Anaerobic bacteremia in a general hospital: retrospective five-year analysis.

Anaerobic bacteremia (116 cases) represented 5.4% of the total cases of bacteremia in the Hospital Nuestra Señora de Covadonga of Oviedo, Spain, during a five-year period (1981-1985). Microbiologic data for all 116 cases and clinical data for 63 patients were analyzed. A total of 129 isolates were identified as gram-negative bacilli (45.7%), gram-positive bacilli (38.0%), gram-positive cocci (14.0%), and gram-negative cocci (2.3%). Bacteroides fragilis and Clostridium perfringens were the most frequently occurring species. Anaerobic polymicrobial infection was detected in 21 patients. The most relevant clinical features were fever (79%), metastatic abscesses (33%), anemia (27%), septic shock (25%), and disseminated intravascular coagulation (6%). The overall mortality rate was 25.4%, and the factors associated with a poor prognosis were age over 60 years, lack of adequate surgical treatment, severe underlying disease, metastatic foci, and polymicrobial and/or nosocomial infection.