Vital Signs: Deficiencies in Environmental Control Identified in Outbreaks of Legionnaires’ Disease — North America, 2000–2014

Garrison, Laurel E.; Kunz, Jasen; Cooley, Laura A.; Moore, Matthew R.; Lucas, Claressa E.; Schrag, Stephanie J.; Sarisky, John; Whitney, Cynthia G.

doi:10.15585/mmwr.mm6522e1

Cited by 138 publications

(124 citation statements)

References 11 publications

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“…All of the outbreak-associated deaths reported during this surveillance period as well as all of the outbreaks reported in hospital/health care settings or long-term care facilities, were caused by Legionella . A review of 27 Legionnaires’ disease outbreak investigations in which CDC participated during 2000–2014 identified at least one water system maintenance deficiency in all 23 investigations for which this information was available, indicating that effective water management programs in buildings at increased risk for Legionella growth and transmission (e.g., those with more than 10 stories or that house susceptible populations) can reduce the risk for Legionnaires’ disease ( 5 , 6 ). Although Legionella was detected in drinking water, multiple routes of transmission beyond ingestion of contaminated water more likely contributed to these outbreaks, such as aerosolization from domestic or environmental sources.…”

Section: Discussionmentioning

confidence: 99%

Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water — United States, 2013–2014

Benedict¹,

Reses²,

Vigar³

et al. 2017

MMWR Morb. Mortal. Wkly. Rep.

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212

136

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Section: Discussionmentioning

confidence: 99%

Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water — United States, 2013–2014

Benedict¹,

Reses²,

Vigar³

et al. 2017

MMWR Morb. Mortal. Wkly. Rep.

Self Cite

212

136

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“…The colony counts therefore show the ability of L. pneumophila to proliferate under the test conditions. L. pneumophila is the major causative agent of LD (1,2). Currently, about 2,200 sequence types (STs) of this species have been identified (http://bioinformatics.phe.org.uk/legionella/legionella_sbt/php/ sbt_homepage.php), most of which have not been implicated in LD (71).…”

Section: Discussionmentioning

confidence: 99%

Biofilm Composition and Threshold Concentration for Growth of Legionella pneumophila on Surfaces Exposed to Flowing Warm Tap Water without Disinfectant

Kooij

Bakker²,

Italiaander

et al. 2017

Appl Environ Microbiol

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Legionella pneumophila in potable water installations poses a potential health risk, but quantitative information about its replication in biofilms in relation to water quality is scarce. Therefore, biofilm formation on the surfaces of glass and chlorinated polyvinyl chloride (CPVC) in contact with tap water at 34 to 39°C was investigated under controlled hydraulic conditions in a model system inoculated with biofilm-grown L. pneumophila. The biofilm on glass (average steady-state concentration, 23 Ϯ 9 pg ATP cm Ϫ2 ) exposed to treated aerobic groundwater (0.3 mg C liter Ϫ1 ; 1 g assimilable organic carbon [AOC] liter Ϫ1 ) did not support growth of the organism, which also disappeared from the biofilm on CPVC (49 Ϯ 9 pg ATP cm Ϫ2 ) after initial growth. L. pneumophila attained a level of 4.3 log CFU cm Ϫ2 in the biofilms on glass (1,055 Ϯ 225 pg ATP cm Ϫ2 ) and CPVC (2,755 Ϯ 460 pg ATP cm Ϫ2 ) exposed to treated anaerobic groundwater (7.9 mg C liter Ϫ1 ; 10 g AOC liter Ϫ1 ). An elevated biofilm concentration and growth of L. pneumophila were also observed with tap water from the laboratory. The Betaproteobacteria Piscinibacter and Methyloversatilis and amoeba-resisting Alphaproteobacteria predominated in the clones and isolates retrieved from the biofilms. In the biofilms, the Legionella colony count correlated significantly with the total cell count (TCC), heterotrophic plate count, ATP concentration, and presence of Vermamoeba vermiformis. This amoeba was rarely detected at biofilm concentrations of Ͻ100 pg ATP cm Ϫ2 . A threshold concentration of approximately 50 pg ATP cm Ϫ2 (TCC ϭ 1 ϫ 10 6 to 2 ϫ 10 6 cells cm Ϫ2 ) was derived for growth of L. pneumophila in biofilms.IMPORTANCE Legionella pneumophila is the etiologic agent in more than 10,000 cases of Legionnaires' disease that are reported annually worldwide and in most of the drinking water-associated disease outbreaks reported in the United States. The organism proliferates in biofilms on surfaces exposed to warm water in engineered freshwater installations. An investigation with a test system supplied with different types of warm drinking water without disinfectant under controlled hydraulic conditions showed that treated aerobic groundwater (0.3 mg liter Ϫ1 of organic carbon) induced a low biofilm concentration that supported no or very limited growth of L. pneumophila. Elevated biofilm concentrations and L. pneumophila colony counts were observed on surfaces exposed to two types of extensively treated groundwater, containing 1.8 and 7.9 mg C liter Ϫ1 and complying with the microbial water quality criteria during distribution. Control measures in warm tap water installations are therefore essential for preventing growth of L. pneumophila.

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“…There were no common buildings visited by case patients, and case residences were spread across a 6.5 mi 2 area.” Officials then began operating under the working theory that those who had gotten sick were being exposed outdoors. Cooling towers have been implicated in prior LD outbreaks, both in NYC and elsewhere 15. The hypothesis that a cooling tower was the source of the outbreak allowed officials to focus the scope of the environmental investigation.…”

Section: South Bronx Outbreak: July 2015mentioning

confidence: 99%

The 2015 New York City Legionnaires' Disease Outbreak: A Case Study on a History-Making Outbreak

Chamberlain

Lehnert

Berkelman

2017

Journal of Public Health Management and Practice

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Vital Signs: Deficiencies in Environmental Control Identified in Outbreaks of Legionnaires’ Disease — North America, 2000–2014

Cited by 138 publications

References 11 publications

Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water — United States, 2013–2014

Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water — United States, 2013–2014

Biofilm Composition and Threshold Concentration for Growth of Legionella pneumophila on Surfaces Exposed to Flowing Warm Tap Water without Disinfectant

The 2015 New York City Legionnaires' Disease Outbreak: A Case Study on a History-Making Outbreak

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