A case of nosocomial Legionella pneumonia associated with a contaminated hospital cooling tower.
We report the epidemiological investigation of a nosocomial pneumonia case due to Legionella pneumophila linked to a contaminated hospital cooling tower in an immune-compromised patient. A 73-year-old female patient was diagnosed with nosocomial Legionella pneumonia proven by a culture of L. pneumophila serogroup 1 from bronchoalveolar lavage fluid. Two strains isolated from the patient and two strains isolated from two cooling towers were found to be identical using repetitive-sequence-based-PCR with a 95% probability. This Legionella pneumonia case might be caused by aerosol from cooling towers on the roof of the hospital building which was contaminated by L. pneumophila. We increased up the temperature of hot water supply appropriately for prevention of Legionella breeding in an environment of patients' living. On the other hand, as the maintenance of cooling tower, we increased the frequency of Legionella culture tests from twice a year to three times a year. In addition, we introduced an automated disinfectants insertion machine and added one antiseptic reagent (BALSTER ST-40 N, Tohzai Chemical Industry Co., Ltd., Kawasaki, Japan) after this Legionella disease, and thereafter, we have no additional cases of Legionella disease or detection of Legionella spp. from the cooling tower or hot water supply. This case demonstrates the importance of detecting the infection source and carrying out environmental maintenance in cooperation with the infection control team.
Department of Infection Control and Prevention, Kobe University Hospital, Kobe, Japan.
Kayo
K
Osawa
Department of Infection Control and Prevention, Kobe University Hospital, Kobe, Japan; Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: yutoshunta@hotmail.co.jp.
Katsumi
K
Shigemura
Department of Infection Control and Prevention, Kobe University Hospital, Kobe, Japan.
Yasuhisa
Y
Abe
Department of Infection Control and Prevention, Kobe University Hospital, Kobe, Japan.
Takumi
T
Jikimoto
Department of Infection Control and Prevention, Kobe University Hospital, Kobe, Japan.
Hiroyuki
H
Yoshida
Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
Masato
M
Fujisawa
Department of Infection Control and Prevention, Kobe University Hospital, Kobe, Japan; Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
Soichi
S
Arakawa
D000368:Aged; D003428:Cross Infection / Q000382:microbiology*; D005260:Female; D006761:Hospitals; D006801:Humans; D016952:Legionella pneumophila / Q000302:isolation & purification*; D007877:Legionnaires' Disease / Q000382:microbiology*; D013696:Temperature
Cooling tower; Legionella; Nosocomial infection; Rep-PCR