Capnocytophaga species: infections in nonimmunocompromised and immunocompromised hosts

Retrospective review of isolates of Capnocytophaga, a genus of capnophilic gram-negative bacilli, referred to the Massachusetts State Laboratory Institute in Boston revealed 31 patients with infection due to Capnocytophaga, 16 in nonimmunocompromised hosts. These infections included empyema (three patients), lung abscess (one), sinusitis (one), conjunctivitis (three), subphrenic abscess (one), wound (three), osteomyelitis (one), and bacteremia (three). Two of the wound infections were closed-fist injuries involving bone or soft tissue. Capnocytophaga was frequently isolated as part of a polymicrobial infection with other oral flora. There was only one death in the nonimmunocompromised group. In contrast, of 15 immunocompromised patients with 16 episodes of bacteremia due to Capnocytophaga, 87% had leukopenia and 73% had significant oral pathology such as gingivitis, mucositis, or ulceration. Five immunocompromised patients died. Thus, Capnocytophaga species may cause disease in both nonimmunocompromised and immunocompromised hosts. Isolation of this organism should suggest an oral source for infection.