# Legionella pneumonia: A Case of Fever Prolonged for 10 Days

## TL;DR

A patient with a 10-day fever was diagnosed with Legionella pneumonia after initial treatment failed, showing the importance of broad testing and re-evaluation.

## Contribution

Highlights the clinical value of Legionella antigen testing and re-evaluation in non-responsive pneumonia cases.

## Key findings

- The patient's condition did not improve with initial empiric antibiotics for community-acquired pneumonia.
- Legionella antigen testing on hospital day four confirmed Legionella pneumonia.
- Tailoring antibiotics after testing led to significant clinical improvement.

## Abstract

Legionnaires’ disease is a potentially severe type of pneumonia most often caused by the organism Legionella pneumophila. Exposure to this bacterial pathogen typically happens in the community but may also occur in the hospital setting. This report describes the case of a patient who presented due to 10 days of fever, shortness of breath, and diarrhea, with initial imaging demonstrating multifocal pneumonia. The patient was appropriately started on empiric antibiotics for community-acquired pneumonia and admitted to the medicine floor. The patient showed no meaningful improvement in his initial hospital course on empiric antibiotics with continued oxygen requirements. Meanwhile, urine Legionella antigen testing returned positive on hospital day four, and after tailoring antibiotics accordingly, the patient's clinical status improved significantly. This case report highlights the efficacy of broad testing in the initial admission and the need for constant re-evaluation in the context of a patient not improving with appropriate therapy.