770 Contamination and Remediation of Hospital Water Systems Following Hurricane Ike

Sunday, March 21, 2010
Grand Hall (Hyatt Regency Atlanta)
Carmen Tichindelean, MD , Munson Medical Center, Traverse City, MI
Angela Hewlett, MD, MS , University of Nebraska Medical Center, Omaha, NE
Pamela Falk, MPH , University of Texas Medical Branch, Galveston, TX
C. Glen Mayhall, MD , University of Texas Medical Branch, Galveston, TX
Background:   The University of Texas Medical Branch, located in Galveston, Texas was directly impacted by Hurricane Ike in September 2008 and suffered serious damage including flooding of the entire hospital complex.  As a consequence, water service from the hospital water systems as well as the Galveston city water systems were disrupted, resulting in stagnant water conditions.  Concerns about contamination of the hospital water were immediate.  This study was initiated to determine the extent of contamination present as well as to investigate and describe courses of remediation.
Objective:   To assess for the presence of pathogenic organisms in the hospital water systems following a disaster, and to describe the methods of remediation used in an attempt to eradicate these pathogens.
Methods:    Water samples were collected to evaluate for the presence of bacteria (including Legionella sp.), acid-fast bacilli and fungal pathogens before and after remediation attempts.  Samples were obtained from multiple sources in patient care areas of the hospital complex.  Three core clinical buildings were initially selected for investigation.  Cultures were processed using routine methods.
Results:   Nontuberculous mycobacteria were isolated in 82 of 102 (80.4%) of water cultures taken prior to remediation attempts.  Legionella was isolated from 38 of 87 (43.7%) of pre-remediation water cultures.  Selected samples were confirmed as Legionella pneumophila, serogroup 1.  Other pathogenic organisms were also isolated, including Pseudomonas aeruginosa (7.8% of water samples) and Stenotrophomonas sp. (4.4% of water samples).  Fungal cultures were not revealing.  Remediation was attempted in 3 core clinical buildings using a chlorine dioxide flush.  Water samples obtained following the chlorine dioxide flush showed a significant reduction in the amount of positive cultures for Legionella in 2 of the 3 buildings. There was no reduction in the amount of nontuberculous mycobacteria in the water samples following the chlorine dioxide flush.  Thermal eradication (heat and flush) was performed in the building that did not respond to the chlorine dioxide flush, which resulted in a short-term reduction in the amount of Legionella present.  Intermittent copper-silver ionization was initiated and is currently in progress.
Conclusions:   Disruption in hospital water systems and subsequent contamination of these systems is a possible consequence of natural disasters.  Several options for remediation of water systems exist and should be considered in order to reduce the extent of contamination present.