Abstract
Background
“Green” construction approaches may place hospitals at risk for long-term contamination of potable water, presenting hazards for immunosuppressed patients. Remediation may be needed to manage these unanticipated consequences. An indolent, 11-year cluster of Sphingomonas koreensis infections at the NIH Clinical Center was traced to potable water. During the investigation, 4 sinks in 2 ICU rooms were found to have intractable contamination. Despite replacement of sink fixtures, faucet swabs and water continued to grow S. koreensis, and mean free chlorine residual (FCR) from the sinks was 0.27 mg/L (goal > 0.5). We undertook a major project to replace and reroute sections of pipes leading to the sinks (Figures 1 and 2).
Methods
Hot and cold water pipes were removed from the sinks to the supply pipes and replaced. Pipes were rerouted so that hot and cold water supplying the sinks returned in a loop to the domestic hot water heater to eliminate 10-meter drop-down sections of dead-leg pipe. Automatic faucets were replaced with manual faucets. Faucet biofilm was swabbed and cultured monthly for S. koreensis. Environmental samples were cultured on sheep blood agar for 5 days. Yellow colonies were subcultured and identified by MALDI-TOF MS (Bruker).
Results
Demolition of the wall behind the sinks revealed hot and cold water piping containing stagnant water. Water pooled in cold water pipe had heavy growth of S. koreensis; water from the hot water pipe could not be collected. Hot and cold water FCR for the sinks after piping changes averaged 0.74 and 1.07 mg/L, respectively, compared with 0.27 mg/L simultaneously from automated faucets in unmodified ICU rooms. Faucet cultures were negative for S. koreensis after replumbing, and have remained negative for >6 months.
Conclusion
New hospital construction strategies appear to increase potable water contamination risks; novel remediation approaches are needed. Replacing contaminated water pipes and rerouting pipes to minimize stagnation eradicated longstanding contamination of 2 ICU sinks. Although the experiment was conducted on a small scale, it demonstrates that plumbing flaws that jeopardize patient safety can be corrected through multidisciplinary collaboration and creative plumbing strategies.
Disclosures
All authors: No reported disclosures.
An exergy analysis for overall hidden losses of energy in solar water heater
