Severe Legionella Pneumophila Infection in an Immunocompetent Patient: A Success Story 300 Kilometers Away

The most significant outbreak of Legionella pneumophila, or Legionnaires' Disease, ever registered in Portugal occurred in 2014, and was considered one of the largest in European history. This relatively rare infection has a dire prognosis if not timely identified and correctly treated, presenting with a high lethality rate. We describe a case of infection by Legionella pneumophila in a previously healthy individual during an outbreak that originated 300 kilometers away from our hospital. The patient presented to the Emergency Department and after an initial assessment, was admitted to the Intensive Care Unit (ICU). He underwent supportive treatment with invasive mechanical ventilation and antibiotic therapy, having been discharged with functional improvement 21 days after admission. During follow-up, the patient presented well without residual clinical or radiological findings. Prompt management following established guidelines allowed for the appropriate treatment and a favorable prognosis. This case serves as a reminder that early management is important, healthy individuals without known risk factors may present with severe infection, and there is the possibility for individual cases of Legionellosis to present far from the outbreak source.