Unique Presentation of a Ubiquitous Organism: Capnocytophaga canimorsus Meningitis With Pneumocephalus

Capnocytophaga canimorsus is a bacterium commonly found in the oral cavities of cats and dogs. Infections are particularly common in immunocompromised patients who have been exposed to bites or come in contact with saliva from these animals. The manifestations of infection include bacteremia, fever, and, rarely, meningitis. Diagnosis is challenging given the bacteria has slow growth on culture media. The organism is susceptible to beta-lactam antibiotics, with higher-generation cephalosporins recommended for treating meningitis. We present a case of a 74-year-old woman with altered mental status and no signs of immunosuppression. She was diagnosed with meningitis caused by Capnocytophaga, with an intriguing finding of pneumocephalus, which is a rare occurrence as per literature review.