A randomized trial to evaluate the risk of gastrointestinal disease due to consumption of drinking water meeting current microbiological standards (original) (raw)
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International Journal of Environmental Health Research, 1997
The objective of this study was to assess if drinking water meeting currently accepted microbiological standards is the source of gastrointestinal illnesses and to attempt to identify the source(s) of these illnesses. A randomized prospective study was conducted over a period of 16 months (September 1993 ±December 1994 in a middle class suburban community served by a single water filtration plant. A representative sample of 1400 families were selected and randomly allocated in four groups of 350, to the following regimens: (1) tap water; (2) tap water from a continuously purged tap; (3) bottled plant water; (4) purified bottled water (tap water treated by reverse osmosis or spring water). The water treatment plant produced wather that met or exceeded current North American regulations for drinking water quality. The distribution system was found to be in compliance for both coliforms and chlorine. Using the purified water group as the baseline, the excess of gastrointestinal illness associated with tap water was 14% in the tap group and 19% in the tap-valve group. Children 2 ±5 years old were the most affected with an excess of 17% in the tap group and 40% in the tap-valve group. Mottled plant water was not the source of any increase in the incidence of gastrointestinal illnesses, even if it contained very high levels of heterotrophic bacteria after two weeks. The data collected suggest that 14 ±40% of the gastrointestinal illnesses are attributable to tap water meeting current standards and that the water distribution system appears to be partly responsible for these illnesses.
American Journal of Public Health, 1987
In a prospective follow-up study conducted in 52 French alpine villages, one weekly water sample was taken in each village provided with untreated ground water and analyzed as to the presence of four indicator bacteria: total plate count, total coliforms, thermotolerant (fecal) coliforms, and fecal streptococci. Cases of acute gastro-intestinal disease (AGID) occurring among 29,272 inhabitants were reported through physicians, pharmacists, and Address reprint requests to
=High enteric bacterial contamination of drinking water in
Background: The high prevalence of diarrheal disease among children and infants can be traced due to the use of unsafe water and unhygienic practices. The overall concept adopted for microbiological quality is that no water intended for human consumption shall contain Escherichia coli per 100 ml sample. Objective: The aim of this study was to assess household water handling and hygienic practices and to determine bacteriological quality of drinking water from different sources in Jigjiga city. Methods: A cross-sectional study was conducted to assess bacteriological quality of drinking water in Jigjiga city from May-August, 2013. Both simple random and convenient sampling techniques were applied to select 238 households to assess water handling and hygienic practices, and 125 water samples to assess bacteriological quality of drinking water respectively. The water samples were collected from household water container, pipeline, water reservoir, 'Beyollie', and main sources. Easily isolated bacteria called coliforms were used as indicator organisms of human and other animals' fecal contamination status of drinking water. Data were summarized using descriptive and analytical statistics. Chi-square (χ2) and logistic regression tests were used and p<0.05 was considered as cut off value for statistical significance. Results: Overall, 71.2%(n=89) of water samples were contaminated by one or more bacterial species of E.coli, Shigella Sp, Salmonella Sp, and Vibrio sp. Particularly, 65(52%), 10(8%), 9(7.2%), and 8(6.4%) were contaminated by E.coli, Shigella sp, Salmonella sp, and Vibrio sp, respectively. On the other hand, 20% of the households and pipeline water samples had a fecal coliform count of 150 and above. Placement of water drinking utensils had a statistically significant association with illiterate education (p=0.01, AOR=5.47, 95% CI: (1.31, 22.78)) and male household head (p=0.02, AOR=2.11, 95% CI: (1.10, 4.05)).
Illness in a community associated with an episode of water contamination with sewage
Epidemiology and Infection, 1995
Following an episode of water contamination with sewage in a rural Irish town, a community-wide survey of gastrointestinal-associated illness and health service utilization was conducted. Random sampling of households yielded residents who were surveyed using a self-administered questionnaire. Of 560 respondents from 167 (84%) households, equal proportions lived in areas known to have been exposed and unexposed to the contaminated water, although 65% of subjects reported using contaminated water. Sixty-one percent of subjects met the case definition. The most common symptoms among cases were abdominal cramps (80%), diarhoea (75%), appetite loss (69%), nausea (68%) and tiredness (66%).
The American journal of tropical medicine and hygiene, 2007
We evaluated enteric infection serology as an alternative outcome measure to diarrhea prevalence in a randomized controlled trial of household-based drinking water treatment; 492 households were randomly assigned to 5 household-based water treatment interventions or control. Individuals were followed weekly over 52 weeks to measure diarrhea prevalence. Study subjects of age <or= 6 months and < 24 months had blood drawn at entry and exit from the study or age cohort. Serologic assays for Cryptosporidium parvum, Giardia intestinalis, enterotoxigenic Escherichia coli (ETEC), and Norovirus were done. Of 343 subjects eligible for the study, the proportions of subjects experiencing serologic responses were 56% for Norovirus, 24% for C. parvum, 10% for ETEC, and 16% for G. intestinalis. Serologic response was associated with increased diarrhea prevalence only for G. intestinalis (P = 0.0134). Serologic response to the antigens tested for G. intestinalis but not for Norovirus, C. parv...
The Professional Medical Journal
INTRODUCTION Fresh water is a source of transmission of pathogens like viruses, bacteria and protozoa. The assessment of drinking water for fecal contaminants is important information for health authorities. The degree of fecal contamination in rivers, lakes, reservoirs and groundwater aquifers 1,2 is variable. Instead of global efforts and latest techniques water born diseases are still a 3 challenge. Many studies have been conducted for the assessment of contamination of drinking water and prevention of the water borne diseases world 4,5 wide. In Pakistan, common people use subjective quality criteria like brackish, foul smelling, bad tasting, and turbid or colored water to determine that it is not suitable for drinking. The agencies responsible for monitoring of water quality perform periodic checks of the basic water parameters against certain recommended standards. In order to ensure that consumers throughout the country are receiving quality water, research-based standards and guidelines for quality drinking water 6 must be available to monitoring agencies. Bacteriological contamination of drinking water has been reported to be one of the most serious
Bacterial Indicators of Risk of Disease from Drinking Water
Microbial pathogens or contaminants in drinking water have been implicated in various gastrointestinal illnesses that have occurred in different parts of the country. Waterborne pathogens cause a whole range of diarrheal diseases. The occurrence of such outbreaks alerted people to the hazards of drinking contaminated water and prompted investigations into ways to prevent the occurrence of waterborne illnesses. Public health authorities still have not achieved success in controlling the most common waterborne diseases in Pakistan and other developing countries. Bacteriological analysis of 358 water samples consisting of 225 bottled water, and 133 ground, river and well water being used for drinking purpose in different parts of country was done according to World Health Organization (WHO) Guidelines by membrane filtration techniques and Multiple Tube Method. Results A two year long study showed that most of Pakistanis are still using contaminated water which is not safe for human health. Almost 90% of ground water and well water samples were found to be contaminated with coli forms and fecal coli forms. Whereas 37% of bottle water samples were showed the presence of coli forms and fecal coli forms. Overall 67% of total water samples were found to be contaminated with coli forms and fecal coli forms.