Evaluation of blood culture epidemiology and efficiency in a large European teaching hospital

Abstract

BackgroundBlood cultures remain the gold standard for detecting bacteremia despite their limitations. The current practice of blood culture collection is still inefficient with low yields. Limited focus has been given to the association between timing of specimen collection at different time points during admission and their yield.MethodsWe carried out a retrospective observational study by analyzing all 3,890 sets of cultures collected from the 1,962 admitted patients over the seven-month period of this study. We compared the blood culture yield between the early group (≤24 hours after admission) and the late group (> 24 hours of admission). We also investigated the effect of prehospital oral antibiotics and pre-analytical time on the first cultures in the emergency department. Epidemiology and efficiency of blood cultures were studied for each medical specialty.ResultsIn total, 3,349(86.1%) blood cultures were negative and 541(13.9%) were positive for one or more microorganisms. After correcting for contamination, the overall yield was 290 (7.5%). The early group (n = 1,490) yielded significantly more true-positive cultures (10.1% versus 5.8%, P<0.001) than the late group (n = 2,400). The emergency department had a significantly higher yield than general wards, 11.2% versus 5.7% (p<0.001). Prehospital oral antibiotic use and pre-analytical time did not affect the yield of first cultures at the emergency department (p = 0.735 and 0.816 respectively). The number of tests needed to obtain one true-positive culture varied between departments, ranging from 7 to 45.ConclusionThis study showed that blood cultures are inefficient in detecting bacteremia. Cultures collected during 24 hours after admission yielded more positive results than those collected later. Significant variations in blood culture epidemiology and efficiency per specialty suggest that guidelines should be reevaluated. Future studies should aim at improving blood culture yield, implementing educational programs to reduce contamination and cost-effective application of modern molecular diagnostic technologies.

Clinical assessment of the utility of metagenomic next‐generation sequencing in pediatric patients of hematology department

“…Due to the use of broad‐spectrum antibiotics and prevalence of fastidious microorganisms, culture often fails to detect the culprit. Typically, the positive rate of blood culture is less than 10% 17 . In this study, culture was positive in 5.71% (4/70) of patients.…”

Antimicrobial resistance (AMR) at the community level

“…It is interesting to note that all the blood cultures from the rural site ( n = 19) that were ordered showed no growth and 72.22% of the blood cultures ( n = 72) sent from urban site also showed no growth. This could be due to multiple reasons which are well documented in the literature[ 13 ]: low yield of blood culture (including in sepsis), transport and collection issues.…”

Strategies for increasing diagnostic yield of community-onset bacteraemia within the emergency department: A retrospective study

“…One of the main criticisms for obtaining BCs in the ED is the low diagnostic yield. Hence, strategies to improve the diagnostic yield and studies aimed at improving BC yield, such as the implementation of educational programs based on proper BC collection, are warranted [38]. It has been reported that physicians overestimate the likelihood of bacteraemia for many of their patients [39–41].…”