Management of Microbiological Contamination of the Water Network of a Newly Built Hospital Pavilion

Abstract

The good installation, as well as commissioning plan, of a water network is a crucial step in reducing the risk of waterborne diseases. The aim of this study was to monitor the microbiological quality of water from a newly built pavilion before it commenced operation. Overall, 91 water samples were tested for coliforms, Escherichia coli, enterococci, Pseudomonas aeruginosa and Legionella at three different times: T0 (without any water treatment), T1 (after treatment with hydrogen peroxide and silver ions at initial concentration of 20 mg/L and after flushing of water for 20 min/day for seven successive days) and T2 (15 days later). Coliforms were detected in 47.3% of samples at T0, 36.3% at T1 and 4.4% at T2. E. coli was isolated in 4.4% of the samples only at T1, while enterococci appeared in 12.1% of the samples at T1 and in 2.2% at T2. P. aeruginosa was isolated in 50.5% of the samples at T0, 29.7% at T1 and 1.1% at T2. Legionella pneumophila serogroup 8 was isolated in 80.2% of the samples at T0, 36.3% at T1 and 2.2% at T2. Our results confirmed the need for a water safety plan in new hospital pavilions to prevent the risk of waterborne diseases.

Keywords: E. coli; Legionella; P. aeruginosa; coliforms; enterococci; hospital; legionellosis; new pavilion; water networks; waterborne diseases.

Figure 1

Box plot of the coliform load (CFU/100 mL) (A), enterococci load (CFU/100 mL) (B), P. aeruginosa load (CFU/250 mL) (C) and L. pneumophila load (CFU/L) (D), at T0, T1 and T2; CFU = colony forming units; ° = outlier values.