Simulated sunlight decreases the viability of SARS-CoV-2

Abstract

The novel coronavirus, SARS-CoV-2, has spread into a pandemic since its emergence in Wuhan, China in December of 2019. This has been facilitated by its high transmissibility within the human population and its ability to remain viable on inanimate surfaces for an extended period. To address the latter, we examined the ability of sunlight to degrade SARS-CoV-2 on stainless steel. All assays were performed using a solar simulator at the equivalent of one air mass (i.e. equatorial sun at its Zenith). Heat-controlled experiments were conducted at approximately 34% relative humidity (RH); otherwise, RH decreased with sunlight exposure until a constant temperature was maintained. When initially suspended in tissue culture medium, the virus was rendered non-viable after two hours of sunlight exposure. However, when suspended in an organic matrix designed to mimic bodily secretions, three hours of continuous sunlight was required for complete degradation. From this work, we demonstrate that sunlight represents an effective decontamination method but the speed of decontamination is variable based on the underlying matrix. This information has an important impact on the development of infection prevention and control protocols to reduce the spread of this deadly pathogen.

A Systematic Review of Surface Contamination, Stability, and Disinfection Data on SARS-CoV-2 (Through July 10, 2020)

“…Overall, 27 studies were included with data on surface disinfection, − including 12 studies − reference chained from an extensive systematic review completed by Kampf et al on surface disinfection summarizing pre-SARS-CoV-2 research on other coronaviruses and surrogates, two studies completed post-Kampf using surrogates (AIV on hands; Phi6 on plastic), and 13 studies ,,− , completed post-Kampf using the SARS-CoV-2 virus. The complete surface disinfection data set can be found in Microsoft Excel format in Supporting Information (Table S4).…”

“…In the 13 post-Kampf articles ,,− , that tested SARS-CoV-2, 11 (85%) were pre-prints. ,,,,,− , A total of 94 individual tests were extracted from this data. Disinfectant contact time varied from 10 seconds to 180 min.…”

“…Of the 10 results tested on surfaces: simulated sunlight was found to have >4 log-reduction of SARS-CoV-2 on stainless steel surfaces with 60 min contact time, deep-UV LED irradiation was found to have >3.3 log-reduction of SARS-CoV-2 on hard surfaces with 280 nm wavelength and 20 second contact time, and UV–C irradiation at 200–280 nm was found to have >4 log-reduction of SARS-CoV-2 on hard surfaces with 2 min contact time (Table ). In summary, the only results with SARS-CoV-2 on actual surfaces are with sunlight/UV/irradiation.…”