<i>Legionella</i> infection with renal and muscular complications: a clinical case with a focus on clinical aspects and imaging diagnostics

Legionellosis is a serious respiratory infection caused by the bacterium Legionella pneumophila, transmitted through the inhalation of contaminated aerosol. The most common form is pneumonia, but rare complications such as rhabdomyolysis and acute kidney injury (AKI) may occur, increasing both morbidity and mortality. These require early recognition and targeted treatment. A 54-year-old man with a history of chronic alcoholism presented to the Emergency Department with fever, diarrhea, and confusion. Vital signs were within normal limits, but laboratory tests revealed rhabdomyolysis and AKI with compensated metabolic acidosis. In the following days, renal function deteriorated, and muscle damage persisted. Chest computed tomography (CT) revealed bilateral pulmonary consolidations and pleural effusion, while brain CT showed chronic vascular leukoencephalopathy. The diagnosis of legionellosis was confirmed by a positive urinary antigen test for Legionella pneumophila serogroup 1. The patient began targeted antibiotic therapy with azithromycin and levofloxacin, combined with corticosteroids. Due to worsening renal function, he underwent hemodialysis. During hospitalization, clinical and laboratory improvements were observed, with recovery of renal function and resolution of rhabdomyolysis, although pulmonary lesions persisted. This case highlights the importance of considering legionellosis in cases of pneumonia complicated by rhabdomyolysis and AKI. Timely diagnosis and appropriate treatment are crucial to prevent severe complications and improve outcomes.