Lack of clinical relevance in routine terminal subculturing of blood cultures

Abstract

The usefulness of performing final blind subcultures of previously negative blood cultures was evaluated over a 21 mo. period. From > 14,000 blood culture bottles blindly subcultured after 7 days of incubation, only 12 potentially significant organisms [bacteria] were found. The finding of these 12 organisms did not influence patient care since in 11 instances the same organism was already reported from prior positive bottles and in 1 instance the patient had already died. These results suggest that blind 7 day subcultures are of minimal value. Other factors that need to be considered before eliminating the final subculture are presented.