Three days of incubation may be sufficient for routine blood cultures withBacT/Alert FAN blood culture bottles

BacT/Alert FAN blood culture bottles have been shown to enhance the recover y of bacteria and yeast from blood compared with standard BacT/Alert bottle s. It is well established that standard BacT/Alert blood culture bottles re quire no more than 5 days of incubation for the detection of routine bacter ia and yeast. It is less clear, however, whether FAN bottles also routinely require 5 days of incubation. To address this question, we recently review ed the results of 17,887 blood culture sets collected in FAN blood culture bottles at Geisinger Medical Center. Of these cultures, 1,780 were positive for bacteria or yeast, yielding a total of 1,242 clinically significant is olates, The numbers of isolates recovered on days 1, 2, 3, 4, and 5 were as follows: (values in parentheses are percentages of total significant isola tes): 877 (71%), 269 (22%), 65 (5%), 18 (1%) and, 13 (1%), respectively. In total, 97.5% of all clinically significant isolates were detected in the f irst 3 days of incubation. Of the 31 significant isolates detected on day 4 or 5 of incubation, 17 were detected in concurrent blood cultures within t he first 3 days of incubation. Chart reviews were conducted for the 13 pati ents,vith the remaining 14 isolates detected on day 4 or 5 to determine whe ther therapy was changed due to this blood culture result. Therapy was chan ged for only 1 patient. These results suggest that it may not be necessary to routinely incubate FAN blood culture bottles for more than 3 days.