A cold-blooded culprit: Salmonella enterica subsp. arizonae pulmonary infection in an immunocompromised patient: a case report

Background Salmonella enterica subsp. arizonae is an uncommon zoonotic pathogen primarily associated with reptiles. While most infections are gastrointestinal, invasive infections such as bacteremia, osteomyelitis, meningitis, and septic arthritis have been reported, particularly in immunocompromised individuals. Pulmonary infections are exceedingly rare. Case Presentation A 66-year-old woman with rheumatoid arthritis on a TNF-α inhibitor presented with a two-week history of progressive cough and dyspnoea. She reported prolonged exposure to a pet snake. Sputum cultures confirmed S. enterica subsp. arizonae, with susceptibility to ciprofloxacin. Imaging revealed the right lower lobe infiltrates without cavitation. She was successfully treated with ciprofloxacin for two weeks, with resolution of symptoms. Conclusion This case highlights an uncommon presentation of Salmonella infection in an immunocompromised patient with bronchiectasis. With increasing exotic pet ownership, clinicians should maintain a high index of suspicion for S. arizonae in patients with known reptile exposure.