Legionella feeleii has rarely been reported as causing pneumonia in patients with hematologic malignancies. We present a case of Legionella feeleii serotype 2 pneumonia with empyema in a man with chronic lymphocytic leukemia and describe the methods of identifying this organism using both standard methods and newer diagnostic techniques.
CASE REPORTA 53-year-old white man presented to the National Institutes of Health, Bethesda, MD, to start his fourth cycle of fludarabine and rituximab for chronic lymphocytic leukemia (CLL). He had been diagnosed with CLL in 1998 but had only been started on chemotherapy 3 months prior to this admission when he experienced fatigue, anorexia, progressive lymphadenopathy, and a new left pleural effusion. On this presentation to the hospital, the patient complained of 7 days of fevers (39°C to 40°C), chills, a dry nonproductive cough, sharp rightsided lower back pain when lying down, and drenching night sweats. He denied diarrhea and had had no sick contacts. He had had a dental cleaning 7 days prior to the onset of these symptoms. He lived in Montana, where he worked in an officebased job in the construction industry, was a nonsmoker, had no pets, and had never received either a pneumococcal or influenza vaccine.The patient was nontoxic appearing and able to speak in full sentences. His temperature on admission was 38.4°C, blood pressure 115/69 mm Hg, heart rate 102 beats per minute, and respiratory rate 20 breaths per minute, with an oxygen saturation of 95% on ambient air. His examination was unremarkable, with clear breath sounds bilaterally without rhonchi or wheezes. He had mild leukopenia (white blood cell count of 2,800 cells/l, 69% neutrophils, 14% lymphocytes, and 13% monocytes), mild anemia (hemoglobin, 9.7 g/dl), and moderately elevated liver enzymes (aspartate aminotransferase, 58 IU/liter; alanine aminotransferase, 82 IU/liter). Immunoglobulins were low (IgG level, 323 mg/dl; IgA, 21 mg/dl; IgM, 14 mg/dl). A computed tomography (CT) scan of the chest showed bilateral hilar lymphadenopathy, a small leftsided pleural effusion, airspace disease in the right lower lobe with loculated effusions, and an area of cavitation (Fig. 1).Bronchoscopy revealed scant white secretions, and the bronchioalveolar lavage (BAL) fluid showed moderate neutrophils, few Gram-negative bacilli, no acid-fast or modified acid-fast bacilli, and a few budding yeast. A thoracentesis yielded cloudy, amber pleural fluid. The pleural fluid showed a white blood cell count of 8,350 cells/l (65% neutrophils), a glucose level of 80 mg/dl, a lactate dehydrogenase level of 945 U/liter, and a total protein level of 3.5 g/dl, consistent with an exudative effusion. After the procedures, ceftriaxone and azithromycin were initiated for community-acquired pneumonia. The patient became afebrile within 24 h of admission and did not require any supplemental oxygen. In-house real-time PCR performed on the BAL fluid was negative for both Legionella pneumophila serogroups 1 to 16 (mip gene) and Pneumocystis jirovecii (...