MBBS MedStar Health Georgetown University (Baltimore)
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Introduction: Legionella is the second most common cause of severe pneumonia in hospital after Streptococcus pneumoniae. Severe cases are known to present with respiratory symptoms accompanied with gastrointestinal and neurological manifestations.
Description: 62-year-old female with obstructive sleep apnea on CPAP, colon cancer in remission presented with the chief complaint of multiple episodes of diarrhea, nausea and vomiting for 2 days. This was accompanied by nonproductive cough and fatigue for 5 days. Initial physical examination revealed stable vitals, mild respiratory distress, crackles in the left mid and lower lobes. Labs were significant for leukocytosis and hyponatremia. Initial chest x-ray showed bilateral airspace opacities, more prominent in the right lower lobe. Chest CT showed right lower lobe consolidation along with reactive right hilar and subcarinal lymphadenopathy. During hospital course, she grew more hypoxic over the first day and on the second day needed to be intubated for respiratory distress and hypoxia. Patient also developed septic shock requiring pressors and subsequently acute kidney injury requiring temporary CRRT. She was initially treated with azithromycin and ceftriaxone, however after clinical deterioration, antibiotics were broadened first to Zosyn and then to meropenem along with azithromycin. Urine Legionella antigen was positive and pneumonia PCR panel was positive for Legionella pneumophila. Patient was treated with azithromycin for 14 days. She was extubated on day 8 in ICU, but needed to be reintubated, later requiring tracheostomy on day 10 in ICU. Later, patient improved on antibiotics and supportive treatment being able to be weaned off on tracheal collar. She was discharged to rehab facility with tracheostomy on trach collar and speaking valve.
Discussion: Early initiation of Legionella specific antimicrobial therapy has been shown to be predictors of mortality. Patients may require ICU admission and major organ support, but with appropriate antibiotic therapy they have a rapid turnaround, with worse outcomes in immunocompromised individuals. In advanced centers, supportive treatment with VV ECMO has shown major benefit, especially given the highly aerophilic characteristics of the causative pathogen.
