Evaluation of Factors Predisposing to Bacterial Contamination of Drinking Water Sources: A study at Kitale Municipality, Kenya

Abstract

Faecal contamination of drinking water was assessed using various water sources in households in four peri-urban areas of Kitale Municipality, Kenya. We measured counts of faecal and faecal thermotolerant coliforms in Municipal treated water, well, spring and borehole water within 115 selected households. Borehole recorded no faecal contamination but (28%) of treated tap water, 100% of well and river water had fecal contamination. Bacteriological analysis involved the use of Membrane filter technique to isolate total coliforms and faecal thermo-tolerant coliforms contaminants on Endo agar and MacConkey agar respectively. These were further identified by subculture, microscopy and biochemical tests. We isolated mainly faecal coliforms and faecal thermotolerant coliforms which included Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Proteus species, Salmonella species, Shigella, Citrobacter , Enterobacter species and Streptococcus faecalis. Demographic data was obtained by use of self administered questionnaires on residents and water supply operators. Some of the risk factors found to have significant influence on the quality of drinking water included depth of well / borehole, distance from possible contaminating source, poor housing and sanitation , delay in repair of burst pipes and absence of protective cover in wells, type of water source and boreholes.

Key words: Faecal coliforms, predisposing factors, culture, biochemical tests.