A Case of Pasteurella multocida Bacteremia in an Infant

We describe an uncommon case of a six-week-old male infant with Pasteurella multocida bacteremia. He presented to a tertiary care pediatric hospital emergency department (ED) in the American southeast (Arkansas, USA) with a new onset of fever and decreased oral (PO) intake. On exam, he was irritable, febrile, and tachycardic with no significant findings. Infectious workup was initially remarkable for an elevated procalcitonin of 7.25 ng/mL (reference range: 0.00-0.10 ng/mL) and a low white blood cell count of 3.2 K/cmm (reference range: 5.0-19.5 K/cmm). He was admitted and treated empirically with intravenous (IV) vancomycin, IV ceftriaxone, and IV acyclovir at meningitic dosing for possible sepsis and meningitis. A blood culture grew gram-negative rods, identified as P. multocida, while we were unable to interpret a bloody cerebrospinal fluid sample. Once beta-lactamase testing resulted negative, the patient completed a 14-day course of therapy with continuous IV penicillin per infectious disease recommendations. With antibiotics, pain management, and hydration, the patient improved clinically and was discharged home. Upon further questioning, parents reported that the patient was licked in the face by their pet cat but denied bites or scratches. In conclusion, P. multocida is an uncommon but reported cause of bacteremia and meningitis in infants. Exposure to dogs and cats is the leading risk factor; however, a bite wound or injury is not necessary for infection. This case demonstrates the high degree of clinical suspicion required to identify early presentations of P. multocida bacteremia and the importance for parents to be informed about the risk of infection and limit contact with pets during the first few months of life to prevent infection.