Engineering waterborne Pseudomonas aeruginosa out of a critical care unit

Objective: To describe engineering and holistic interventions on water outlets contaminated with Pseudomonas aeruginosa and the observed impact on clinical P. aeruginosa patient isolates in a large Intensive Care Unit (ICU). Design: Descriptive study. Setting: Queen Elizabeth Hospital Birmingham (QEHB), part of University Hospitals Birmingham (UHB) NHS Foundation Trust is a tertiary referral teaching hospital in Birmingham, UK and provides clinical services to nearly 1 million patients every year. Methods: Breakpoint models were used to detect any significant changes in the cumulative yearly rates of clinical P. aeruginosa patient isolates from August 2013-December 2016 across QEHB. Results: Water sampling undertaken on the ICU indicated 30% of the outlets were positive for P. aeruginosa at any one time. Molecular typing of patient and water isolates via Pulsed Field Gel Electrophoresis suggested there was a 30% transmission rate of P. aeruginosa from the water to patients on the ICU. From, February 2014, QEHB implemented engineering interventions, consisting of new tap outlets and PALL point-of-use filters; as well as holistic measures, from February 2016 including a revised tap cleaning method and appropriate disposal of patient waste water. Breakpoint models indicated the engineering and holistic interventions resulted in a significant (p < 0.001)50% reduction in the number of P. aeruginosa clinical patient isolates over a year. Conclusion: Here we demonstrate that the role of waterborne transmission of P. aeruginosa in an ICU cannot be overlooked. We suggest both holistic and environmental factors are important in reducing transmission. (C) 2017 Elsevier GmbH. All rights reserved.