Legionnaires' Disease Outbreak at a Long-Term Care Facility Caused by a Cooling Tower Using an Automated Disinfection System—Ohio, 2013


On July 9, 2013, an outbreak of Legionnaires’ disease (LD) was identified at Long-Term Care Facility A in central Ohio. This article describes the investigation of the outbreak and identification of the outbreak source, a cooling tower using an automated biocide delivery system. In total, 39 outbreak LD cases were identified; among these, six patients died. Water samples from a cooling tower were positive for Legionella pneumophila serogroup 1, reactive to monoclonal antibody 2, with matching sequence type to a patient isolate. An electronic control system turned off cooling tower pumps during low-demand periods, preventing delivery of disinfectant by a timed-release system, and leading to amplification of Legionella in the cooling tower. Guidelines for tower maintenance should address optimal disinfection when using automated systems.

Speaker / Author: 
Celia Quinn, MPH, MD
Alicia Demirian, MMSc, MD; Louise Francois Watkins, MPH, MD; and Sara Tomczyk, MSc, PHN
Claressa Lucas, PhD; Ellen Brown; Natalia Kozak-Muiznieks, PhD; and Laurel E. Garrison, MPH
Jasen Kunz, MPH
Scott Brewer, MPH and Samantha Eitnier, MPH
Mary DiOrio, MPH, MD
Month Year: 
December 2015
Page #: 
Publication Month: 
December 2015