Bacteriologic potability of the drinking water in a diarrhea hyperendemic area in southwestern Saudi Arabia.

High prevalence of diarrhea was reported among people living in a semiurban community in Shebaa area in Southwestern Saudi Arabia. This was in comparison to prevalence in a nearby urban community in Abha, the capital city of The Southwestern Region of Saudi Arabia. Contamination of the desalinated water, commonly used for drinking, was one possible hypothesis for occurrence of this diarrhea problem. The objective of the present study was to test bacteriological potability of desalinated water in both Shebaa and Abha areas and to determine whether any contamination occurred during transportation from water distribution stations to houses or during storage in house reservoirs. Water samples were collected and analyzed by the Presumptive Coliform Test from a sample of water tankers transporting water and from tap water originating from house reservoirs in a sample of houses in the two areas. Source of drinking water was recorded for each of such houses. Of 117 water samples from 39 tankers transporting water, only one sample was positive bacteriologically and non-potable (potability = 99%). Whereas among 201 tap water samples from a random sample of houses, 26.4% showed contamination. Bacteriological non-potability was found in a significantly higher proportion of houses in Shebaa area (38.4%) than in Abha city (7.9%), (p<0.001). Also, desalinated water was used for drinking significantly more in Shebaa than in Abha (p<0.001). It is concluded that transportation of the desalinated water by water tankers has not significantly contributed to its contamination. Such contamination rather obviously occurred during storage in house reservoirs, and was possibly implicated, at least partly, in the increased prevalence of diarrhea in Shebaa.