Diagnostic accuracy of non-culture methods for the diagnosis of melioidosis: a systematic review and meta-analysis.

BACKGROUND

The accuracy of laboratory diagnostic tests for the rapid diagnosis of melioidosis and their potential to replace culture tests as the gold standard remain controversial. This study aims to comprehensively evaluate the accuracy of all rapid diagnostic tests.

RESEARCH DESIGN AND METHODS

A systematic search of PubMed, Embase, SCIE, the Cochrane Library, and Scopus databases was conducted up to July 12, 2024, to include diagnostic tests for melioidosis with culture as the gold standard. The diagnostic accuracy of all testing methods was evaluated using a bivariate mixed-effects model and an ANOVA model.

RESULTS

A total of 36 studies, comprising 21,289 tests, were included in this systematic review and meta-analysis. Using the bivariate mixed-effects model, the pooled sensitivity of indirect ELISA was 0.86 [95% CI (0.80-0.90)] and the pooled specificity was 0.85 [95% CI (0.80-0.89)]. For IHA with a positive threshold of 1:160, the pooled sensitivity was 0.60 [95% CI (0.46-0.72)] and the pooled specificity was 0.70 [95% CI (0.58-0.79)]. The pooled sensitivity of LFI targeting CPS was 0.52 [95% CI (0.33-0.70)] and the pooled specificity was 0.96 [95% CI (0.93-0.98)]. For IFA targeting polyclonal antibody, the pooled sensitivity was 0.60 [95% CI (0.44-0.75)] and the pooled specificity was 0.99 [95% CI (0.97-1.00)]. The pooled sensitivity of RT-PCR targeting T3SS was 0.72 [95% CI (0.41-0.91)] and the pooled specificity was 1.00 [95% CI (0.97-0.99)]. Other testing methods could not be meta-analyzed due to insufficient study numbers. The ANOVA model for network meta-analysis of the five most common testing methods showed that IFA targeting polyclonal antibody had the best advantage with a Superiority index of 6.86. In contrast, IHA with a positive threshold of 1:160 had the poorest advantage with a Superiority index of 0.19.

CONCLUSION

While rapid diagnostic methods for B. pseudomallei infection exist, bacterial culture remains the gold standard. In resource-limited settings, we recommend antigen-targeted sandwich ELISA for acute/early-stage melioidosis and IgG-based indirect ELISA for late acute or chronic cases. In high-resource settings, RT-PCR targeting the T3SS is recommended as an adjunct diagnostic modality. Strengthening training for clinicians and laboratory personnel is essential to ensure accurate application and interpretation.

TRIAL REGISTRATION

CRD42024569385.