title: The detection of positive blood cultures by the BACTEC NR660. The clinical importance of four-day versus seven-day testing.
abstract: A total of 471 positive blood cultures obtained over a 3-month period were identified and evaluated for day of positivity by the BACTEC NR660. Of all positive blood cultures, 73% (344) were detected within the first 2 days, and 94% (441) were detected through day 4. The proportion of positive cultures detected at day 5 was significantly lower than that at day 4 (p less than 0.01). Patient chart review revealed that two of 30 isolates (0.4% of all positive isolates) identified on days 5-7 were considered clinically significant and would have been missed if cultures would not have been evaluated for seven days. Therefore, very limited additional patient benefit is derived after greater than 4 days of growth and detection by the BACTEC NR660.
authors.affiliation: Department of Medical Microbiology, Temple University, Philadelphia, Pennsylvania.
authors.forename: M R
authors.initials: MR
authors.lastname: Evans
authors.forename: A L
authors.initials: AL
authors.lastname: Truant
authors.forename: J
authors.initials: J
authors.lastname: Kostman
authors.forename: L
authors.initials: L
authors.lastname: Locke
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D016009:Chi-Square Distribution; D006801:Humans; D018805:Sepsis / Q000097:blood / Q000175:diagnosis*; D013997:Time Factors