Pasteurella multocida Infection of an Aortic Endograft: A Rare Zoonotic Complication

Pasteurella multocida is a zoonotic, encapsulated, and gram-negative coccobacillus frequently implicated in soft tissue infections following animal bites, particularly dogs and cats. Invasive infections, including bacteremia and endovascular involvement, are rare and typically occur in immunocompromised or elderly individuals. Vascular graft infections due to P. multocida are rare, with limited cases reported in the literature. We report the case of an 87-year-old man with a history of abdominal aortic aneurysm repair who presented with acute confusion, weakness, and dyspnea. Initial workup revealed leukocytosis, right lower lobe consolidation, and bacteremia with P. multocida. Further history uncovered a recent dog bite to the hand. Given the patient's vascular history, CT angiography was obtained revealing inflammatory changes surrounding the aortic graft, concerning for infectious aortitis. Due to the patient's advanced age and comorbidities, surgical intervention was deferred. He was treated with a four-week course of intravenous ceftriaxone followed by chronic oral doxycycline. Serial imaging with CT angiography over 18 months demonstrated clinical and radiographic stability, and suppressive antibiotic therapy was eventually discontinued without recurrence. This case highlights a rare but serious complication of P. multocida bacteremia involving vascular graft infection. In select patients with high surgical risk, long-term suppressive antibiotic therapy may offer a viable alternative to surgical intervention. Clinicians should maintain a high index of suspicion for endovascular infection in bacteremic patients with prosthetic vascular materials and recent animal exposure, even in the absence of overt localizing symptoms.