Decreasing the use of anaerobic culture bottles in selected febrile patients - Is it reasonable?

Background: Two sets of blood cultures are routinely obtained from febrile patients in the medical wards. The purpose of the present study was to evaluate the distribution of the aerobic versus anaerobic isolates in such patients and to examine the rationale of reducing the number of anaerobic culture bottles in selected patients. Methods: A retrospective analysis was performed of all febrile patients admitted to medical wards during 1998. Febrile patients from whom at least two sets of blood cultures were drawn and who had a bacterial isolation in at least one bottle were included. Results: A total of 317 patients were included in the analysis. Some 98.5% of all isolates were aerobic pathogens. Only 1.5% of all isolates (5 / 317) included obligatory anaerobes. The rate of isolation in a single anaerobic bottle was 8.5%. Analysis of the available files of patients with a single anaerobic positive bottle demonstrated that an adequate antibacterial agent was administered empirically in most of the cases (93%). Conclusions: We conclude that in carefully selected medical patients suspected of having an infectious disease, it is reasonable to obtain one anaerobic and two aerobic bottles rather than two full sets. Such an approach is clinically safe and will cut expenses on culture bottles and laboratory staff work. This approach should be examined in a prospective, randomized study.