Our study demonstrates extensive environmental contamination of SARS-CoV-2 RNA in a relatively short time (<24 hours) in occupied rooms of 2 persons who were presymptomatic. We also detected SARS-CoV-2 RNA in the surface swab samples of the pillow cover, duvet cover, and sheet.
Evidence for SARS-CoV-2 transmission by indirect contact was identified in a cluster of infections at a shopping mall in China. However, no clear evidence of infection caused by contact with the contaminated environment was found. SARS-CoV-2 RNA has been detected on environmental surfaces in isolation rooms where the symptomatic or paucisymptomatic patients stayed for several days.[3–5] In our study, we demonstrate high viral load shedding in presymptomatic patients, which is consistent with previous studies,[8,9] providing further evidence for the presymptomatic transmission of the virus.[5,11–15] In addition, presymptomatic patients with high viral load shedding can easily contaminate the environment in a short period.
Our results also indicate a higher viral load detected after prolonged contact with sheets and pillow covers than with intermittent contact with the door handle and light switch. The detection of SARS-CoV-2 RNA in the surface samples of the sheet, duvet cover, and pillow cover highlights the importance of proper handling procedures when changing or laundering used linens of SARS-CoV-2 patients. Thus, to minimize the possibility of dispersing virus through the air, we recommend that used linens not be shaken upon removal and that laundered items be thoroughly cleaned and dried to prevent additional spread.
The absence of viral isolation in our investigation was an obstacle to demonstrating the infectivity of the virus, but SARS-CoV-2 has been reported to remain viable on surfaces of plastic and stainless steel for up to 4–7 days[6,7] and 1 day for treated cloth. In summary, our study demonstrates that presymptomatic patients have high viral load shedding and can easily contaminate environments. Our data also reaffirm the potential role of surface contamination in the transmission of SARS-CoV-2 and the importance of strict surface hygiene practices, including regarding linens of SARS-CoV-2 patients.
This work was supported by the National Major Project for Control and Prevention of Infectious Disease of China (2017ZX10303401-006), the National Natural Science Foundation of China (81773494 and 81621005), and the Special National Project on investigation of basic resources of China (2019FY101502).
Emerging Infectious Diseases. 2020;26(9):2162-2164. © 2020 Centers for Disease Control and Prevention (CDC)