Capnocytophaga canimorsus infections in human: Review of the literature and cases report

Capnocytophaga canimorsus, formerly designated Dysgonic fermenter 2 (DF-2) was first described in 1976: it is a commensal bacterium of dogs and cats saliva, which can be transmitted to man by bite (54% of cases), scratch (8.5%), or mere exposure to animals (27%). We present a review of the clinical and microbiological characteristics of the Capnocytophaga canimorsus infections and 12 cases of infection in France. Over 100 cases of human infections have been reported, mainly septicemia in patients with diminished defences, due to splenectomy (33%), alcohol abuse (24%), immunosuppression (5%). However 40% of septicemia occur in patients with no predisposing conditions. Other infections are less frequent: meningitis, endocarditis, arthritis, pleural and localized eye infections. These infections range from mild to fulminating disease, with shock, respiratory distress, disseminated intravascular coagulation. Dermatological lesions (macular or maculopapular rash, purpura) or gangrene are common. This fastidious Gram-negative bacterium grows slowly on chocolate agar or on heart infusion agar with 5% rabbit blood incubated in 5% CO,. In spite of a great susceptibility of bacteria to antibiotics, the mortality is of 30%. Because of the severity of these infections, taking into account this organism in the management of bites is necessary, especially in patients with predisposing factors.