A Case of Legionnaires' Disease in 70-Year-Old Patient: Delayed Diagnosis After Exposure to Contaminated Hotel Shower

Legionellosis, an acute infectious disease, often manifests as Legionnaires' disease with severe pneumonia. Transmission occurs via inhalation of Legionella-contaminated aerosols generated by contaminated water systems, with increased susceptibility in older adults, immunocompromised individuals, and those with comorbidities. Standard antibiotics for community-acquired pneumonia, such as β-lactams and aminoglycosides, are ineffective against Legionella due to its intracellular nature, highlighting the need for prompt and accurate diagnosis. In this study, we report a case of a 70-year-old woman presenting to the Emergency Department with weakness, cough, fever, palpitations, and nausea. Initially admitted to the Cardiology department for heart rhythm disorders, subsequent chest X-ray revealed bilateral pneumonia. Empiric antibiotic therapy with cephalosporins and monobactams was initiated but yielded no clinical improvement. As her condition deteriorated with signs of multi-organ involvement, she was transferred to the intensive care unit.PCR testing confirmed Legionella pneumophila, and targeted antibiotic therapy was initiated, resulting in the progressive improvement of the patient's condition. This case underscores the importance of considering Legionella in patients with epidemiological data of exposure to a potential contaminated environment, particularly patients with unspecific and various symptoms but present clinical data indicative of lung involvement. Early diagnosis and appropriate treatment are essential to prevent short-term and long-term complications and improve outcomes