Severe Legionella pneumophila pneumonia associated with the public bath on a cruise ship in Japan.

Abstract

SpO2 was 80% (ambient air) on admission, he was transferred to the intensive care unit (ICU). Because of his progressive respiratory failure, tracheal intubation and mechanical ventilation was needed, with continuous intravenous administration of propofol. Arterial gas analysis with ventilatory support (FIO2 1.0; PEEP, 5cmH2O; SIMV 18min 1) showed pH 7.48, PaO2 66mmHg, and PaCO2 55mmHg. A chest radiograph revealed bilateral diffuse pneumonia with existing emphysema. A computed tomogram (CT) of the chest revealed multiple areas of infiltration. Laboratory examination showed a leukocyte count of 16500/mm3; C-reactive protein (CRP) level was 36.4mg/dl and total bilirubin level was 2.6 mg/dl. The administration of panapenem (1g/day i.v.) was started. On hospital day 1, we obtained a specimen for determination of the causative microorganism by bronchoendscopy, but culture of the aspirated fluid showed no significant growth of organisms. Based on this finding, with the characteristics of the chest radiograph, we suspected interstitial pneumonia, and methylrednislone (1g/day) was given for 3 days. In spite of the treatment, the infiltrative shadow grew, and the patient’s oxygenation remained unimproved. His condition continued to deteriorate, with ongoing multiple organ failure (MOF) and refractory hypotension. On hospital day 4, Legionella pneumophila was isolated from culture of the sputum on buffered charcoal yeast extract with alpha-ketoglutarate (BCYE-α) agar plates. Culture of bronchial lavage was positive for L. pneumophila serogroup 5. After confirmation of these colonies, the antibiotic administration was switched to erythromycin (2000mg/day i.v.), ciprofloxacin (400mg/day i.v.), and rifampicin (450mg/day p.o.) in combination. Specific urinary antigen detection of L. pneumophila was later reported to be positive (Binax, Portland, ME, USA). His condition was ameliorated dramatically after the changing of antibiotics. Arterial gas analysis with ventilatory support (FIO2, 0.4; CPAP