Under the Microscope with David Weber: The role of the healthcare surface environment in SARS-CoV-2 transmission and potential control measures

Author: David Weber, MD, MPH, FSHEA, FIDSA, FMSM (London)

This Week’s Review:

The role of the healthcare surface environment in SARS-CoV-2 transmission and potential control measures, written by Kanamori H, Weber DJ, and Rutala WA¹, provides a comprehensive review of the literature that assessed the role of the healthcare surface environment in SARS-CoV-2 transmission. More than 20 studies reviewed assessed surface contamination in hospitals with SARS-CoV-2. The authors noted that human coronaviruses, including SARS-CoV-2, could survive for hours to days on surfaces depending on experimental conditions (i.e., viral titer, surface substrate, temperature and relative humidity).

Overall, the contamination rate of the healthcare environment with SARS-CoV-2 as measured by RT-PCR varied from 0% to 75% (median, 12.1%), depending on the status of cleaning/disinfection in environmental sampling rather than on the symptomatic status of COVID-19 patients. Environmental studies sampled before cleaning/disinfection reported infrequent to frequent contamination while studies samples after cleaning/disinfection revealed zero to infrequent contamination. Only four studies assessed the presence of viable virus by culture, and viable SARS-CoV-2 was not confirmed from environmental samples. However, Santarpia et al. {Sci Rep 2020;10(1):12732} did observe the presence of intact SARS-CoV-2 virions by electron microscopy of a windowsill sample after 3 days of culture.

The authors provided a detailed list of recommendations for cleaning and disinfection of environmental surfaces and medical devices in rooms occupied by known or suspected COVID-19 patients. Key recommendations were as follows:

• Follow CDC recommendations for letting the room remain empty regardless of personal protective equipment after patient discharge for the specified time period;
• Use an EPA-registered disinfectant on EPA List N that has qualified under emerging viral pathogens program for use against SARS-CoV-2;
• All noncritical touchable surfaces and medical devices should be cleaned/disinfected at least once a day and when visibly soiled;
• Assess cleaning thoroughness with a validation method (e.g., fluorescent dye markers); and,
• Consider no-touch methods (e.g., ultraviolet light devices) when available as an adjunct to chemical disinfection for terminal disinfection.

Under the Microscope with Dr. David Weber explores what’s new in industry literature and provides a synopsis, along with key takeaways.