Prevalence of Positive Blood Cultures in the Emergency Department of a Tertiary Hospital: A Retrospective Single-Centre Study

Abstract

Background: Blood cultures (BCs) are frequently ordered during the course of investigation in emergency departments (EDs). However, there are few studies examining the clinical value of BCs and the prevalence of positive BCs in the adult ED.

Methods: This was a retrospective study conducted by reviewing patient charts to obtain all BCs collected in our ED over the course of one year. Out of 214,566 ED visits over the period from 1 July 2021 to 30 June 2022, a total of 1034 blood cultures were collected. The study was conducted in the ED of a teaching hospital in Taif, Makkah Region, Saudi Arabia, that has 500 beds for adults.

Results: The most commonly isolated organisms were Staphylococcus hominis (19.8%), Staphylococcus epidermidis (14.1%), Escherichia coli (9%), Klebsiella pneumoniae (8%), Staphylococcus capitis (7.3%), and Staphylococcus aureus (5.6%). Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa were isolated from 3.4% and 1.1% of positive blood cultures, respectively. In the context of antimicrobial sensitivity, the organisms isolated from positive BCs in this study showed the highest sensitivity to vancomycin (57.6%). This was followed by levofloxacin (48.6%), linezolid (48%), gentamycin (41.8%), amoxicillin clavulanate (39.5%), and clindamycin (39%). The highest prevalence of antimicrobial resistance was to ampicillin (42.4%). Resistance to clindamycin, azithromycin, piperacillin-tazobactam, and imipenem was 22%, 8.5%, 3.4% and 0.6%, respectively.

Conclusion: The prevalence of positive blood cultures in the ED of this tertiary hospital was high. The most commonly isolated organisms were Staphylococcus hominis, Staphylococcus epidermidis, Escherichia coli, and Klebsiella pneumoniae. Vancomycin elicited the highest antimicrobial sensitivity, followed by levofloxacin.