key: cord-034481-zi9q96lj
authors: Liu, Yongjian; Li, Tianyi; Deng, Yongqiang; Liu, Siyang; Zhang, Dong; Li, Hanping; Wang, Xiaolin; Jia, Lei; Han, Jingwan; Bei, Zhuchun; Li, Lin; Li, Jingyun
title: Stability of SARS-CoV-2 on environmental surfaces and in human excreta
date: 2020-11-01
journal: J Hosp Infect
DOI: 10.1016/j.jhin.2020.10.021
sha: 
doc_id: 34481
cord_uid: zi9q96lj

nan

At the end of 2019, a novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged and rapidly spread throughout the world.

Although close exposure to respiratory droplets from an infected patient is the main transmission route of SARS-CoV-2, touching contaminated surfaces and objects might also contribute to transmission of this virus. In addition, the evidence for gastrointestinal infection of SARS-CoV-2 and the presence of SARS-CoV-2 RNA in faecal specimens raised a question of a fecal-oral transmission route [1, 2] . Here, we provide a report of our study of the stability of SARS-CoV-2 on various environmental surfaces and in human excreta (feces and urine). These data has great importance for our understanding the transmission of this virus.

Nine different objects representing a variety of household and hospital situations were collected and cut into small pieces with the area about 1×1cm. SARS-CoV-2

BetaCoV/Beijing/AMMS01/2020 was the strain used. Fifty microliters of virus stock with the infectious titer of 10 6 50% tissue culture infectious dose (TCID 50 ) per milliliter was deposited on each surface and left at room temperature. At predefined time points, the viruses were recovered by adding 500μl of viral transport medium.

The infectivity of residual virus was titrated in quadruplicate on 96-well plates containing 100μl of Vero cells (2×10 5 cells/ml). The plates were incubated in 5% CO 2 at 37°C. On the fifth day, the cytopathic effect (CPE) was observed under a microscope, and the TCID 50 for each sample at a different time was calculated with Reed-Muench method. All experiments were repeated three times. SARS-CoV-2 was stable on plastic, stainless steel, glass, ceramics, wood, latex gloves, and surgical mask, and remained viable for seven days on these surfaces. As is shown in Figure 1A , the virus titer declined slowly on these seven surfaces. However, no infectious virus could be recovered from cotton clothes after 4 days and from paper after 5 days.

The specimens of feces and urine were collected from three healthy donors, including two adults and one seven-year-old child. A 10% suspension of each faecal specimen J o u r n a l P r e -p r o o f was prepared in PBS (pH, 7.4) as described previously [3] . A total of 2.7ml of each filtered faecal suspension and urine sample was inoculated with 0.3ml of virus stock and left at room temperature for 7 days. At desired time points, 50μl of each sample was taken and virus titer was determined with the same method described above. Figure 1B shows the duration of SARS-CoV-2 survival in three feces. In the first adult faecal specimen, no viable SARS-CoV-2 was measured after 6 hours, and in the second adult faecal specimen, no virus remained viable after 2 hours. However, the virus survived for 2 days in the child feces. SARS-CoV-2 was more stable in urine than in feces, and infectious virus was detected up to 3 days in two adult urine and 4 days in one child urine.

Prior to our study, two research teams had just reported the stability of SARS-CoV-2 on different material surfaces [4, 5] . In comparison with the above two studies, our data displayed a prolonged survival time of this virus on environmental surfaces. In general, the stability of virus in environments was derived from simulated experiments, which were influenced by many factors. The titer of virus stock and the volume of virus inoculation were related with the final results. Compared with van Doremalen's experiments, we used the same volume of inoculation, but the titer of virus stock was one log unit higher. In Chin's study, a five microliters of virus stock with the infectious titer of 10 6.8 TCID 50 /ml was deposited on the surface. Therefore, 

Evidence for Gastrointestinal Infection of SARS-CoV-2

Prolonged presence of SARS-CoV-2 viral RNA in faecal samples

Survival of severe acute respiratory syndrome coronavirus

Stability of SARS-CoV-2 in different environmental conditions

Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1

Detection of Novel Coronavirus by RT-PCR in Stool Specimen from Asymptomatic Child

Patient-derived mutations impact pathogenicity of SARS-CoV-2