scholarly journals Lessons From an Outbreak of Legionnaires’ Disease on a Hematology-Oncology Unit

2016 ◽  
Vol 38 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Louise K. Francois Watkins ◽  
Karrie-Ann E. Toews ◽  
Aaron M. Harris ◽  
Sherri Davidson ◽  
Stephanie Ayers-Millsap ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Single Case ◽  
Healthcare Providers ◽  
Water System ◽  
Positive Sequence ◽  
Environmental Isolates ◽  
Legionnaires Disease ◽  
Oncology Unit ◽  
Healthcare Associated

OBJECTIVESTo define the scope of an outbreak of Legionnaires’ disease (LD), to identify the source, and to stop transmission.DESIGN AND SETTINGEpidemiologic investigation of an LD outbreak among patients and a visitor exposed to a newly constructed hematology-oncology unit.METHODSAn LD case was defined as radiographically confirmed pneumonia in a person with positive urinary antigen testing and/or respiratory culture forLegionellaand exposure to the hematology-oncology unit after February 20, 2014. Cases were classified as definitely or probably healthcare-associated based on whether they were exposed to the unit for all or part of the incubation period (2–10 days). We conducted an environmental assessment and collected water samples for culture. Clinical and environmental isolates were compared by monoclonal antibody (MAb) and sequence-based typing.RESULTSOver a 12-week period, 10 cases were identified, including 6 definite and 4 probable cases. Environmental sampling revealedLegionella pneumophilaserogroup 1 (Lp1) in the potable water at 9 of 10 unit sites (90%), including all patient rooms tested. The 3 clinical isolates were identical to environmental isolates from the unit (MAb2-positive, sequence type ST36). No cases occurred with exposure after the implementation of water restrictions followed by point-of-use filters.CONCLUSIONSContamination of the unit’s potable water system with Lp1 strain ST36 was the likely source of this outbreak. Healthcare providers should routinely test patients who develop pneumonia at least 2 days after hospital admission for LD. A single case of LD that is definitely healthcare associated should prompt a full investigation.Infect Control Hosp Epidemiol2017;38:306–313

Nosocomial Outbreak of Legionnaires' Disease: Molecular Epidemiology and Disease Control Measures

1987 ◽  
Vol 8 (2) ◽  
pp. 53-58 ◽  
Author(s):  
Jeffrey M. Johnston ◽  
Robert H. Latham ◽  
Frederick A. Meier ◽  
Jon A. Green ◽  
Rebecca Boshard ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Cooling Tower ◽  
Water System ◽  
Hot Water ◽  
Control Measures ◽  
Laboratory Techniques ◽  
Legionnaires Disease ◽  
Water Holding ◽  
Methods Of Control

AbstractMolecular laboratory techniques were used to study the epidemiology of an outbreak of nosocomial Legionnaires' disease. All patient isolates were Legionella pneumophila serogroup 1 and showed identical plasmid profiles and reactions with serogroup-specific monoclonal antibodies. L pneumophila was also cultured from four of five cooling tower water samples; however, the isolate from only one tower was serogroup 1 of the same sub-type as patient isolates. Since the cases were temporally clustered and epidemiologically associated with exposure to cooling tower aerosols, the single cooling tower implicated by molecular analysis was the most likely source of the outbreak. Chlorination of cooling tower ponds has eradicated the epidemic strain. Since potable water also harbored the infecting organism and was the probable source for cooling tower contamination, decontamination of the hospital water system was also undertaken. Superchlorination of hot water holding tanks to 17 ppm on a weekly basis has effectively eradicated L pneumophila from the potable water system and appears to be a reasonable, simple, and relatively inexpensive alternative to previously described methods of control.

scholarly journals Incrimination of an environmental source of a case of Legionnaires' disease by pyrolysis mass spectrometry

1991 ◽  
Vol 107 (1) ◽  
pp. 127-132 ◽  
Author(s):  
P. R. Sisson ◽  
R. Freeman ◽  
N. F. Lightfoot ◽  
I. R. Richardson
Keyword(s):  
Mass Spectrometry ◽  
Legionella Pneumophila ◽  
Water System ◽  
Hot Water ◽  
Pyrolysis Mass Spectrometry ◽  
Environmental Isolates ◽  
Relevant Reference ◽  
Cheap Method ◽  
Legionnaires Disease ◽  
Reference Strains

