[Community outbreak of pneumonia due to Legionella pneumophila: importance of monitoring hospital cooling towers].
OBJECTIVE
Description of an outbreak of legionnaires' disease originating in one of the cooling towers of a hospital.


METHODS
This study included patients with confirmed pneumonia caused by Legionella pneumophila serogroup 1 and related to the Vallcarca neighborhood of Barcelona (Spain) in August 2004. Exposure was determined by a standardized questionnaire. An environmental investigation was carried out to identify the source of the outbreak. A descriptive analysis including incidence rates estimation was performed, as well as molecular study to document the genetic identity among human and environmental strains.


RESULTS
Thirty-three cases of L. pneumophila pneumonia were detected. Median age was 68 years and 70% of the affected patients were men. Incidence rate among residents in less than 200 meters of the source and older than 65 was 888.9 cases/100,000 inhabitants. Lethality rate was 6%. Four seasonal cooling towers that were not registered with the authorities were identified in a health care center. L. pneumophila was isolated from all four and at least one colony in each tower had the same genetic profile as the strains isolated from patients.


CONCLUSIONS
An association was demonstrated between a community outbreak of legionellosis and unregistered seasonal cooling towers located in a hospital. All risk facilities should be registered and inspected to ensure that they fulfill current legislation requirements.
de Olalla
Patricia García
PG
Servicio de Epidemiología, Agència de la Salut Pública de Barcelona, España. polalla@aspb.es
Gracia
José
J
Rius
Cristina
C
Caylà
Joan A
JA
Pañella
Helena
H
Villabí
Joan R
JR
Guix
Joan
J
Pellicer
Teresa
T
Ferrer
Dolors
D
Cusi
Meritxell
M
Pelaz
Carmen
C
Sabrià
Miquel
M
D000336:Aerosols; D000368:Aged; D000369:Aged, 80 and over; D000391:Air Microbiology; D002028:Building Codes; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology / Q000635:transmission; D018563:Disease Notification; D004196:Disease Outbreaks; D004781:Environmental Exposure; D005260:Female; D006786:Hospitals, Urban / Q000331:legislation & jurisprudence; D006801:Humans; D015994:Incidence; D016952:Legionella pneumophila / Q000302:isolation & purification*; D007877:Legionnaires' Disease / Q000453:epidemiology* / Q000209:etiology / Q000635:transmission; D008297:Male; D008875:Middle Aged; D012034:Refrigeration; D013030:Spain / Q000453:epidemiology; D014504:Urban Health; D014871:Water Microbiology
D000336:Aerosols