Case Presentation: Pasteurella multocida is a classic infectious agent associated with dog and cat bits, with infections more commonly identified in the elderly, very young or immunocompromised. The proportion of American households with pets is increasing which in specific populations has been associated with health benefits, but little data exists towards risks.A 73-year-old female with a history of anemia, deep vein thrombosis and ovarian cancer initially presented to an outpatient oncology surveillance follow-up complaining of sore throat, dry cough, and fatigue. While in office, the patient had a throat swab taken and blood cultures collected. When blood cultures returned positive the next day, the patient was instructed to report to the emergency department. She was found to be febrile, with a temperature of 100.7 ° Fahrenheit. Physical exam demonstrated right sided neck fullness and cervical lymphadenopathy. Computed tomography of patient’s neck and soft tissue revealed soft tissue stranding surrounding the upper trachea and extending into adjacent subcutaneous fat. Inflammatory changes extended superiorly to the level of the larynx consistent with tracheitis and laryngitis with mild narrowing of the airway. Standard chest radiography was also done without any acute changes observed. Laboratory evaluation was unremarkable except for gram-negative rods on gram stains of both throat and blood cultures collected outpatient. She was initially started on empiric antibiotics. Both throat and blood cultures grew Pasteurella multocida. With the growth of this organism, questions were raised about pets in patient’s home. Patient informed that she lived with a dog, while there were no recent scratches or bites that she recalled, she admitted that at times, her dog would lick her face. Throat cultures later reported light growth of Pseudomonas aeruginosa in addition to Pasteurella multocida. Antibiotic coverage was changed to piperacillin/tazobactam 3.375g IV every 6 hours. Repeat blood cultures were drawn inpatient with no pathogens identified. She was discharged home with a fourteen day continuous infusion via her chemotherapy port for Pasteurella multocida bacteremia and laryngitis. On follow up in an outpatient infectious disease clinic, repeat cultures were without growth.
Discussion: While Pasteurella multocida infections are common in a variety of animals and are well documented members of domesticated animals’ microflora, they most commonly cause skin and soft tissue infections in humans. Rare cases, usually in the setting of asplenia or other significant immunocompromised state, can lead to devastating septicemia. This patient represents a unique case of bacteremia and laryngitis caused by Pasteurella multocida. While she was not actively undergoing chemotherapy (her last cycle of doxorubicin was a year ago) she likely remained more vulnerable to infection than an average immunocompetent host. The most likely route of infection seems to be from close contact with her dog rather than a bite or scratch. Patients who are at elevated risk for infections should be counseled on the risks and benefits of pet ownership and strategies to mitigate risk.
Conclusions: History taking remains key to the discovery of atypical infections and presentations. Without it, only the most stereotypical cases will be caught and treated appropriately. Empiric treatment for a bacterial pharyngitis could have proved disastrous for our patient, but a thought toward culture, and a unique history unraveled the case.