WQ1401:             Innovative Methods to Control, Investigate, and Monitor for Legionella: A Panel Discussion

Speakers:            Mark Bergtholdt, MPH, REHS/RS; Paul A. Carballosa; Lisa Rogers


How does a tourism-dependent community respond to an environmental pathogen found in its water?  This session will introduce the basic ecology and pathogenicity of Legionella. A local engineer will share how a large hotel developed and implemented a waterborne pathogen control plan and the local health district will cover their approach to investigating single cases of Legionellosis.  Detection and monitoring methods will also be addressed, including a rapid bacteria screening method which provides a means for risk assessment and outbreak mitigation without waiting for a bacterial culture. See if this integrated approach could be applied to address Legionella concerns in your community.



Between 2005 and 2011, SNHD received reports of 66 single of Legionellosis from people who lived outside of Clark County but stayed in Las Vegas during their incubation period.  These 66 cases resulted in 4 investigations of outbreaks; 24 of the 66 cases were associated with these outbreaks. 

These investigations garnered both local and national media attention that was potentially detrimental to Las Vegas' tourism industry.  As a result of these incidents and to better protect the health of the Clark County's 43 million visitors per year and 2 million residents, SNHD developed an innovative and proactive response to investigating single cases of Legionellosis.  This protocol includes assessing the risk of the building being colonized by Legionella bacteria, administration of the CDC Environmental Assessment of Water Systems Tool and targeted sampling of potential exposures. 

Depending upon the results, SNHD makes recommendations to remediate the affected systems along with a follow-up sampling program.  This change in response was implemented in April 2012.  Between April 2012 and October 2013, SNHD investigated seventeen single cases with known Clark County exposure to Legionella with no outbreak investigations in sharp contrast to the 2005-2011 period.