Preventive Efficacy and Cost-effectiveness of Point-of-Use Water Filtration in a Sub-acute Care Unit

Background: Infections with Pseudomonas aeruginosa and other waterborne pathogens (WBP) are major contributors to serious morbidity and mortality in hospitals.  Patients in sub-acute care, including individuals on ventilators are at particularly high risk of healthcare-associated colonization and infection, especially ventilator-associated pneumonia (VAP). 

Objective: We sought to determine whether point-of-use (POU) water filtration might result in decreased risk of infection in the sub-acute care unit (SACU) of a 208-bed medical center.

Methods: Unfiltered and filtered water was sampled from taps in the SACU, and cultured at a reference laboratory.  POU bacterial-retentive filters (0.2 µm) were installed on sinks, showers and ice machines throughout the unit, and replaced every 14 days.  Infection rates were tracked over a five-month period, and compared with rates for a baseline control period.

Results: Six of 21 unfiltered water samples grew WBP, including P. aeruginosa; whereas, 0 of 42 filtered samples were positive for WBP.  Rates of VAP, positive cultures, and upper respiratory colonization with Pseudomonas were all significantly reduced with POU filtration.  In addition, a net cost saving of $231,036 was realized for the SACU during the study period. Conclusions: POU water filtration may significantly and cost-effectively reduce colonization and infection rates with WBP, including VAP in a sub-acute care unit.