Transport time for blood culture bottles: underlying factors and its consequences

In the present study we investigated transport times for blood cultures from three tertiary-care hospitals to Karolinska University Laboratory and identified predictors of long transport times. Concomitantly, consequences of delayed incubation on total detection time (TDT) were analyzed by in vitro sepsis models. A total of 909 blood cultures were studied. The median (interquartile range) transport time was 9 (3–15) h. The hospital accommodating the microbiology laboratory had the shortest transport time compared to the other two hospitals (P < 0.0001). Samples taken between 16:00–24:00 had longer transport times compared to samples taken between 8:00–16:00 and 24:00–08:00 (P < 0.0001). In vitro experiments showed that TDT was longer for samples pre-incubated at room temperature (RT) for 19 h compared to the ones pre-incubated for 2 h or 9.5 h (P < 0.0001). In conclusion, off-site location, time of sampling and number of transports per day were related to, and predictors of transport time.