Comparative Diagnostic Accuracy of Xpert Carba-R and NG-Test CARBA-5 for Carbapenemase Detection in Carbapenem-Resistant Enterobacterales: A Systematic Review and Meta-Analysis.

BACKGROUND

Carbapenem-resistant Enterobacterales (CRE) pose a critical public health threat, with carbapenemase-producing organisms driving treatment failures and nosocomial outbreaks. Xpert Carba-R (PCR-based) and NG-Test CARBA-5 (immunochromatographic) are widely adopted rapid diagnostics, yet no meta-analysis has compared their performance.

METHODS

We conducted a systematic review and meta-analysis following PRISMA 2020 guidelines, searching PubMed, EMBASE, and Cochrane Library (January 2016-December 2024). Two independent reviewers screened studies, extracted data, and assessed quality using QUADAS-2. Pooled sensitivity and specificity were estimated using bivariate random-effects models with SROC curves. Publication bias was evaluated using Deeks' funnel plot and Egger's regression.

RESULTS

Twenty studies met inclusion criteria: 12 evaluating Xpert Carba-R (4,735 samples) and 8 evaluating NG-Test CARBA-5 (3,344 samples); 88% were rated at low risk of bias. Xpert Carba-R demonstrated pooled sensitivity of 99.9% (95% CI: 99.8-100.0%), specificity of 98.4% (95% CI: 97.9-98.9%), AUC of 0.998, and low heterogeneity (I²=15%). NG-Test CARBA-5 showed sensitivity of 98.9% (95% CI: 98.4-99.4%), specificity of 96.3% (95% CI: 95.4-97.2%), AUC of 0.987, and moderate heterogeneity (I²=24%). Xpert Carba-R demonstrated statistically higher diagnostic accuracy (p<0.001), though absolute differences were small (1-2 percentage points). No publication bias was detected (Egger's p=0.18 and p=0.24, respectively).

CONCLUSIONS

Both platforms demonstrate excellent carbapenemase detection accuracy. Xpert Carba-R offers marginally superior performance but requires 50-60 minutes and specialized equipment; NG-Test CARBA-5 delivers results in 15 minutes with minimal infrastructure. Platform selection should integrate local epidemiology, carbapenemase subtypes, and cost. Emerging KPC-2-derived variants with altered epitopes may reduce immunochromatographic accuracy, warranting molecular confirmation in high-risk settings.