Diagnostic Accuracy of Molecular Methods for Detecting Bloodstream Infections: A Systematic Review and Meta-Analysis

Bloodstream infections (BSIs) are a major cause of morbidity and mortality worldwide and require rapid and accurate diagnosis to guide appropriate antimicrobial therapy. Conventional blood culture remains the gold standard for detecting bloodstream pathogens; however, it has several limitations including prolonged turnaround time and reduced sensitivity in patients receiving prior antibiotic therapy. In recent years, molecular diagnostic techniques such as polymerase chain reaction (PCR), multiplex PCR, digital PCR, and next-generation sequencing have emerged as promising tools for the rapid detection of bloodstream pathogens and antimicrobial resistance markers. This systematic review and meta-analysis aimed to evaluate the diagnostic accuracy of molecular methods for detecting bloodstream infections compared with conventional blood culture. A comprehensive search of PubMed, Scopus, Web of Science, and Embase databases was conducted to identify studies assessing molecular diagnostic assays for bloodstream infections. Eligible studies reporting sufficient data to calculate sensitivity and specificity were included. A total of 28 studies involving 6,742 patients were analyzed. The pooled sensitivity and specificity of molecular diagnostic methods were 0.88 (95% CI: 0.84–0.91) and 0.94 (95% CI: 0.91–0.96), respectively. Subgroup analysis indicated that multiplex PCR platforms demonstrated the highest sensitivity among evaluated techniques. Molecular assays also showed excellent performance in detecting antimicrobial resistance genes such as mecA and carbapenemase genes. These findings suggest that molecular diagnostics provide rapid and accurate detection of bloodstream pathogens and may significantly improve early diagnosis and antimicrobial stewardship. However, molecular methods should currently be used as complementary tools alongside conventional blood culture, which remains essential for antimicrobial susceptibility testing and detection of uncommon pathogens