Section of Microbiology, Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy.
Eur Rev Med Pharmacol Sci. 2020 Sep;24(17):9202-9207. doi: 10.26355/eurrev_202009_22872.
SARS-CoV-2 can reportedly exist on inanimate surfaces for a long duration, but there is limited data available from Italian COVID-19 hospital wards, especially for non-intensive care units hosting patients that do not require mechanical ventilation. Identification of the extent of environmental contamination can help in understanding possible virus transmission routes, limit hospital infections and protect healthcare workers. Thus, we investigated virus contamination on surfaces of the acute COVID-19 ward of an Italian hospital.
Ward surfaces, including four points inside and six points outside the patients' rooms were sampled by swabs, seven hours after routine sanitation. To minimize the risk of underestimation of virus detection, two different sensitive molecular methods were used comparatively, and specific internal controls were added to enhance the efficiency of all the analysis steps.
SARS-CoV-2 contamination was detected in only three out of all the collected samples, i.e., on two floors and one-bathroom sink, likely reflecting aerosol and saliva contamination, respectively. The overall level of contamination was low, and the floors exhibited a very low level of SARS-CoV-2 presence, evidenced by only one of the two methods used.
The existence of SARS-CoV-2 on hospital surfaces may be limited, although it was reported to persist for a longer duration on surfaces under controlled laboratory conditions. Thus, effective transmission of SARS-CoV-2 by surfaces/fomites within the hospital ward may be a rare event. However, the results highlight the importance of assessing method sensitivity and including controls when investigating low-level virus contamination so as to avoid the risk of underestimation of virus presence.
据报道，SARS-CoV-2 可在无生命表面上长时间存在，但意大利 COVID-19 医院病房的数据有限，特别是对于不接收需要机械通气的患者的非重症监护病房。确定环境污染的程度有助于了解可能的病毒传播途径，限制医院感染并保护医护人员。因此，我们调查了一家意大利医院急性 COVID-19 病房表面的病毒污染情况。
在常规清洁后 7 小时，用拭子对病房内四个点和病房外六个点的病房表面进行采样。为了最大程度地减少低估病毒检测的风险，我们比较使用了两种不同的敏感分子方法，并添加了特定的内部对照，以提高所有分析步骤的效率。
仅在三个采集样本中检测到 SARS-CoV-2 污染，即两个楼层和一个浴室水槽，可能分别反映了气溶胶和唾液污染。污染程度总体较低，且仅使用了两种方法中的一种，表明地板上 SARS-CoV-2 的存在水平极低。
尽管 SARS-CoV-2 在受控实验室条件下可在表面上长时间存在，但它在医院表面上的存在可能是有限的。因此，SARS-CoV-2 通过医院病房内的表面/污染物有效传播可能是罕见事件。但是，这些结果强调了在调查低水平病毒污染时评估方法灵敏度和包含对照的重要性，以避免低估病毒存在的风险。
