Award Date


Degree Type


Degree Name

Master of Public Health (MPH)


Environmental Science

First Committee Member

Mark Buttner

Second Committee Member

Shawn Gerstenberger

Third Committee Member

Timothy Bungum

Fourth Committee Member

Daniel Young

Number of Pages



This project is an evaluation of a new, more proactive approach to legionellosis investigations conducted by the Southern Nevada Health District. The new protocol was conceived, written and adopted in April of 2012 with the goal of preventing outbreaks of Legionnaires' disease that can have a significant impact on public health and the resort industry of Las Vegas. The objectives of this project were to determine if the remediation methods were successful at eliminating the target organism from water systems and maintaining a negative status throughout the monitoring period, to conduct a cost/benefit analysis, and to compare this protocol with other proactive health department protocols.

Ninety percent of facilities found to be sources were able to obtain and maintain a negative target organism status throughout the monitoring period, indicating that the remediation methods are effective. There was no significant difference between the remediation methods (hot water flush, chlorine flush or both) in obtaining and maintaining negative results for Legionella. This evaluation also found that average yearly costs for SNHD increased from about $5,611 a year on legionellosis investigations to about $82,675. An estimate of the cost to all facilities investigated since implementation is $1,466,000 with an approximate total cost to SNHD and facilities of $1,590,013. This is a minor investment when compared with the significant healthcare costs of legionellosis illness and outbreaks in the U.S., which total $101-321 million per year. In addition, litigation awards can cost facilities hundreds of millions of dollars. No other health departments were identified that conduct this type of proactive investigation, and often only initiate an environmental investigation after a second case is found with an association to the same facility as a previous case. Often, by then it is too late to prevent outbreaks and additional illnesses associated with that facility. This evaluation shows that the new protocol is potentially a strong public health prevention tool for legionellosis outbreaks, that it is cost effective, and would be an excellent template for other local health agencies to adopt in order to better protect the health of the public.


Environmental investigation; Legionnaires' disease; Legionnaires' disease – Prevention; Legionella pneumophila; Legionnaires' disease; Nevada – Las Vegas; Remediation; Southern Nevada Health District


Bacterial Infections and Mycoses | Environmental Public Health | Public Health | Respiratory Tract Diseases

File Format


Degree Grantor

University of Nevada, Las Vegas




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