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

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.

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

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2016.281 ◽

2016 ◽

Vol 38 (3) ◽

pp. 306-313 ◽

Cited By ~ 6

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

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Lab Diagnosis of Legionnaires’ Disease

JMS SKIMS ◽

10.33883/jms.v17i2.240 ◽

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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Clusters of Healthcare-Associated Legionnaires’ Disease in Two Hospitals of Central Greece

Case Reports in Infectious Diseases ◽

10.1155/2018/2570758 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Maria A. Kyritsi ◽

Varvara A. Mouchtouri ◽

Anna Katsiafliaka ◽

Foteini Kolokythopoulou ◽

Elias Plakokefalos ◽

...

Keyword(s):

Legionella Pneumophila ◽

Environmental Samples ◽

Distribution Systems ◽

Water Distribution ◽

Control Measures ◽

Aerosol Therapy ◽

Environmental Investigation ◽

Source Of Infection ◽

Legionnaires Disease ◽

Healthcare Associated

Healthcare-associated Legionnaires’ disease often leads to fatal respiratory tract infection among hospitalized patients. In this report, three cases of Legionnaires’ disease among patients in two different hospitals (Hospital A and Hospital B) were investigated. After conducting an epidemiologic and environmental investigation, the water distribution systems (WDSs) were identified as the possible source of infection, as Legionella pneumophila serogroup 1 (Lp1) was isolated from both clinical and environmental samples. Patients received aerosol therapy with nebulizers during their hospitalization. Based on the results of the investigation, the hospitals’ infection control committees reviewed their policies for Legionnaires’ disease prevention and implemented control measures focusing on using sterile fluids for aerosol treatments.

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Legionella pneumophila in a hospital water system following a nosocomial outbreak: prevalence, monoclonal antibody subgrouping and effect of control measures

Epidemiology and Infection ◽

10.1017/s0950268800062002 ◽

1987 ◽

Vol 98 (3) ◽

pp. 253-262 ◽

Cited By ~ 18

Author(s):

C. D. Ribeiro ◽

S. H. Burge ◽

S. R. Palmer ◽

J. O'H. Tobin ◽

I. D. Watkins

Keyword(s):

Monoclonal Antibody ◽

Legionella Pneumophila ◽

Water Samples ◽

Water System ◽

Extended Period ◽

Control Measures ◽

Nosocomial Outbreak ◽

Water Supplies ◽

Chemical Sterilization ◽

Legionnaires Disease

SUMMARYSwabs and water samples from a hospital water system were cultured for legionellae over an extended period. Legionella pneumophila serogroup 1, including outbreak associated strains, were isolated in small numbers from approximately 5% of these samples despite implementation of the current DHSS/Welsh Office regulations. No cases of nosocomial legionnaires' disease were proven during the study. Physical cleaning and chemical sterilization of taps, and replacement of washers with ‘approved’ brands did not eradicate the organisms. Eradication of legionellae in hospital water supplies appears to be unnecessary in preventing nosocomial legionnaires' disease provided the current DHSS/Welsh Office recommendations are implemented.

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The Stafford outbreak of Legionnaires’ disease

Epidemiology and Infection ◽

10.1017/s0950268800047385 ◽

1990 ◽

Vol 104 (3) ◽

pp. 361-380 ◽

Cited By ~ 65

Author(s):

M. C. O'Mahony ◽

R. E. Stanwell-Smith ◽

H. E. Tillett ◽

D. Harper ◽

J. G. P. Hutchison ◽

...

Keyword(s):

Legionella Pneumophila ◽

Air Conditioning ◽

Cooling Tower ◽

Ventilation System ◽

Water System ◽

Cooling Water ◽

District General Hospital ◽

Control Measures ◽

Epidemic Strain ◽

Legionnaires Disease

SUMMARYA large outbreak of Legionnaires’ disease was associated with Stafford District General Hospital. A total of 68 confirmed cases was treated in hospital and 22 of these patients died. A further 35 patients, 14 of whom were treated at home, were suspected cases of Legionnaires’ disease. All these patients had visited the hospital during April 1985. Epidemiological investigations demonstrated that there had been a high risk of acquiring the disease in the out patient department (OPD), but no risk in other parts of the hospital. The epidemic strain ofLegionella pneumophila, serogroup 1, subgroup Pontiac la was isolated from the cooling water system of one of the air conditioning plants. This plant served several departments of the hospital including the OPD. The water in the cooling tower and a chiller unit which cooled the air entering the OPD were contaminated with legionellae. Bacteriological and engineering investigations showed how the chiller unit could have been contaminated and how an aerosol containing legionellae could have been generated in the U–trap below the chiller unit. These results, together with the epidemiological evidence, suggest that the chiller unit was most likely to have been the major source of the outbreak.Nearly one third of hospital staff had legionella antibodies. These staff were likely to have worked in areas of the hospital ventilated by the contaminated air conditioning plant, but not necessarily the OPD. There was evidence that a small proportion of these staff had a mild legionellosis and that these ‘influenza–like’ illnesses had been spread over a 5–month period. A possible explanation of this finding is that small amounts of aerosol from cooling tower sources could have entered the air–intake and been distributed throughout the areas of the hospital served by this ventilation system. Legionellae, subsequently found to be of the epidemic strain, had been found in the cooling tower pond in November 1984 and thus it is possible that staff were exposed to low doses of contaminated aerosol over several months.Control measures are described, but it was later apparent that the outbreak had ended before these interventions were introduced. The investigations revealed faults in the design of the ventilation system.

