Follow-up blood culture in Gram-negative bacteraemia
Purpose of review: The aim of this narrative review is to examine available evidence about the diagnostic yielding of the follow-up blood cultures (FU-BCs) in patients with Gram-negative bloodstream infection (GN-BSI), the predictors of persistent GN-BSI, and the impact of the performance of FU-BCs on patient management and clinical outcome.
Recent findings: The rate of persistent GN-BSI varies from 2.6% to 38.5%, with higher percentages in studies where FU-BCs were obtained from selected patients. Risk factors for persistent GN-BSI were analysed and prediction tools were proposed to guide physicians in the selection of patients. The impact of FU-BCs on patient management is still controversial as several authors have shown that this practice was associated with prolonged treatment duration and longer hospital stay. However, when adjusted for indication and survival bias, the performance of FU-BCs was a strong predictor of survival in large cohorts of hospitalized patients with GN-BSI. Favourable outcome seemed to be associated with higher rate of source control in GN-BSI patients managed with FU-BCs.
Summary: The practice of FU-BCs in patients with GN-BSI should be individualised balancing cost/benefit ratio. The use of risk scores could be useful in selecting patients for whom FU-BCs are appropriate.
Giannella M, Pascale R, Viale P. Follow-up blood culture in Gram-negative bacilli bacteraemia: for whom is follow-up blood culture useful? Curr Opin Infect Dis. 2022 Aug 4. doi: 10.1097/QCO.0000000000000865. Epub ahead of print. PMID: 35942855.