Remote regions, rapid recognition: performance and timeliness of BIOFIRE FilmArray BCID2 for diagnosing bloodstream infection in remote northern Australia

ABSTRACT Bloodstream infection is a time-critical diagnosis; however, the vast geographic distances in rural and remote locations lead to prolonged specimen transport times, which can impact the timeliness and quality of results. In this retrospective observational study, we evaluated the performance and timeliness of the BIOFIRE FilmArray Blood Culture Identification 2 (BCID2) nucleic acid amplification test conducted on positive blood culture broth fluid in two very remote hospital laboratories in the Northern Territory, Australia, and compared the results to conventional testing done in central laboratories in the laboratory network. We reviewed 343 blood cultures, from which 366 organisms were identified, collected between January 2021 and August 2024. In 207/228 (90.8%) blood cultures with at least one pathogen, the clinically significant organism(s) were detected by BCID2. Concordance between BCID2 and conventional identification methods for organisms on the BCID2 panel was 98.3% (95% confidence interval 96.1%–99.4%). Seventy-four organisms isolated had no BCID2 target; of these, 21 were pathogens, 15 of which were Burkholderia pseudomallei . A total of 126 organisms were considered contaminants; 71 (56%) of these were detected by BCID2. Importantly, BCID2 detections preceded conventional identification results by a median of 2.8 days (interquartile range 2.0–3.1 days). The BCID2 panel performed well in the hands of general scientists and substantially improved the timeliness of bloodstream pathogen identification in our setting. The need for additional targets, including B. pseudomallei and common contaminants, was identified. IMPORTANCE Bloodstream infection is a life-threatening condition requiring urgent treatment, and blood cultures are the mainstay of diagnosis. Timely incubation and processing of blood cultures maximize yield and clinical utility; however, prolonged specimen transport times in rural areas can impact the quality of results. We investigated the performance and timeliness of a rapid multiplex nucleic acid amplification test (the Blood Culture Identification 2 BCID2 panel) for detection of bacteria and yeasts in positive blood culture broth fluid in two small remote Australian hospital laboratories. Formal organism identification and susceptibility testing were subsequently conducted in larger, central laboratories. We found that the BCID2 panel detected the clinically significant organism(s) in 90.8% of blood cultures with at least one pathogen, with 98.3% concordance between BCID2 and conventional identification methods for organisms on the panel. BCID2 detections preceded conventional identification by a median of 2.8 days. The assay substantially improved the timeliness of bloodstream pathogen identification in the two remote regions.