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

Infection Control ◽

10.1017/s0195941700067072 ◽

1987 ◽

Vol 8 (2) ◽

pp. 53-58 ◽

Cited By ~ 11

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.

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Travel-associated Legionnaires’ disease: would changing cluster definition lead to the prevention of a larger number of cases?

Epidemiology and Infection ◽

10.1017/s0950268818003266 ◽

2018 ◽

Vol 147 ◽

Cited By ~ 1

Author(s):

M. C. Rota ◽

A. Bella ◽

M. G. Caporali ◽

A. Nicolau ◽

V. Drasar ◽

...

Keyword(s):

Legionella Pneumophila ◽

Disease Surveillance ◽

Control Measures ◽

Surveillance Network ◽

Stringent Control ◽

European Guidelines ◽

Increased Risk ◽

Legionnaires Disease ◽

And Control ◽

Full Investigation

AbstractAccording to European Guidelines for Legionnaires’ Disease prevention and control, travel-associated Legionnaires’ disease (TALD) cases are managed differently if classified as sporadic or as part of a cluster and more stringent control measures are deployed after clusters are identified. In this study, we propose to modify the current cluster definition: ‘two or more cases of Legionnaires’ disease (LD) who stayed at, or visited, the same commercial accommodation site 2–10 days before onset of illness and whose onset is within the same 2-year period’ with a new cluster definition, i.e. accommodation sites associated with multiple cases regardless of the time elapsed between them. TALD cases occurred in Italy and in the Balearic Islands between 2005 and 2015 were analysed applying the current European Legionnaires’ Disease Surveillance Network (ELDSNet) cluster definition. In a sample of selected accommodation sites with multiple cases, a microbiological study was also conducted. Using the new definition, 63 additional sites (16.4% increase) and 225 additional linked cases (19.5% increase) were identified.Legionella pneumophilasg1 was isolated from 90.7% of the selected accommodation sites. The use of the here proposed TALD cluster definition would warrant a full investigation for each new identified case. This approach should therefore increase the number of sites that will require a risk assessment and, in the presence of an increased risk, the adoption of LD control measures to hopefully prevent additional cases.

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Legionnaires’ disease cluster linked to a metal product aqueous pre-treatment process, Staffordshire, England, May 2008

Eurosurveillance ◽

10.2807/ese.14.40.19348-en ◽

2009 ◽

Vol 14 (40) ◽

Author(s):

N Coetzee ◽

W K Liu ◽

N Astbury ◽

P Williams ◽

S Robinson ◽

...

Keyword(s):

Legionella Pneumophila ◽

Treatment Process ◽

Medical Practitioners ◽

Disease Cluster ◽

Environmental Investigation ◽

Worker Absenteeism ◽

Community Exposure ◽

Legionnaires Disease ◽

Pre Treatment ◽

Biocide Treatment

In May 2008, a report of two workers from the same construction equipment manufacturing plant who were admitted to hospital with Legionnaires’ disease confirmed by urine antigen prompted an outbreak investigation. Both cases were middle aged men, smokers, and with no travel, leisure or other common community exposure to Legionella sources. There were no wet cooling towers at the plant or in the surrounding area. No increase in respiratory disease or worker absenteeism occurred at the plant during the preceding month. Wider case ascertainment including alerts to hospitals and medical practitioners yielded no further cases. The environmental investigation (and sampling of water systems for Legionella) identified a Legionella pneumophila serogroup1 (Mab 2b) count of >3.0x104cfu/l in water samples from an aqueous metal pre-treatment tunnel, which generates profuse water aerosol. Drainage, cleaning and biocide treatment using thiazalone eliminated Legionella from the system.

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Clusters of travel associated legionnaires' disease in France, September 2001- August 2003

Eurosurveillance ◽

10.2807/esm.09.02.00446-en ◽

2004 ◽

Vol 9 (2) ◽

pp. 12-13 ◽

Cited By ~ 4

Author(s):

B Decludt ◽

C Campese ◽

◽

...

Keyword(s):

Legionella Pneumophila ◽

Control Measures ◽

Local Health ◽

Surveillance Network ◽

Health Authorities ◽

Legionnaires Disease ◽

Risk Of Exposure ◽

Local Health Authorities ◽

Tourist Accommodation ◽

National Surveillance System

Clusters of travel associated legionnaires' disease warrant urgent attention, and are detected by the French national surveillance system and the European network EWGLINET. Between September 2001 and August 2003, 37 clusters were identified in French tourist accommodation: 27 hotels and 10 campsites. The number of clinical cases per cluster was as follows: 30 clusters of 2 cases (81%), 6 clusters of 3 cases (16%) and one cluster of 4 cases (3%), a total of 82 cases. The local health authorities performed environmental investigations for 36 of the 37 clusters. Among the 36 clusters investigated, water samples were collected for 35. At 16 (46%) sites, Legionella pneumophila was found at a level of more than 103 cfu/litre. In all of the accommodation where risk assessment was found to be inadequate- control measures were implemented immediately. Six hotels were closed immediately following cluster alerts. Comparison of clinical and environmental isolates by pulsed field gel electrophoresis (PFGE) was possible in 3 clusters and identical genomic profiles of the isolates were found in all. During this two year period of surveillance, we found that on many sites there has been a risk of exposure to Legionella. This reinforces the importance of the European surveillance network and the timely notifications of all the cases to EWGLINET.

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