Listeria monocytogenes-associated respiratory infections: a study of 38 consecutive cases

International audience ; Objectives: Listeria monocytogenes (Lm) is a foodborne human pathogen responsible for severe infections, including septicaemia, neurolisteriosis, and maternalefoetal and focal infections. Little is known about Lm-associated respiratory tract or lung infections. Methods: We conducted a retrospective study of culture-proven cases of Lm pleural infections and pneumonia Results: Thirty-eight consecutive patients with pleural infection (n ¼ 32), pneumonia (n ¼ 5), or both (n ¼ 1) were studied; 71% of these were men. Median age was 72 (range 29e90). Two patients presented with concomitant neurolisteriosis. All patients but one reported at least one immunosuppressive condition (97%), with a median number of 2 (range 0e5), including 29% (8/28) with current exposure to immunosuppressive therapy and 50% (17/34) with ongoing neoplasia; 75% (21/28) reported previous pleural or pulmonary disease. Antibiotic therapy mostly consisted in amoxicillin (72%) associated with aminoglycoside in 32%. Chest-tube drainage was performed in 7/19 patients with empyema (37%); 25% of the patients (7/30) required intensive care management. In-hospital mortality reached 35% and occurred after a median time interval of 4 days (range 1e33 days). Three patients had recurrence of empyema (time interval of 1 week to 4 months after treatment completion). Altogether, only 13/31 patients (42%) diagnosed with Lm respiratory infection experienced an uneventful outcome at 2-year follow-up. Conclusion: Lm is a rare but severe cause of pneumonia and pleural infection in older immunocom-promised patients, requiring prompt diagnosis and adequate management and follow-up.