SUMMARYFollowing a case of Legionnaires' diseaseLegionella pneumophilaof the same serogroup was isolated from the hot water system of the hotel which had been epidemiologically implicated as the source of the infection. Pyrolysis mass spectrometry (PyMS) was used to compare 11 isolates from the hotel water sample with the patient's strain. Epidemiologically unrelated isolates, both clinical and environmental, of the same serogroup and monoclonal antibody type ofL. pneumophilawere included in the same analysis, together with relevant reference strains. The patient strain was shown to be indistinguishable from seven of the hotel water isolates, but clearly different from other unrelated clinical isolates, the reference strains and some of the other environmental isolates. PyMS is a rapid and cheap method for inter-strain comparison forL. pneumophila.

scholarly journals European Guidelines for Control and Prevention of Travel Associated Legionnaires' Disease: the Italian experience

2004 ◽  
Vol 9 (2) ◽  
pp. 10-11 ◽  
Author(s):  
M C Rota ◽  
M G Caporali ◽  
M Massari
Keyword(s):  
Legionella Pneumophila ◽  
Single Case ◽  
Water System ◽  
Control Measures ◽  
Environmental Investigation ◽  
European Guidelines ◽  
Italian Experience ◽  
Control And Prevention ◽  
Legionnaires Disease ◽  
Urinary Antigen Detection

In Italy, 35 clusters of travel associated Legionnaires' disease were identified from July 2002, when the European Guidelines for Control and Prevention of Travel Associated Legionnaires' Disease have been adopted by the EWGLINET network, to October 2003. Eight per cent (28.6%) would not have been identified without the network. The clusters detected were small, ranging from 2 cases to a maximum of 6. All clusters involved 5 camping sites and 30 hotels/residences, and an overall of 87 patients. The diagnosis was confirmed in 92.0% of the cases and mainly performed by urinary antigen detection (84.7%). A clinical isolate was available only in one case. Following environmental investigations, samples were collected for all the 35 clusters from the water system, and Legionella pneumophila was found in 23 occasions (65.7%). In 15 resorts out of 35, investigations were already in progress at the time of EWGLI cluster notification, since in Italy full environmental investigation is performed even after notification of a single case. Control measures were implemented in all accommodation sites at risk and one hotel only was closed. In all the 35 clusters, reports were completed and sent on time, highlighting that it is possible to comply with the procedures requested by the European Guidelines.

scholarly journals Prevalence of Infection-Competent Serogroup 6 Legionella pneumophila within Premise Plumbing in Southeast Michigan

mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Brenda G. Byrne ◽  
Sarah McColm ◽  
Shawn P. McElmurry ◽  
Paul E. Kilgore ◽  
Joanne Sobeck ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Water System ◽  
Disease Outbreaks ◽  
Clinical Isolates ◽  
Environmental Isolates ◽  
Urinary Antigen ◽  
Clinical Strains ◽  
Municipal Water ◽  
Premise Plumbing ◽  
Legionnaires Disease

ABSTRACTCoinciding with major changes to its municipal water system, Flint, MI, endured Legionnaires’ disease outbreaks in 2014 and 2015. By sampling premise plumbing in Flint in the fall of 2016, we found that 12% of homes harbored legionellae, a frequency similar to that in residences in neighboring areas. To evaluate the genetic diversity ofLegionella pneumophilain Southeast Michigan, we determined the sequence type (ST) and serogroup (SG) of the 18 residential isolates from Flint and Detroit, MI, and the 33 clinical isolates submitted by hospitals in three area counties in 2013 to 2016. Common to one environmental and four clinical samples were strains ofL. pneumophilaSG1 and ST1, the most prevalent ST worldwide. Among the Flint premise plumbing isolates, 14 of 16 strains were of ST367 and ST461, two closely related SG6 strain types isolated previously from patients and corresponding environmental samples. Each of the representative SG1 clinical strains and SG6 environmental isolates from Southeast Michigan infected and survived within macrophage cultures at least as well as a virulent laboratory strain, as judged by microscopy and by enumerating CFU. Likewise, 72 h after infection, the yield of viable-cell counts increased >100-fold for each of the representative SG1 clinical isolates, Flint premise plumbing SG6 ST367 and -461 isolates, and two Detroit residential isolates. We verified by immunostaining that SG1-specific antibody does not cross-react with the SG6L. pneumophilaenvironmental strains. Because the widely used urinary antigen diagnostic test does not readily detect non-SG1L. pneumophila, Legionnaires’ disease caused by SG6L. pneumophilais likely underreported worldwide.IMPORTANCEL. pneumophilais the leading cause of disease outbreaks associated with drinking water in the United States. Compared to what is known of the established risks of colonization within hospitals and hotels, relatively little is known about residential exposure toL. pneumophila. One year after two outbreaks of Legionnaires’ disease in Genesee County, MI, that coincided with damage to the Flint municipal water system, our multidisciplinary team launched an environmental surveillance and laboratory research campaign aimed at informing risk management strategies to provide safe public water supplies. The most prevalentL. pneumophilastrains isolated from residential plumbing were closely related strains of SG6. In laboratory tests of virulence, the SG6 environmental isolates resembled SG1 clinical strains, yet they are not readily detected by the common diagnostic urinary antigen test, which is specific for SG1. Therefore, our study complements the existing epidemiological literature indicating that Legionnaires’ disease due to non-SG1 strains is underreported around the globe.

