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Background Evidence about the clinical impact of rapid diagnostic tests (RDTs) for the diagnosis of bloodstream infections is limited, and whether RDT are superior to conventional blood cultures (B Cs) embedded within antimicrobial stewardship programs (ASPs) is unknown. Methods We performed network meta-analyses using results from studies of patients with bloodstream infection with the aim of comparing the clinical impact of RDT (applied on positive BC broth or whole blood) to conventional BC, both assessed with and without ASP with respect to mortality, length of stay (LOS), and time to optimal therapy. Results Eighty-eight papers were selected, including 25 682 patient encounters. There was an appreciable amount of statistical heterogeneity within each meta-analysis. The network meta-analyses showed a significant reduction in mortality associated with the use of RDT + ASP versus BC alone (odds ratio [OR], 0.72; 95% confidence interval [CI],.59–.87) and with the use of RDT + ASP versus BC + ASP (OR, 0.78; 95% CI,.63–.96). No benefit in survival was found associated with the use of RDT alone nor with BC + ASP compared to BC alone. A reduction in LOS was associated with RDT + ASP versus BC alone (OR, 0.91; 95% CI,.84–.98) whereas no difference in LOS was shown between any other groups. A reduced time to optimal therapy was shown when RDT + ASP was compared to BC alone (−29 hours; 95% CI, −35 to −23), BC + ASP (−18 hours; 95% CI, −27 to −10), and to RDT alone (−12 hours; 95% CI, −20 to −3). Conclusions The use of RDT + ASP may lead to a survival benefit even when introduced in settings already adopting effective ASP in association with conventional BC. [ABSTRACT FROM AUTHOR]

A prompt diagnosis of bacteraemia and sepsis is essential. Markers to predict the risk of persistent bacteraemia and metastatic infection are lacking. SeptiCyte RAPID is a host response assay stratifying patients according to the risk of infectious vs sterile inflammation through a scoring system (SeptiScore). In this study we explore the association between SeptiScore and persistent bacteraemia as well as metastatic and persistent infection in the context of a proven bacteraemia episode. This is a prospective multicentre observational 14-month study on patients with proven bacteraemia caused by Staphylococcus aureus or Gram-negative bacilli. Samples for assessment by SeptiCyte were collected with paired blood cultures for 4 consecutive days after the index blood culture. We included 86 patients in the study, 40 with S. aureus and 46 with Gram-negative bacilli bacteraemia. SeptiScores over the follow-up were higher in patients with Gram-negative compared to S. aureus bacteraemia (median 6.4, IQR 5.5–7.4 vs 5.6 IQR 5.1–6.2, p = 0.002). Higher SeptiScores were found to be associated with positive blood cultures at follow-up (AUC = 0.86, 95%CI 0.68–1.00) and with a diagnosis of metastatic infection at day 1 and 2 of follow-up (AUC = 0.79, 95%CI 0.57–1.00 and AUC = 0.82, 95%CI 0.63–1.00 respectively) in the context of Gram-negative bacteraemia while no association between SeptiScore and the outcomes of interest was observed in S. aureus bacteraemia. Mixed models confirmed the association of SeptiScore with positive blood cultures at follow-up (p = 0.04) and metastatic infection (p = 0.03) in the context of Gram-negative bacteraemia but not S. aureus bacteraemia after adjusting for confounders. SeptiScores differ in the follow-up of S. aureus and Gram-negative bacteraemia. In the setting of Gram-negative bacteraemia SeptiScore demonstrated a good negative predictive value for the outcomes of interest and might help rule out the persistence of infection defined as metastatic spread, lack of source control or persistent bacteraemia. [ABSTRACT FROM AUTHOR]

Background Persistent Staphylococcus aureus bacteremia is associated with metastatic infection and adverse outcomes, whereas gram-negative bacteremia is normally transient and shorter course therapy is increasingly advocated for affected patients. Whether the prolonged detection of pathogen DNA in blood by culture-independent systems could have prognostic value and guide management decisions is unknown. Methods We performed a multicenter, prospective, observational study on 102 patients with bloodstream infection (BSI) to compare time to bloodstream clearance according to T2 magnetic resonance and blood cultures over a 4-day follow-up. We also explored the association between duration of detectable pathogens according to T2 magnetic resonance (magnetic resonance–DNAemia [MR-DNAemia]) and clinical outcomes. Results Time to bloodstream clearance according to T2 magnetic resonance was significantly longer than blood culture clearance (HR,.54; 95% CI,.39–.75) and did not differ according to the causative pathogen (P =.5). Each additional day of MR-DNAemia increased the odds of persistent infection (defined as metastatic infection or delayed source control) both in the overall population (OR, 1.98; 95% CI, 1.45–2.70) and in S. aureus (OR, 1.92; 95% CI, 1.12–3.29) and gram-negative bacteremia (OR, 2.21; 95% CI, 1.35–3.60). MR-DNAemia duration was also associated with no improvement in Sequential Organ Failure Assessment score at day 7 from infection onset (OR, 1.76; 95% CI, 1.21–2.56). Conclusions T2 magnetic resonance may help diagnose BSI in patients on antimicrobials with negative blood cultures as well as to identify patients with metastatic infection, source control failure, or adverse short-term outcome. Future studies may inform its usefulness within the setting of antimicrobial stewardship programs. [ABSTRACT FROM AUTHOR]

Early etiological diagnosis and characterization of host response to infection are becoming central in sepsis recognition and management. Still, limitations in conventional diagnosis and patient stratification contribute to the high mortality rates among septic patients, despite new antimicrobials and resuscitation agents. Novel microbiological techniques and omics analyses have led to the development of several tests that are now commercially available or in the pipeline as rapid diagnostic tools. We first reviewed emerging assays for the etiological diagnosis of sepsis starting directly from whole blood, assays based on target-specific polymerase chain reaction or metagenomics. We then investigated results of different omics approaches for both bedside diagnosis of immune dysfunction and detection of patient "signatures" associated with different clinical outcomes or potential response to individualized therapies. Finally, we considered how these novel laboratory tools might be translated into clinical practice, noting that they perform best when integrated within antimicrobial stewardship programs. [ABSTRACT FROM AUTHOR]