(O-T2) Investigating the Efficacy of Rapid Molecular Assays in the Diagnosis of Bloodstream Infections

Objectives: The purpose of this systematic review and meta-analysis is to evaluate the diagnostic accuracy of different commercially available rapid molecular assays in the diagnosis of bloodstream infections.

Background: Sepsis is a life-threatening condition, characterized by a dysregulated systemic host response to infection. Early management with adequate antimicrobials has been shown to be associated with improved outcomes. The ’gold standard’ blood culture techniques in the diagnosis of bloodstream infections, however, have long turnaround times. To address that problem, rapid molecular assays have been developed. Methods requiring whole blood samples allow earlier pathogen detection and identification, compared to methods performed on positive blood culture samples, therefore even shorter turnaround time can be achieved.

Methods: A comprehensive search strategy was developed to identify studies that compared rapid molecular assays to blood culture techniques in patients with suspected or documented bloodstream infections. The systematic search was conducted in four databases: MEDLINE, Cochrane Trials, Web of Science and Embase, up to 10 January 2023. All eligible studies investigating the diagnostic accuracy of rapid molecular assays compared to blood cultures in patients with presumed or documented bloodstream infections were included. Pooled sensitivity and specificity were calculated and visualized on a two-dimensional plot.

Results: Preliminary results:
The systematic search resulted in 55159 records. After duplicate removal and title-abstract selection of 39037 articles, 709 eligible articles were identified, 15 of which we extracted data for preliminary data synthesis for one commercially available device. Using rapid molecular tests in the detection and identification of pathogens compared to blood culture showed a sensitivity of 67% [95% CI] = 0.57-0.76) and a specificity of 83% [95% CI] = 0.77-0.87) respectively. We found significant heterogeneity among the included articles (sensitivity: I2 = 83%, p < 0.01; specificity: I2 = 98%, p < 0.01). The reasons for this could be the heterogeneous population or the different indications of performing the rapid test in individual studies.

Conclusions: Preliminary conclusions:
Rapid diagnostic tests appear to have higher specificity than sensitivity. Based on the evidence presented here, it remains difficult to make recommendations about the clinical utility of rapid molecular assays in the setting of suspected or documented bloodstream infections.

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Funding (Optional): No funding