Can Testing Predict SARS-CoV-2 Infectivity? The Potential for Certain Methods To Be Surrogates for...

Area of Science:

• Infectious Diseases
• Molecular Diagnostics
• Virology

Background:

• Molecular methods, such as real-time PCR, are primary COVID-19 diagnostic tools.
• These tests detect SARS-CoV-2 RNA long after clinical recovery, complicating isolation guidelines.
• Current assays cannot distinguish between noninfectious remnant RNA and infectious, replication-competent virus.

Purpose of the Study:

• To review the utility of existing diagnostic assays in predicting active SARS-CoV-2 infection.
• To discuss the potential of new molecular methods for determining viral infectivity.
• To inform strategies for discontinuing isolation precautions and managing personal protective equipment use.

Main Methods:

• Review of current literature on molecular diagnostic assays for SARS-CoV-2.
• Analysis of real-time PCR and antigen test performance in predicting active infection.
• Evaluation of novel molecular assays targeting viral RNA intermediates (e.g., subgenomic RNA).

Main Results:

• Existing molecular and antigen tests have limitations in predicting active viral replication.
• Remnant viral RNA detection does not equate to infectiousness.
• Emerging assays show promise in differentiating between infectious and noninfectious viral particles.

Conclusions:

• There is a critical need for diagnostic tests that can accurately predict SARS-CoV-2 infectivity.
• New molecular strategies targeting viral RNA intermediates may offer improved prediction of transmission potential.
• Accurate prediction of infectivity can optimize patient isolation protocols and resource allocation.