria, 2001.Microbiology and Plant PathologyMScunrestricte
Use of ceramic water filtration in the prevention of diarrheal disease: a randomized controlled trial in rural South Africa and Zimbabwe
To determine the effectiveness of ceramic filters in reducing diarrhea, we conducted a randomized controlled trial in Zimbabwe and South Africa, in which 61 of 115 households received ceramic filters. Incidence of non-bloody and bloody diarrhea was recorded daily over 6 months using pictorial diaries for children 24–36 months of age. Poisson regression was used to compare incidence rates in intervention and control households. Adjusted for source quality, intervention household drinking water showed reduced Escherichia coli counts (relative risk, 0.67; 95% CI, 0.50–0.89). Zero E. coli were obtained for drinking water in 56.9% of intervention households. The incidence rate ratio for bloody diarrhea was 0.20 (95% CI, 0.09–0.43; P < 0.001) and for non-bloody diarrhea was 0.17 (95% CI, 0.08–0.38; P < 0.001), indicating much lower diarrhea incidence among filter users. The results suggest that ceramic filters are effective in reducing diarrheal disease incidence. <br/
Child dysentery in the Limpopo Valley: a cohort study of water, sanitation and hygiene risk factors
The objective of this cohort study was to assess risk factors for child dysentery and watery diarrhoea. The study participants consisted of 254 children aged 12–24 months in rural SouthAfrica and Zimbabwe in households where drinking water was collected from communal sources. The main outcome measure was the most severe diarrhoea episode: dysentery, watery diarrhoea or none. For dysentery, drinking water from sources other than standpipes had a relative risk ratio of 3.8 (95% CI 1.5–9.8). Poor source water quality, as indicated by Escherichia coli counts of 10 or more cfu 100 ml21, increased risk by 2.9 (1.5–5.7). There were no other significant risk factors for dysentery and none for watery diarrhoea. In this study, endemic dysentery is associated only with faecal contamination of source water. Sources other than standpipes, including improved groundwater, are of greater risk. Remediation of water quality by treatment at source or in the household will be required to achieve access to safe drinking water in accordance with the 7th Millennium Development Goal
Child dysentery in the Limpopo Valley: a cohort study of water, sanitation and hygiene risk factors
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Evaluation of an Inexpensive Growth Medium for Direct Detection of Escherichia coli in Temperate and Sub-Tropical Waters.
The cost and complexity of traditional methods for the detection of faecal indicator bacteria, including E. coli, hinder widespread monitoring of drinking water quality, especially in low-income countries and outside controlled laboratory settings. In these settings the problem is exacerbated by the lack of inexpensive media for the detection of E. coli in drinking water. We developed a new low-cost growth medium, aquatest (AT), and validated its use for the direct detection of E. coli in temperate and sub-tropical drinking waters using IDEXX Quanti-Tray®. AT was compared with IDEXX Colilert-18® and either EC-MUG or MLSB for detecting low levels of E. coli from water samples from temperate (n = 140; Bristol, UK) and subtropical regions (n = 50, Pretoria/Tshwane, South Africa). Confirmatory testing (n = 418 and 588, respectively) and the comparison of quantitative results were used to assess performance. Sensitivity of AT was higher than Colilert-18® for water samples in the UK [98.0% vs. 86.9%; p<0.0001] and South Africa [99.5% vs. 93.2%; p = 0.0030]. There was no significant difference in specificity, which was high for both media (>95% in both settings). Quantitative results were comparable and within expected limits. AT is reliable and accurate for the detection of E. coli in temperate and subtropical drinking water. The composition of the new medium is reported herein and can be used freely
Scatter plots of aquatest <i>E</i>. <i>coli</i> estimates versus Colilert-18<sup>®</sup>, EC-MUG and MLSB in temperate water samples.
<p>Scatter plots of aquatest <i>E</i>. <i>coli</i> estimates versus Colilert-18<sup>®</sup>, EC-MUG and MLSB in temperate water samples.</p
aquatest <i>E</i>. <i>coli</i> estimates versus Colilert-18<sup>®</sup> (A) scatter plot and (B) difference versus mean in sub-tropical water samples.
<p>aquatest <i>E</i>. <i>coli</i> estimates versus Colilert-18<sup>®</sup> (A) scatter plot and (B) difference versus mean in sub-tropical water samples.</p