Publication Date


Date of Final Oral Examination (Defense)


Type of Culminating Activity


Degree Title

Master of Science in Health Science


Community and Environmental Health

Major Advisor

Kirk Ketelsen, Ph.D.


Uwe Reischl, Ph.D., MD


Lutana Haan, MHS, RRT, RPSGT


Legionella is a bacterium found naturally in moist environments. Persons can become infected when they inhale airborne droplets of water containing such bacteria. Legionellosis cases associated with the use of respiratory devices such as Continuous Positive Airway Pressure (CPAP) units, jet nebulizers, portable room humidifiers, and respiratory ventilation equipment have been identified in context of a Legionellosis outbreak. However, a systematic search for the presence of Legionella bacteria in respiratory devices outside of a Legionellosis outbreak has not been reported. The goal of this study was to carry out such a survey on different types of respiratory devices in long term care facilities. Twenty-four respiratory devices including 9 CPAP, 4 BIPAPs, 5 oxygen humidifiers, and 6 ventilators were included in this study. A total of 72 sampling swabs were obtained for the testing of Legionella bacteria inside the respiratory devices. Culture and PCR tests for Legionella pneumophelia were made in tandem. No legionella pneumophelia bacteria were found in any of the respiratory devices sampled. Although there have been reports in the past of potential legionellosis cases associated with the use of respiratory devices, our data suggest that there are probably no legionella bacteria present inside respiratory devices separate of a Legionellosis outbreak.