The great malaria problem: where is the light at the end of the tunnel?

Capnocytophaga canimorsus: an emerging cause of sepsis, meningitis, and post-splenectomy infection after dog bites

Newly named in 1989, Capnocytophaga canimorsus is a bacterial pathogen found in the saliva of healthy dogs and cats, and is transmitted to humans principally by dog bites. This review compiled all laboratory-confirmed cases, animal sources, and virulence attributes to describe its epidemiology, clinical features, and pathogenesis. An estimated 484 patients with a median age of 55 years were reported, two-thirds of which were male. The case-fatality rate was about 26%. Its clinical presentations included severe sepsis and fatal septic shock, gangrene of the digits or extremities, high-grade bacteremia, meningitis, endocarditis, and eye infections. Predispositions were prior splenectomy in 59 patients and alcoholism in 58 patients. Dog bites before illness occurred in 60%; additionally, in 27%, there were scratches, licking, or other contact with dogs or cats. Patients with meningitis showed more advanced ages, higher male preponderance, lower mortality, and longer incubation periods after dog bites than patients with sepsis (p < 0.05). Patients with prior splenectomy presented more frequently with high-grade bacteremia than patients with intact spleens (p < 0.05). The organism possesses virulence attributes of catalase and sialidase production, gliding motility, cytotoxin production, and resistance to killing by serum complement due to its unique lipopolysaccharide. Penicillin is the drug of choice, but some practitioners prefer third-generation cephalosporins or beta-lactamase inhibitor combinations. C. canimorsus has emerged as a leading cause of sepsis, particularly post-splenectomy sepsis, and meningitis after dog bites.

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% CO2. 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.