Browsing by Author "Legesse, Tesfaye"

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    Virological and Bacteriological Quality of Selected Drinking Water Samples Referred to Ethiopian Public Health Institiute
    (Addis Ababa University, 2016-10) Legesse, Tesfaye; Desta, Kassu (Assistant Professor)
    Background: Water Quality monitoring is assessed widely using different indicators. Since there is no universal indicator that has been identified yet, assessing water quality using bacterial and viral indicators that would provide a more complete picture of water quality. Objective: To assess the quality of drinking water using bacterial and cophages indicators. Methodology: A cross sectional prospective study was conducted on 218 drinking water samples of various sources collected from some regions of Ethiopia from February to June 2016 to determine coliphages by the help of CB390 E. coli host using plaque assay technique; most probable number for coliforms and pouring for hetrotrophic plate count at Ethiopian Public Health Institute. The data was analyzed using SPSS 20 statistical package. Results: Hetrophilic bacteria, total and thermotolerant coliforms, E. coli and coliphages were detected in 72.9 %, 51.8%, 38.5%, 23.9% and 2.3 % of total water samples respectively. HPC > 1.0x102 Cfu/ml were noted in 41 (18.8%) water samples and detections of total coliforms, thermotolerant coliforms and E. coli in 38 (17.4%), 24 (11.0%) and 10 (4.6%) samples respectively and no detection of phages in chlorinated waters. While, HPC > 1.0x102 Cfu/ml were observed in 100 (45.9%) water samples and detections of total and thermotolerant coliforms, E.coli and coliphages in 75 (34.4%), 60 (27.5%), 42 (19.3% ) and 5 (2.3%) samples respectively for the untreated waters. Rho values between total coliphages and other indicators, HPC, total coliforms, thermotolerant coliforms were 0.202, 0.232 and 0.269 respectively. Total heterophilic plate count, total coliforms, thermotolerant coliforms, E.coli and total coliphages were statistically differed by region; sources and treatment type (P value < 0.05). Coliphages were not detected in all waters except rivers. Conclusion: Majority of the waters, mainly untreated sources contained bacterial and viral indicators above the standard limits. This indicates that the sources are contaminated with environmental and fecal contaminants signifying poor quality of water and it is a potential threat for human health. Hence regular monitoring of water source using coliphages and other bacterial indicators should be a priority agenda by all stake holders. Keywords: Indicators, drinking water, water sources, coliforms, coliphage