Legionella pneumophila pneumonia: A 5-year retrospective clinical evaluation and commentary

Although legionellosis represents a widely underestimated disease for various reasons, the rate of Legionella pneumophila infections has increased steadily over the past 30 years. The present study describes the characteristics of patients hospitalized due to legionellosis. The present study retrospectively reviewed 10 cases of legionellosis during the defined period and documented the epidemiological and clinical characteristics of the patients, as well as the methods used for diagnosis and therapeutic management. The majority of the patients were male (80%) with a mean age of 55.8 years. The most common comorbidities were hypertension (40%) and tumors (20%). Fever was present in all the cases (100%) and the most frequent imaging finding was lung consolidation. Half of the cases exhibited hyponatremia, 40% of them had leukocytosis, and 50% of the patients presented elevated procalcitonin levels, as well as elevated levels of transaminases. In total, 2 patients (20%) required non-invasive oxygen support. All the cases presented a positive urinary antigen test for Legionella pneumophila serogroup 1. A total of 9 patients (90%) received levofloxacin-based therapy for a mean duration of 17.7 days. All the cases described herein were successfully discharged without any complications. On the whole, the present study demonstrates that a prompt clinical diagnosis along with early testing and treatment represent the cornerstone for positive outcomes in patients affected by Legionnaire's disease.