208883 Legionnaires Disease & Pontiac Fever Outbreak in a City Garage: A Retrospective Cohort Study

Tuesday, November 10, 2009

Renee' Witcher-Johnson, MPH , Office of Communicable Disease Surveillance & Epidemiology, Cleveland Department of Public Health, Cleveland, OH
Objective: Determine if an outbreak of Legionella pneumophila was associated to the city garage.

Background: In 2004 the Cleveland Department of Public Health received a report from a community member of individuals that worked in a city garage that were ill and hospitalized from Legionnaires Disease. One month following this account the Health Department received an additional report of a Legionnaires Disease case associated with a city garage. It was determined that these two cases were confirmed Legionnaires Disease cases through additional investigation.

Method: A retrospective cohort study was done to determine whether there was an association between environmental factors and illness. There were forty one participants in the outbreak study. Results: There were 18 environmental factors tested epidemiologically and environmentally. One of the hypotheses proposed indicated there is a significant association between sitting in the patio area near the steam jenny and legionnaire's disease or pontiac fever. This hypothesis was weakly associated p=.08. Additional sampling done on the water sources also yielded legionella, however isolates were unable to be sub typed and matched to the index case patient.

Discussion: It is often difficult to determine how individuals were exposed to legionella pneumophila. Although this outbreak is associated to the city facility in question it is often difficult to isolate the source on legionnaires due to the aspect of the pathogen and that it is sporadic in the environment as a whole.

Learning Objectives:
1. Describe the magnitude of legionella pneumophila as a pathogen in water reservoirs. 2. Explain the epidemiology of legionella pneumophila. 3. Understand methods to counter legionella pneumophila in water reservoirs.

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: Presenter: Masters in Public Health, Supervisor for the Office of Surveillance and Epidemiology (6 years with Cleveland Public Health). Epidemiologist for the Fresno County Community Health Department in California (2 years). Have done extensive data and spatial analysis of communicable disease data from surveillance data and outbreaks conducted in the Clevelenad area. Have led over 60 outbreaks over the years in the field of epidemiology in which data collection, analysis and development of data collection tools were demonstrated. Have submitted to APHA before related to Emergency preparedness and received an award for the poster session.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.