PCR-ESI/MS for Molecular Diagnosis of Bloodstream Infections Directly from Blood Samples: a Systematic Review and Meta-Analysis

PCR-ESI/MS is a commercial molecular method that can identify bloodstream infection (BSI) pathogens directly from blood. Previous studies showed its sensitivity varied greatly. Its diagnostic accuracy has not been systematically evaluated yet, thus we aimed to assess its accuracy by systematic review and meta-analysis.Studies were searched on PubMed and Embase up to November 2017, for studies using PCR/ESI-MS to diagnose BSI directly from blood and providing sufficient data to construct two-by-two tables. Subgroup analysis and meta-regression were used to assess heterogeneity.A total of nine studies including 3,392 patients met the inclusion criteria. Their pooled sensitivity and specificity was 0.66 (95% CI: 0.57 - 0.74) and 0.84 (95% CI: 0.78 - 0.89), respectively. The positive and negative likelihood ratios were 4.2 (95% CI: 3.0 - 5.9) and 0.40 (95% CI: 0.31 - 0.50), respectively. The diagnostic odds ratio (DOR) was 10.61 (95% CI: 6.67 - 16.88). The area under the SROC was 0.82 (95% CI: 0.78 - 0.85). High heterogeneity was found. Subgroup analysis and meta-regression showed that regions, BSI prevalence, blood volume, and settings may cause heterogeneity.PCR-ESI/MS using blood specimens directly has the potential for early diagnosis of BSI, compared with blood culture. Its rule-in value is higher than rule-out value. Due to the heterogeneity of currently available studies, further high-quality studies are still needed.