Background: The mortality and morbidity attributable to bacterial sepsis can be mitigated by timely, appropriate antimicrobial therapy; determination of what is ‘appropriate’ is dependent on pathogen identification and susceptibility. In resource-limited settings, manual blood culture systems are often utilized, followed by traditional manual microbial identification methods, which often greatly delays definitive results. Novel molecular assays, such as the BIOFIRE® FILMARRAY® BCID panel (bioMérieux, France), can identify pathogens present in culture almost immediately, potentially facilitating earlier initiation of optimal antibiotic treatment. The objective of this study was to explore the use of the BIOFIRE® FILMARRAY® BCID panel at Princess Marina Hospital (PMH), a tertiary care centre in Botswana, as an add-on to the standard processing of positive blood cultures.
Methods: Positive blood cultures from PMH inpatients, incubated using the manual Oxoid Signal system (Thermo Fisher, UK), were randomized 1:1 to standard PMH microbiologic processing (control arm) or standard processing plus BIOFIRE® FILMARRAY® BCID testing (intervention arm). The results of both were compared to the MicroScan WalkAway (Siemens, USA) automated system at a separate, accredited, hospital. If the BIOFIRE® FILMARRAY® BCID identified a pathogen, specific antimicrobial(s) were also recommended to the clinical team.
Results: Between May 2018-Nov 2019, 279 participants were enrolled; the case-fatality rate in these inpatients with bacteraemia was 20%. BIOFIRE® FILMARRAY® BCID results were available on the day of enrolment, with a median time-to-result of 4.8 hours (IQR 3.9-6.8h); standard testing results were available at a median of 55 h (IQR 51-66h). 54% of cultures grew isolates judged to be contaminants. In the intervention arm, there were 15 specimens (5%) that were misidentified only by standard processing, 2 (0.7%) that were misidentified only by BIOFIRE® FILMARRAY® BCID, and 2 (0.7%) that were misidentified by both BIOFIRE® FILMARRAY® BCID and standard workup. 8 specimens (3%) tested by BIOFIRE® FILMARRAY® BCID grew isolates that were not targeted by the panel, but only 2 (0.7%) of these were pathogenic (Burkholderia cepacia, Aeromonas caviae); both of these were misidentified by standard PMH testing.
Conclusions: In a referral hospital in a resource-limited setting, BIOFIRE® FILMARRAY® BCID testing provided identifications much more rapidly and more accurately than standard microbiologic processing.