Polymicrobial bacteremia in children. An 11-year experience.

The clinical records of all patients with blood cultures positive for a bacterial pathogen were retrospectively examined during an 11-year period to determine the rate of and clinical features associated with polymicrobial bacteremia. During this period, bacteria were isolated in 6302 blood cultures. Of these cultures, 38 instances (0.6%) of polymicrobial bacteremia occurred in 38 patients. In 37 patients (97%), an underlying condition was identified that was considered a predisposing factor for polymicrobial bacteremia--18 patients (42%) had lesions of the gastrointestinal tract, 13 patients (34%) had an indwelling central venous catheter, nine patients (24%) had a malignant neoplasm or were receiving chemotherapy, and nine patients (24%) had neutropenia. A total of 98 pathogenic organisms were isolated; 52 were gram-negative and 46 were gram-positive, and 18 patients (47%) had more than two organisms isolated. Polymicrobial bacteremia was usually clinically indistinguishable from monomicrobial septicemia. Overall mortality was 32%. Polymicrobial bacteremia continues to be a rare, but serious, infectious disease that usually affects children with underlying medical problems and is associated with a high rate of mortality.