End-to-End Protocol for the Detection of SARS-CoV-2 from Built Environments

Area of Science:

• Environmental Science
• Virology
• Public Health

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19, primarily spreading through respiratory droplets.
• Virions can remain infectious on surfaces for up to 72 hours, posing a risk of transmission via contact.
• Understanding surface contamination and effective detection methods is crucial for public health interventions.

Purpose of the Study:

• To determine the efficiency of protocols for recovering SARS-CoV-2 from surfaces in built environments.
• To identify an optimal end-to-end (E2E) workflow for SARS-CoV-2 surface monitoring.
• To assess the persistence of viral RNA on surfaces, even after disinfection.

Main Methods:

• An end-to-end (E2E) study was conducted using specific swab collection tools, preservatives, automated RNA extraction, and RT-qPCR detection.
• The study evaluated the minimum viral load required for detection on various surfaces.
• Inhibition effects of surface debris on RNA recovery were investigated.

Main Results:

• An effective E2E protocol involves Isohelix swabs, DNA/RNA Shield, automated extraction, and RT-qPCR, requiring a minimum of 1,000 viral particles/25 cm².
• Non-infectious SARS-CoV-2 viral fragments persisted on surfaces for up to 8 days, even post-bleach treatment.
• Surface debris, particularly from Amerstat, significantly inhibited RNA recovery (>90%).

Conclusions:

• The developed E2E protocol provides a reliable method for SARS-CoV-2 surface monitoring in built environments.
• While viral RNA can persist, the study found no detectable SARS-CoV-2 on 368 tested environmental surface samples.
• This research offers valuable insights into surface disinfection efficacy and viral RNA retention capabilities.