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Breath-, air- and surface-borne SARS-CoV-2 in hospitals

Zhou, Lian and Yao, Maosheng and Zhang, Xiang and Hu, Bicheng and Li, Xinyue and Chen, Haoxuan and Zhang, Lu and Liu, Yun and Du, Meng and Sun, Bochao and Jiang, Yunyu and Zhou, Kai and Hong, Jie and Yu, Na and Ding, Zhen and Xu, Yan and Hu, Min and Morawska, Lidia and Grinshpun, Sergey A. and Biswas, Pratim and Flagan, Richard C. and Zhu, Baoli and Liu, Wenqing and Zhang, Yuanhang (2020) Breath-, air- and surface-borne SARS-CoV-2 in hospitals. Journal of Aerosol Science . ISSN 0021-8502. (In Press)

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The COVID-19 pandemic has brought an unprecedented crisis to the global health sector. When discharging COVID-19 patients in accordance with throat or nasal swab protocols using RT-PCR, the potential risk of reintroducing the infection source to humans and the environment must be resolved. Here, 14 patients including 10 COVID-19 subjects were recruited; exhaled breath condensate (EBC), air samples and surface swabs were collected and analyzed for SARS-CoV-2 using reverse transcription-polymerase chain reaction (RT-PCR) in four hospitals with applied natural ventilation and disinfection practices in Wuhan. Here we discovered that 22.2% of COVID-19 patients (n = 9), who were ready for hospital discharge based on current guidelines, had SARS-CoV-2 in their exhaled breath (~10⁵ RNA copies/m³). Although fewer surface swabs (3.1%, n = 318) tested positive, medical equipment such as face shield frequently contacted/used by healthcare workers and the work shift floor were contaminated by SARS-CoV-2 (3–8 viruses/cm²). Three of the air samples (n = 44) including those collected using a robot-assisted sampler were detected positive by a digital PCR with a concentration level of 9–219 viruses/m³. RT-PCR diagnosis using throat swab specimens had a failure rate of more than 22% in safely discharging COVID-19 patients who were otherwise still exhaling the SARS-CoV-2 by a rate of estimated ~1400 RNA copies per minute into the air. Direct surface contact might not represent a major transmission route, and lower positive rate of air sample (6.8%) was likely due to natural ventilation (1.6–3.3 m/s) and regular disinfection practices. While there is a critical need for strengthening hospital discharge standards in preventing re-emergence of COVID-19 spread, use of breath sample as a supplement specimen could further guard the hospital discharge to ensure the safety of the public and minimize the pandemic re-emergence risk.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Yao, Maosheng0000-0002-1442-8054
Zhang, Xiang0000-0003-4462-3798
Li, Xinyue0000-0002-0822-4960
Chen, Haoxuan0000-0001-8398-9093
Morawska, Lidia0000-0002-0594-9683
Grinshpun, Sergey A.0000-0003-4339-927X
Biswas, Pratim0000-0003-1104-3738
Flagan, Richard C.0000-0001-5690-770X
Alternate Title:Detection of SARS-CoV-2 in Exhaled Breath from COVID-19 Patients Ready for Hospital Discharge
Additional Information:© 2020 Elsevier Ltd. Received 4 September 2020, Revised 5 October 2020, Accepted 6 October 2020, Available online 15 October 2020. This research was equally supported by the Chinese Academy of Engineering Grant (2020-ZD-15), and a National Natural Science Foundation of China (NSFC) grant (22040101) (PI: M. Yao) dedicated to the COVID-19 pandemic. This work was also partially supported by the NSFC Distinguished Young Scholars Fund Awarded to M. Yao (21725701), and the Scientific Research Fund of Jiangsu Provincial Health Committee (S2017002).
Funding AgencyGrant Number
Chinese Academy of Engineering2020-ZD-15
National Natural Science Foundation of China22040101
National Natural Science Foundation of China21725701
Scientific Research Fund of Jiangsu Provincial Health CommitteeS2017002
Subject Keywords:COVID-19; SARS-CoV-2; Exhaled breath; Airborne transmission; Surface-borne
Record Number:CaltechAUTHORS:20201027-093242333
Persistent URL:
Official Citation:Lian Zhou, Maosheng Yao, Xiang Zhang, Bicheng Hu, Xinyue Li, Haoxuan Chen, Lu Zhang, Yun Liu, Meng Du, Bochao Sun, Yunyu Jiang, Kai Zhou, Jie Hong, Na Yu, Zhen Ding, Yan Xu, Min Hu, Lidia Morawska, Sergey A. Grinshpun, Pratim Biswas, Richard C. Flagan, Baoli Zhu, Wenqing Liu, Yuanhang Zhang, Breath-, air- and surface-borne SARS-CoV-2 in hospitals, Journal of Aerosol Science, 2020, 105693, ISSN 0021-8502,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106296
Deposited By: Tony Diaz
Deposited On:27 Oct 2020 18:31
Last Modified:20 Nov 2020 17:06

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