COVID diagnostics by molecular methods: A systematic review of nucleic acid based testing systems

Area of Science:

• Molecular Diagnostics
• Virology
• Clinical Microbiology

Background:

• Numerous SARS-CoV-2 diagnostic kits and PCR equipment are available for COVID-19 detection.
• Diagnostic technologies have limitations, leading to false positives/negatives, especially early in development.
• This article guides medical microbiologists in selecting and interpreting PCR-based COVID-19 diagnostic services.

Purpose of the Study:

• To address the critical selection of appropriate kits and PCR equipment for SARS-CoV-2 detection.
• To provide insights into the performance variations and limitations of available molecular diagnostic technologies.
• To aid medical microbiologists in running and aspiring to run COVID-19 diagnostic services.

Main Methods:

• Systematic Review following Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA).
• Screening of 258 citations, with 77 peer-reviewed articles assessed for eligibility.
• Data extraction based on predefined inclusion criteria.

Main Results:

• Diagnostic dilemmas including discordant results, inter-test variability, and inconclusive results were addressed.
• Kit efficiency was satisfactory, but detection rates varied across sample types and technologies.
• No significant cross-reactivity with other respiratory viruses was observed, except for SARS-CoV-1.

Conclusions:

• SARS-CoV-2 molecular assays exhibit considerable performance differences.
• Understanding the interpretation of molecular diagnostic tests is essential for the current pandemic virus.