Isolation of Hafnia alvei from bronchoalveolar lavage of an immunocompetent host presenting with cavitating pneumonia: Contaminant or Causative?

Introduction: Hafnia alvei is a Gram-negative, facultative anaerobic bacillus that is most often found as an enteric commensal. It is seldom considered to be pathogenic in immunocompetent individuals.

Case report: We describe a case of a 23-year-old, previously healthy male, who presented to the emergency department with a two-day history of hemoptysis, mild dyspnea, pleuritic chest pain, fevers, and chills. Bloods revealed leukocytosis and elevated C-reactive protein. Chest X-ray and CT of the thorax revealed a cavitating lesion in the right upper lobe. He was commenced on empiric antibiotic treatment with amoxicillin/clavulanate and clarithromycin for community-acquired pneumonia in accordance with local guidelines. He subsequently underwent a bronchoscopy, and the bronchoalveolar lavage sample revealed a heavy growth of H. alvei. Despite the widely documented natural resistance of H. alvei to penicillin, the patient demonstrated complete resolution of his symptoms and initial raised inflammatory markers.

Conclusions: We present a case of community-acquired cavitary pneumonia in a previously healthy young adult with H. alvei isolated from bronchoalveolar lavage samples. Parallels are drawn between our case and other cases of H. alvei respiratory isolates in our discussion of its clinical significance.