Hospital-acquired Legionella pneumonia outbreak at an academic medical center: Lessons learned.

Autor: Kessler MA; Department of Medicine, University of Wisconsin-Madison, Madison, WI. Electronic address: kessler2@wisc.edu., Osman F; Department of Medicine, University of Wisconsin-Madison, Madison, WI., Marx J Jr; Department of Infection Control, University of Wisconsin Hospital, Madison, WI., Pop-Vicas A; Department of Medicine, University of Wisconsin-Madison, Madison, WI; Department of Infection Control, University of Wisconsin Hospital, Madison, WI., Safdar N; Department of Medicine, University of Wisconsin-Madison, Madison, WI; Department of Infection Control, University of Wisconsin Hospital, Madison, WI; Department of Research and Development, William S. Middleton Memorial Veterans Hospital, University of Wisconsin-Madison, Madison, WI.
Jazyk: angličtina
Zdroj: American journal of infection control [Am J Infect Control] 2021 Aug; Vol. 49 (8), pp. 1014-1020. Date of Electronic Publication: 2021 Feb 22.
DOI: 10.1016/j.ajic.2021.02.013
Abstrakt: Background: An outbreak of Legionella pneumonia occurred at a university hospital using copper-silver ionization for potable water disinfection. We present the epidemiological and laboratory investigation of the outbreak, and associated case-control study.
Methods: Cases were defined by syndrome compatible with Legionella pneumonia with laboratory-confirmed Legionella infection. The water circuit and disinfection system were assessed, and water samples collected for Legionella culture. Whole genome multi-locus sequence typing (wgMLST) was used to compare the genetic similarity of patient and environmental isolates. A case-control study was conducted to identify risk factors for Legionella pneumonia.
Results: We identified 13 cases of hospital-acquired Legionella. wgMLST revealed >99.9% shared allele content among strains isolated from clinical and water samples. Smoking (P= .008), steroid use (P= .007), and documented shower during hospitalization (P= .03) were risk factors for Legionella pneumonia on multivariable analysis. Environmental assessment identified modifications to the hospital water system had occurred in the month preceding the outbreak. Multiple mitigation efforts and application of point of use water filters stopped the outbreak.
Conclusions: Potable water system Legionella colonization occurs despite existing copper-silver ionization systems, particularly after structural disruptions. Multidisciplinary collaboration and direct monitoring for Legionella are important for outbreak prevention. Showering is a modifiable risk factor for nosocomial Legionella pneumonia. Shower restriction and point-of-use filters merit consideration during an outbreak.
(Copyright © 2021 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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