Nucleic acid and antigen detection tests for leptospirosis

Area of Science:

• Infectious Diseases
• Diagnostic Accuracy
• Molecular Diagnostics

Background:

• Early diagnosis of leptospirosis is crucial for effective antimicrobial therapy and outbreak recognition.
• Nucleic acid and antigen detection tests offer potential for early leptospirosis diagnosis.
• This systematic review evaluates the diagnostic accuracy of these tests.

Purpose of the Study:

• To determine the diagnostic test accuracy of nucleic acid and antigen detection tests for human symptomatic leptospirosis.
• Assessing sensitivity and specificity of various molecular and antigen-based tests.
• Providing evidence for the utility of these tests in clinical settings.

Main Methods:

• Systematic review and meta-analysis of diagnostic accuracy studies.
• Searched multiple databases (MEDLINE, Embase, Cochrane) up to July 2018.
• Assessed risk of bias using QUADAS-2 and pooled data using bivariate and hierarchical models.

Main Results:

• Included 41 studies with 5981 participants evaluating nine index tests.
• Pooled sensitivity for PCR was 70% (95% CI 37%–90%) and specificity was 95% (95% CI 75%–99%).
• Excluding high-risk bias studies improved PCR sensitivity to 87% and specificity to 97%; real-time PCR showed variable sensitivity (29%–49%) at high specificities (85%–95%).

Conclusions:

• Findings on PCR and real-time PCR accuracy are limited by substantial between-study variability and should be interpreted cautiously.
• Optimal use depends on regional leptospirosis prevalence and influencing factors.
• More research is needed to confirm preliminary evidence of higher sensitivity for PCR/real-time PCR on early-stage samples.