Toilets dominate environmental detection of SARS-CoV-2 virus in a hospital

Zhen Ding; Hua Qian; Bin Xu; Ying Huang; Te Miao; Hui-Ling Yen; Shenglan Xiao; Lunbiao Cui; Xiaosong Wu; Wei Shao; Yan Song; Li Sha; Lian Zhou; Yan Xu; Baoli Zhu; Yuguo Li

It should be noted that the toilet is a small area that is commonly shared by patients in the relatively large isolation rooms. Thus, the personal spaces of these patients overlap in the toilet area, and thus are likely to generate an additive contamination effect, and may explain why the toilet surfaces were particularly likely to be positive. Nevertheless, the duration of a patient's stay in the toilet is brief as only mild-symptomatic patients stayed on this floor. Additionally, the surface material or finish inside the toilets may allow a better transfer during sampling by swabs. In this context, it is known that there is generally a higher surfacetouch transfer rate from smooth to rough surfaces, and most toilet surfaces are made to be smooth . 13 We failed to detect any viruses on non-toilet object surfaces in the patients' rooms, unlike in a 2020 study by Ong et al, 11 who detected 13/15 (87%) positive samples in one patient's room, and 3/5 (60%) in toilet sites, although anteroom and corridor samples were negative. It is interesting that the patient in their study had no pneumonia or diarrhoea, but that his/her stool samples were positive for SARS-CoV-2. Table 2 . Statistical significance of the positive results for toilet-related surfaces or surfaces in isolation rooms containing at least one patient who had all-positive throat swabs before and/or after the sampling. Other surfaces beyond 36 0 (0%) All rights reserved. No reuse allowed without permission.