Blood culture pathways in UK hospitals: an exploratory survey

Timely blood culture (BC) processing is key for optimising antimicrobial therapy in bloodstream infections. However, variability in pre-analytical, analytical, and postanalytical workflows may limit the clinical benefits of rapid diagnostics.

We conducted a nationwide survey (1^st February, 2024-6^th February, 2025) of microbiology laboratories across England and Scotland to assess BC pathways, turnaround times for organism identification and antimicrobial susceptibility testing (AST), availability of rapid methods, operational hours, and result communication. Associations between workflow factors and turnaround times were evaluated using univariate analysis.

Thirty-one sites participated, including teaching (20/31 sites [64%]) and district general hospitals (11/31 sites [35%]). BCs were incubated and analysed on-site in 20 of 31 sites (65%), incubated on-site but analysed off-site in five of 31 sites (16%), and processed entirely off-site in six of 31 sites (19%). Ward-based incubators were rare (3/31, 10%). Incubation within 4 h was reported in 16 of 31 sites (52%) and was strongly associated with 24-h-a-day laboratory services (odds ratio [OR]: 10.0, 95% confidence interval [CI]: 0.99-100, P = 0.050). Rapid identification technique was available in 30 of 31 sites (97%), via matrix-assisted laser desorption/ionisation time-of-flight, and achieved results within 8 h of a BC flagging positive in 11 of 30 sites (37%). Sites performing both incubation and analysis off-site were more likely to provide identification within 8 h of positive BC (OR: 26.7, 95% CI: 2.24-317.1, P = 0.009). Rapid AST was available in eight of 31 sites (26%), but only one site achieved results within 8 h; no factors were significantly associated with AST results ≤24 h. Only 10 of 31 sites (32%) operated 24 h a day, and two of 31 sites (6%) routinely communicated identification results and one of 31 sites (3%) communicated AST results at all hours.

BC pathways across England and Scotland show significant variability, with most of the laboratories using rapid identification methods but limited access to rapid AST and operating hours under 12 h a day. Faster pre-analytical processing is linked to 24-h-a-day working laboratories and rapid identification to centralisation, but rapid AST capacity remains limited. Extending operational hours, optimising transport, and adopting rapid AST may improve BC workflows, shorten turnaround times, and support timely antimicrobial optimisation.