Water-Borne Pathogens With Relation To Gastroenteritis in Tubas District : An Epidemiological Study

Two hundred drinking — water samples were collected randomly from two storage systems (cisterns and roof storage tanks). The samples were collected during the summer season from March, l5 to June, 20/2000, from five villages (Tubas, Tammun, El-Fara, Aqqaba and Tayasir) in Tubas district. Both the average total coliform count and faecal coliform counts were used as indicators for water quality using the membrane filtration technique. Water samples that were positive for coliform were further cultured for the isolation of Salmonella, Shigella and E.c0li O157: H7. Both indicators gave average counts higher than that recommended as safe drinking — water by WHO. The average counts of total coliform were 2.056, 20.73, and 16.79 CFU/100ml water in municipality water, rain water, and spring water respectively. Based on the average count for both indicators, no significant variations were observed on the quality of drinking —- water in Tammun,Tayasir and 'Aqqaba villages, but there is significant variation on the quality of drinking-water between these villages (Tammun, Tayasir and Aqqaba) on one side and ( Tubas and El-Para') on the other side. The degree of contamination based on total coliform count in both rain water and spring water were similar and the majority were with first degree of contamination according to WHO classification, while the majority of municipality water samples were with zero degree of contamination (free of contamination). Based on thermotolerent coliform E.c0li with respect to the risk levels, both rain water and spring water were within no risk, low risk, and intermediate risk levels, according to WHO classification, while all municipality water samples were with no risk levels. A noticeable decrease in both indicators is clear up to a distance of 20m and above between cesspits and cisterns, with respect to total coliform count and faecal coliform counts. The households with history of animal raising, not cleaned cisterns, and no disinfectants were used in storage systems seem to have further effect on the contamination and risk levels compared to finding on households with no history of animal raising, cistern cleaning every year, and use of disinfectants. During the period from May, 26 to July, 21/2000, one hundred stool specimens were collected from patients with diarrhoea at four Public Medical Units located in Tubas, Tammun, and El-Fara villages. Prevalence rates of encountered parasites were as follows: Giardia lambia (12%), E.hist0lytica (16%), and H.nana (4%). The findings indicated very weak association between drinking water source and intestinal parasites.