Virological and bacteriological quality of drinking water in Ethiopia

Abstract

Background: Since unsafe water is responsible for serious illness, deaths due to highest burdens of diseases and greatest economic failure, monitoring the quality of water is essential. Water Quality monitoring is assessed widely using different indicators. Bacterial and viral indicators provide more complete picture of water quality. Virological quality of water hasn’t been assessed in most countries including Ethiopia. The use of E. coli CB390 minimizes resource and time to perform the tests in simultaneous detection of somatic and male-specific coliphages. Methods & Materials: A cross sectional study was conducted on 218 drinking waters samples collected from various regions of Ethiopia from February to June 2016 to assess water quality using coliphages by the help of CB390 E. coli host, plaque assay; Multiple tube fermentation method for coliforms and pour plate technique for counting heterotrophic bacteria at Ethiopian Public Health Institute. The data were analyzed using SPSS 20. Results: Heterotrophic bacteria, total and thermotolerant coliforms, E. coli and phages were detected in 72.9%, 51.8%, 38.5%, 23.9% and 2.3% of the total samples respectively. Heterotrophic plate count greater than 100 CFU/ml were noted in 41 (18.8%) samples and detections of total and 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, Heterotrophic plate count greater than 100 CFU/mL were observed in 100 (45.9%) 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 untreated waters. Conclusion: Majority of the waters contained indicators above standard limits. This indicates that the sources are contaminated with environmental and fecal contaminants signifying poor quality and it is a potential threat to human and animals health. Hence regular water monitoring using various indicators should be a priority agenda by all stake holders.