[Meningitis after a superficial dog bite]

Abstract

A 63-year-old healthy man developed acute meningitis. A Gram-stain of the cerebrospinal fluid showed Gram-negative rods, which grew slowly. They were identified by 16S ribosomal RNA sequence-analysis as Capnocytophaga canimorsus, an oral commensal found in various animal species including dogs. Upon further questioning, the patient mentioned a superficial dog bite. Using fluorescence-in situ-hybridisation with specific DNA probes, C. canimorsus cells were detected in a gingiva swab from his dog. The strains isolated from the patient and his dog were identical. The patient made a quick recovery following therapy with cefotaxime. Infections with C. canimorsus are associated with immune suppression (especially splenectomy or alcohol abuse), yet 40% of the patients have no predisposing conditions. Documented infections concern mainly sepsis or meningitis, with a mortality of approximately 30%. Due to its fastidious growth, C. canimorsus may be missed in standard culture methods. Therefore, in each case of unexplained sepsis or meningitis contact with animals should be enquired about.