(546) Pasteurella multocida Empyema: Report of a Fatal Case

Introduction: Pasteurella multocida is a small, gram-negative facultative anaerobic commensal coccobacilli in the nasopharynx and gastrointestinal tract of animals. Medically, it is associated with dog and cat bites, scratches, and licks. P. multocida infections most commonly present as soft tissue, joint, or respiratory infections. On review of the literature, there are 25 reported cases of P. multocida isolated from pleural fluid cultures. We report a case of a 71-year-old female presenting with chest pain and shortness of breath due to an exudative loculated pleural effusion caused by P. multocida.

Description: A 71-year-old female with a past medical history of severe chronic obstructive pulmonary disease, chronic hypercapnic respiratory failure, tobacco use with 50 pack years, and hypertension presented with a chief complaint of shortness of breath and chest pain. Notably, patient did not have a history of cirrhosis. Chest radiograph was significant for a right sided pleural effusion which was subsequently drained with ultrasound guided thoracentesis. The effusion was found to be exudative by Light’s Criteria as well as loculated. P. multocida was isolated from cultures of pleural fluid and she was treated with intravenous ampicillin-sulbactam. Patient endorsed having one cat at home, with no history of bites, scratches, or sharing food. Despite antibiotic therapy and pleural fluid drainage, the patient’s respiratory status continued to worsen requiring non-invasive ventilation, and the family elected to pursue comfort care measures.

Discussion: Most human infections caused by P. multocida are caused by direct contact by cat or dog bites. There have been cases of indirect transmission that have been documented, though are probably less common. There are no guidelines in management regarding invasive pulmonary infections caused by P. multocida. P. multocida is a rare cause of empyema with a high rate of mortality, up to 45%, and it is typically associated with patients in immunocompromised states, including hepatitis cirrhosis, hematologic cancers, and history of organ transplantation. P. multocida should be considered in diagnostic workup in patients with dogs or cats at home regardless of risk factors or history of bite or scratch.