Pasteurella multocida Septicemia in a Diabetic Patient

Abstract

INTRODUCTION: Pasteurellosis is a zoonosis caused by domestic animal bites or by direct exposure to their secretions. We present a case of P. multocida septicemia in a well controlled diabetic patient. CASE PRESENTATION: A 49 year-old man with well-controlled diabetes mellitus (HbA1c 5.5%), hypertension, chronic venous insufficiency presented with dizziness and fever for 3 days. He had worsening left lower extremity swelling with redness and warmth. He was febrile to 101.1 F with blood pressure 78/60 mm Hg and tachycardia of 132 beats/min. There was a 1 cm open wound on the left calf. He had leukocytosis (29.5x109/L with 19% band forms),elevated lactate level (9.1mmol/L) and acute kidney injury (creatinine 4.1 mg/dL). He was admitted to the ICU for septic shock and required norepinephrine even after adequate fluid resuscitation. Given a history of anaphylactic reaction to penicillin he was initially treated with vancomycin, levofloxacin and aztreonam. Blood cultures grew 4/4 bottles of Pasteurella multocida susceptible to levofloxacin. Vancomycin and aztreonam were discontinued. Follow up blood cultures were negative. He improved hemodynamically and was discharged home to complete a 14 day oral levofloxacin course. Since P.multocida infections are related to exposure to domestic animals, on further interrogation he reported having a dog. He ensured that the dog did not lick his legs but admitted to occasionally leaving his legs without bandages when sleeping. He likely contracted P.multocida from the dog licking his open leg wound. DISCUSSION: Pasteurella species exist as normal upper respiratory flora of domestic and wild animals. The pathogenesis of human P. multocida infections is divided into three groups related to the etiology of the infection. The commonest consist of local infections following animal trauma. The second group includes infections associated with atraumatic animal exposure. Respiratory infections are the most common, especially in patients with underlying chronic pulmonary disease. Respiratory infections result from airborne or vector contact. The third group of P.multocida infections includes those not associated with animal exposure which can result in systemic infections. Even in the absence of obvious animal exposure, it is believed that an animal reservoir is the major source. Severe forms of Pasteurella infection occur more frequently in immunocompromised patients. Although diabetes in our patient was well controlled, it may have played a role in the development of sepsis from P. multocida. CONCLUSIONS: Pasteurella septicemia should be suspected in immunocompromised patients with a history of direct animal exposure.