Capnocytophaga canimorsus: An Emerging Pathogen in Immunocompetent Patients-Experience from an Emergency Department

Capnocytophaga canimorsus is a bacterium of the normal oral flora of dogs and cats. Human infection is caused by animal bite but is rarely observed, mainly in immunocompromised patients. We present 2 cases of C. canimorsus infection that occurred in immunocompetent patients and caused multiorgan failure and in both cases severe neurologic involvement.

In the first case, we present a 69-year-old immunocompetent woman with septic shock derived from skin and soft tissue infection after a dog's bite. She developed ischemic necrosis evolving to gangrene of both forefeet and hands, infective aortic endocarditis, and neurologic involvement caused by large hemispheric hypodense lesions compatible with ischemic septical lesions. In the second case, we present a 65-year-old immunocompetent man with meningitis after a dog's bite. Despite antibiotic therapy, he developed neurologic clinical deterioration, with right sensitive hemisyndrome associated with lack of strength and motor skills of the right hand. Radiologic findings were consistent with the diagnosis of cerebritis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Clinicians should always be aware of this pathogen, both in immunocompromised and immunocompetent patients, and consider prophylactic antibiotics after exposure.