Comparative evaluation of the role of single and multiple blood specimens in the outcome of blood cultures using BacT/ALERT 3D (automated) blood culture system in a tertiary care hospital

Abstract

Introduction: Bloodstream infection (BSI) is a leading cause of mortality in critically ill patients. The mortality directly attributable to BSI has been estimated to be around 16% and 40% in general hospital population and Intensive Care Unit (ICU) population, respectively. The detection rate of these infections increases with the number of blood samples obtained for culture. The newer continuous monitoring automated blood culture systems with enhanced culture media show increased yield and sensitivity. Hence, we aimed at studying the role of single and multiple blood specimens from different sites at the same time in the outcome of automated blood culture system. Materials and Methods and Results: A total of 1054 blood culture sets were analyzed over 1 year, the sensitivity of one, two, and three samples in a set was found to be 85.67%, 96.59%, and 100%, respectively, which showed a statistically significant difference (P < 0.0001). Similar findings were seen in few more studies, however, among individual organisms in contrast to other studies, the isolation rates of Gram-positive bacteria were less than that of Gram-negative Bacilli with one (or first) sample in a blood culture set. In our study, despite using BacT/ALERT three-dimensional continuous culture monitoring system with FAN plus culture bottles, 15% of positive cultures would have been missed if only a single sample was collected in a blood culture set. Conclusion: The variables like the volume of blood and number of samples collected from different sites still play a major role in the outcome of these automated blood culture systems.

Three years Retrospective Analysis of Distribution and Antimicrobial Resistance Profiles of Isolates from Culture-positive Clinical Specimens at Felege Hiwot Comprehensive Specialized Hospital in northwestern Ethiopia

“…About 2489 isolates were identi ed. The reason why the isolates exceeded the number of patients is that repeated blood specimen collection from a single patient is mandatory to increase the probability of isolate detection and to ensure that the isolate is not contaminant (12,13).…”

Optimizing the number of blood cultures for lower and middle income countries: a large scale study in a public sector tertiary care teaching hospital of Southern India

“…This observation was seconded by several other studies in the literature. 6,7,12,21 The frequency distribution of pathogens (detection rate) isolated when collected in multiple sets was evaluated (Table 4). Out of all organisms isolated during the study period, only minor proportion (42-45%) were isolated from the BC episodes received with one BC bottle, as compared to the BC episodes received with ≤1 set (83-85%) and ≤2 sets (~98%) with a net gain of pathogen detection of about ~40% and ~13% when one set is collected compared to single bottle and 2 nd set is added to 1 st set BC respectively.…”

“…The relevant data collected were entered in Microsoft Excel and statistical analyses were performed with IBM SPSS Statistics V22.0 software. 12 The parameters used for the comparison of BC performance when collected in single bottle and multiple samples (1, 2 and 3 sets) have been defined in Table 1. The comparison of cumulative positivity rate, pathogen isolation rate, and pathogen detection rate between the episodes collected in single and multiple sets was carried out by using Kruskal-Wallis test (nonparametric).…”

“…The comparison of cumulative positivity rate, pathogen isolation rate, and pathogen detection rate between the episodes collected in single and multiple sets was carried out by using Kruskal-Wallis test (nonparametric). 12 Values of p <0.05 were considered as statistically significant. The agreement between increase in pathogen isolation rate and increase in contamination rate has been analysed by using Cohen's kappa statistics.…”

Trends in Bacterial Blood Culture Isolates and Resistance in Children in Two Microbiologic Eras from a Tertiary Health Facility in North East Nigeria

“…In these settings, the conventional/ manual culture methods remain the dominant systems while the automated blood culture systems have become the standard in high-income countries (HICs), and are relatively expensive and not universally available for implementation in most LMICs where [7] [8] [9] implementing automated microbiologic systems is feasible [7] [10]. Several reports [11] [12] [13] in LMIC showed that these systems show better performance than manual systems in terms of yield, sensitivity and especially speed of growth and overall turnaround time. Blood cultures are still indispensable for the diagnosis of BSIs however currently available molecular methods based on in situ hybridization-based methods, DNA microarray-based hybridization technology; nucleic acid amplification-based methods and combined methods [14] are a distant prospect for LMICs.…”