Journal Article

Eight years of Legionnaires' disease transmission in travellers to a condominium complex in Las Vegas, Nevada

BROWN, E. W., WINCHESTER, J. L., FIELDS, B. S., LABUS, B. J., ROWLEY, P., MIDDAUGH, J. P., HICKS, L. A., SILK, B. J., MOORE, M. R., KOZAK, N. A., BERGTHOLDT, M., GORWITZ, R. J., THA, M. M.

2012

Overview

Travel is a risk factor for Legionnaires' disease. In 2008, two cases were reported in condominium guests where we investigated a 2001 outbreak. We reinvestigated to identify additional cases and determine whether ongoing transmission resulted from persistent colonization of potable water. Exposures were assessed by matched case-control analyses (2001) and case-series interviews (2008). We sampled potable water and other water sources. Isolates were compared using sequence-based typing. From 2001 to 2008, 35 cases were identified. Confirmed cases reported after the cluster in 2001–2002 were initially considered sporadic, but retrospective case-finding identified five additional cases. Cases were more likely than controls to stay in tower 2 of the condominium [matched odds ratio (mOR) 6·1, 95% confidence interval (CI) 1·6–22·9]; transmission was associated with showering duration (mOR 23·0, 95% CI 1·4–384). We characterized a clinical isolate as sequence type 35 (ST35) and detected ST35 in samples of tower 2's potable water in 2001, 2002, and 2008. This prolonged outbreak illustrates the importance of striving for permanent Legionella eradication from potable water.

• Publisher: Cambridge University Press
• Subject: Aged / Bacterial diseases / Bacterial diseases of the respiratory system / Biological and medical sciences / Case-Control Studies / Condominiums / Contact Tracing / Cooling / Disease control / Disease Outbreaks / Disease transmission / Drinking water / Drinking Water - microbiology / Epidemics / Epidemiology / Fundamental and applied biological sciences. Psychology / Guest rooms / Housing / Human bacterial diseases / Humans / Infectious diseases / Legionella / Legionella pneumophila - classification / Legionella pneumophila - isolation & purification / Legionnaire's disease / Legionnaires disease / Legionnaires' Disease - diagnosis / Legionnaires' Disease - epidemiology / Legionnaires' Disease - prevention & control / Legionnaires' Disease - transmission / Logistic Models / Medical laboratories / Medical sciences / Microbiology / Middle Aged / Multivariate Analysis / Nevada - epidemiology / Odds Ratio / Outbreaks / Pneumonia / Potable water / Preventive medicine / Public health / Resorts & spas / Respiratory infections / Retrospective Studies / Risk Factors / Serotyping / Surveillance / Swimming pools / Travel / Water heaters / Water Microbiology / Water samples / Water supply