scholarly journals Legionnaires' Disease Outbreak at a Resort in Cozumel, Mexico

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Lee M. Hampton ◽  
Laurel Garrison ◽  
Jessica Kattan ◽  
Ellen Brown ◽  
Natalia A. Kozak-Muiznieks ◽  
...  
Keyword(s):  
United States ◽  
Potable Water ◽  
Water System ◽  
Disease Outbreak ◽  
Community Acquired Pneumonia ◽  
Health Departments ◽  
Medical Providers ◽  
Cozumel Island ◽  
European Working ◽  
Legionnaires Disease

Abstract Background.  A Legionnaires' disease (LD) outbreak at a resort on Cozumel Island in Mexico was investigated by a joint Mexico-United States team in 2010. This is the first reported LD outbreak in Mexico, where LD is not a reportable disease. Methods.  Reports of LD among travelers were solicited from US health departments and the European Working Group for Legionella Infections. Records from the resort and Cozumel Island health facilities were searched for possible LD cases. In April 2010, the resort was searched for possible Legionella exposure sources. The temperature and total chlorine of the water at 38 sites in the resort were measured, and samples from those sites were tested for Legionella. Results.  Nine travelers became ill with laboratory-confirmed LD within 2 weeks of staying at the resort between May 2008 and April 2010. The resort and its potable water system were the only common exposures. No possible LD cases were identified among resort workers. Legionellae were found to have extensively colonized the resort's potable water system. Legionellae matching a case isolate were found in the resort's potable water system. Conclusions.  Medical providers should test for LD when treating community-acquired pneumonia that is severe or affecting patients who traveled in the 2 weeks before the onset of symptoms. When an LD outbreak is detected, the source should be identified and then aggressively remediated. Because LD can occur in tropical and temperate areas, all countries should consider making LD a reportable disease if they have not already done so.

scholarly journals Complete Genome Sequences of Six Legionella pneumophila Isolates from Two Collocated Outbreaks of Legionnaires’ Disease in 2005 and 2008 in Sarpsborg/Fredrikstad, Norway

2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Marius Dybwad ◽  
Tone Aarskaug ◽  
Else-Marie Fykse ◽  
Elisabeth Henie Madslien ◽  
Janet Martha Blatny
Keyword(s):  
Comparative Genomics ◽  
Genetic Relationship ◽  
Legionella Pneumophila ◽  
Complete Genome ◽  
Sequence Similarity ◽  
Secretion Systems ◽  
Environmental Isolates ◽  
Genome Sequences ◽  
High Sequence Similarity ◽  
Legionnaires Disease

Here, we report the complete genome sequences of Legionella pneumophila isolates from two collocated outbreaks of Legionnaires’ disease in 2005 and 2008 in Sarpsborg/Fredrikstad, Norway. One clinical and two environmental isolates were sequenced from each outbreak. The genome of all six isolates consisted of a 3.36 Mb-chromosome, while the 2005 genomes featured an additional 68 kb-episome sharing high sequence similarity with the L. pneumophila Lens plasmid. All six genomes contained multiple mobile genetic elements including novel combinations of type-IVA secretion systems. A comparative genomics study will be launched to resolve the genetic relationship between the L. pneumophila isolates.

