SARS-CoV-2 RNA Is Readily Detectable at Least 8 Months after Shedding in an Isolation Facility

Area of Science:

• Environmental science
• Virology
• Public Health

Background:

• Environmental monitoring for SARS-CoV-2 (COVID-19) has expanded for public health surveillance.
• Wastewater monitoring offers early warning signals, but indoor surface monitoring utility is less established.
• A key challenge in surface monitoring is distinguishing recent virus from "relic RNA" (noninfectious genetic material).

Purpose of the Study:

• To determine the persistence of SARS-CoV-2 RNA on surfaces in an isolation unit after a COVID-19-positive individual departed.
• To assess the potential for relic RNA to confound environmental monitoring efforts.

Main Methods:

• SARS-CoV-2 RNA detection via sequencing on surfaces within a university dorm room isolation unit.
• Sampling conducted over time, including up to 8 months after the room was vacated.
• Sequence analysis to confirm viral genome presence and source similarity.

Main Results:

• SARS-CoV-2 RNA was detected on surfaces for up to 8 months post-occupancy.
• Full viral genomes were identified, with sequence similarity indicating a single source.
• Findings demonstrate significant persistence of viral RNA in the indoor environment.

Conclusions:

• SARS-CoV-2 RNA can persist on surfaces for extended periods, posing a challenge for interpreting environmental monitoring data.
• Approaches to environmental monitoring must account for relic RNA to accurately assess current infectious risks.
• Further research is needed to develop methods for differentiating infectious virus from persistent RNA in environmental samples.