Multiplex PCR System for Rapid Detection of Pathogens in Patients with Presumed Sepsis - A Systemic Review and Meta-Analysis

Background: Blood culture is viewed as the golden standard for the diagnosis of sepsis but suffers from low sensitivity and long turnaround time. LightCycler SeptiFast (LC-SF) is a real-time multiplex polymerase chain reaction test able to detect 25 common pathogens responsible for bloodstream infections within hours. We aim to assess the accuracy of LC-SF by systematically reviewing the published studies. Method: Related literature on Medline, Embase, and Cochrane databases was searched up to October 2012 for studies utilizing LC-SF to diagnose suspected sepsis and that provided sufficient data to construct two-by-two tables. Results: A total of 34 studies enrolling 6012 patients of suspected sepsis were included. The overall sensitivity and specificity for LC-SF to detect bacteremia or fungemia was 0.75 (95% CI: 0.65-0.83) and 0.92 (95% CI: 0.90-0.95), respectively. LC-SF had a high positive likelihood ratio (10.10) and a moderate negative likelihood ratio (0.27). Specifically, LC-SF had a sensitivity of 0.80 (95% CI: 0.70-0.88) and a specificity of 0.95(95% CI: 0.93-0.97) for the bacteremia outcome, and a sensitivity of 0.61 (95% CI: 0.48-0.72) and a specificity of 0.99 (95% CI: 0.99-0.99) for the fungemia outcome. High heterogeneity was found in the bacteremia outcome subgroup but not in the fungemia outcome subgroup. Conclusion: LC-SF is of high rule-in value for early detection of septic patients. In a population with low pretest probability, LC-SF test can still provide valuable information for ruling out bacteremia or fungemia.