Comparison of two molecular methods used for subtyping of Legionella pneumophila 1 strains isolated from a hospital water supply

2008 ◽  
Vol 58 (3) ◽  
pp. 683-688 ◽  
Author(s):  
B. Casini ◽  
P. Valentini ◽  
A. Baggiani ◽  
F. Torracca ◽  
C. Lorenzini ◽  
...  
Keyword(s):  
Water Supply ◽  
Legionella Pneumophila ◽  
Potable Water ◽  
Water System ◽  
Epidemiological Studies ◽  
Molecular Methods ◽  
Pfge Analysis ◽  
Typing Method ◽  
Electrophoretic Patterns ◽  
Low Degree

The results of the pulsed-field gel electrophoresis and the sequence-based typing (using the loci flaA, pilE, asd, mip, mompS and proA) were compared for subtyping of Legionella pneumophila 1 strains isolated from a hospital water supply. Molecular typing was carried out on 61 isolates (38% of the positive samples) selected on space and temporal criteria in order to follow the evolution of the water-system colonization. For all the 61 isolates, the sequence of the amplified mip gene fragment identified Legionella pneumophila strain Wadsworth. Genotype testing by PFGE analysis showed three different patterns, correspondent to three SBT types according to the allelic profiles. Both PFGE and SBT indicated the circulation and the persistence in the hospital potable water-system of three types randomly distributed in space and time. The two molecular methods adopted showed a 100% concordance, although a low degree of genetic heterogeneity characterized the isolates. The electrophoretic patterns were sufficiently unambiguous to consider PFGE a highly discriminatory typing method, but the SBT technique besides accurately characterizing isolates, was able to identify Legionella strains through analysis of the mip gene. A typing method with this level of discriminatory power has great potential for assisting in epidemiological studies.

scholarly journals Nosocomial legionella pneumonia: demonstration of potable water as the source of infection

1988 ◽  
Vol 101 (3) ◽  
pp. 647-654 ◽  
Author(s):  
B. Ruf ◽  
D. Schürmann ◽  
I. Horbrach ◽  
K. Seodel ◽  
H. D. Pohle
Keyword(s):  
Monoclonal Antibodies ◽  
Water Supply ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Potable Water ◽  
Supply System ◽  
University Hospital ◽  
Environmental Isolates ◽  
Legionella Pneumonia ◽  
Source Of Infection

SUMMARYFrom January 1983 until December 1985, 35 cases of sporadic nosocomial legionella pneumonia, all caused byLegionella pneumophila, were diagnosed in a university hospital.L. pneumophilaserogroup (SG) 1 was cultured from 12 of the 35 cases and compared to correspondingL. pneumophilaSG 1 isolates from water outlets in the patients' immediate environment by subtyping with monoclonal antibodies. The corresponding environmental isolates were identical to 9 out of 12 (75%) of those from the cases. However, even in the remaining three cases identical subtypes were found distributed throughout the hospital water supply. From the hospital water supply four different subtypes ofL. pneumophilaSG 1 were isolated, three of which were implicated in legionella pneumonia. Of 453 water samples taken during the study 298 (65.8%) were positive for legionellae. Species ofLegionellaother thanL. pneumophilahave not been isolated. This may explain the exclusiveness ofL.pneumophilaas the legionella pneumonia-causing agent. Our results suggest that the water supply system was the source of infection.

scholarly journals Lab Diagnosis of Legionnaires’ Disease

JMS SKIMS ◽  
2014 ◽  
Vol 17 (2) ◽  
pp. 50-54
Author(s):  
Nayeem U-Din Wani ◽  
Aamir Ali
Keyword(s):  
Legionella Pneumophila ◽  
Water System ◽  
Laboratory Diagnosis ◽  
Significant Rise ◽  
Control Measures ◽  
Causative Organism ◽  
Common Source ◽  
Contaminated Water ◽  
Atypical Pneumonia ◽  
Legionnaires Disease

Legionnaires’ disease is a multi-system disease which causes atypical pneumonia due to Legionella bacteria, most commonly of the species Legionella pneumophila. About one out of every 10 people who get sick from Legionnaires’ disease will die. Most common source of infection-contaminated water supply through inhalation of contaminated water droplets (aerosols). A laboratory diagnosis of Legionnaires’ disease can be made using a variety of laboratory tests including: culture/isolation of the causative organism, antigen detection in urine, a significant rise in antibody titres or PCR methods. Determination of the monoclonal subtype and molecular sequence typing can support linking between strains from the sampled environment and from patients. The control measures available to reduce the amount of Legionella in a water system include structural adaptations to the water system, temperature control, disinfection using chemicals or other oxidizing materials, and use of biocides or installation of filters. JMS 2014;17(2):50-54

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