All coliforms are not created equal : a comparison of the effects of water source and in-house water contamination on infantile diarrheal disease

Providing good quality water through hand pumps or water taps is not a guarantee that a family is drinking uncontaminated water. Many opportunities occur for contamination of drinking water during storage in the home. Studies have been performed on the type and quantity of contaminating organisms both in the water source and in the household storage containers, but the results were not always conclusive. This study was compiled from data from the Cebu Longitudinal Health and Nutrition Survey in Cebu, Philippines. Water was sampled at the home, and at the source. Water collection and storage practices were documented. Faecal coliforms were used as the indicator species. The study followed the occurrence of diarrhoeal disease in children as a result of contaminated water consumption. Little evidence was found that in-house contamination significantly increases the risk of diarrhoeal disease. One argument is that the children of the family develop immunity to the faecal pathogens of family members, while contamination from water sources contain "external" faecal pathogens. It was suggested that water source contamination is epidemiologically far more important than in-house contamination, and that there was no reason to delay improvements in water quality in the source because of possible in-house contamination.