Hospital Water Supply as a Potential Source of Opportunistic Pathogens

Abstract

In Egypt as well as in many other developing countries, there are no specific standards for hospital water. Even water is free from the traditional bacterial indicators, it may represent a source of health hazards especially for elderly, children and patients under dialysis due to the presence of opportunistic pathogenic bacteria. The study was carried out on the bacteriological water quality at the intakes as well as the end of water treatment train of two water treatment plants that supplying three hospitals located in Greater Cairo, Egypt with water that used for different purposes. Samples of the raw water supply for the two water treatment plants (Nile River water) showed ranges of 10²-10⁵ cfu mL^-1, 10²-10⁴ MPN 100 mL^-1, 10²-10⁴ MPN 100 mL^-1 and 10²-10³ MPN 100 mL^-1 for Heterotrophic Plate Count (HPC) bacteria, Total Coliforms (TC), Fecal Coliforms (FC) and Fecal Streptococci (FS), respectively. Treated water showed considerable reduction in HPC while the other bacterial indicators reached the undetectable level. The distribution system impact on treated water quality was limited to causing an increase in HPC bacteria. A study was carried out to determine the presence of Pseudomonas aeuginosa, Aeromonas spp. and Staphylococcus aureus in hospitals tap water, water reservoirs, as well as water for preparation of hemodialysis fluids. Although the post-chlorinated water in both water treatment plants was free from bacterial indicators, it still contaminated with the three studied opportunistic pathogenic bacteria. The detected opportunistic pathogens may be attributed to the distribution system condition and/or the presence of storage tanks. Hemodialysis water samples showed the higher percentage of P. aeruginosa isolates which represent a major source of health risk to patient’s attending dialysis process in hospitals and clinics. The presence of opportunistic bacteria in drinking water and dialysate with absence of coliform and low HPC suggested that the criteria for drinking water are usually not adequate for water used in hospitals. The purpose for which the water is to be used determines the criteria for water quality. Storage of water should be as hygienic as possible.