Objective: To determine the environmental contamination degree of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in corona virus disease 2019 (COVID-19) wards, to offer gui-dance for the infection control and to improve safety practices for medical staff, by sampling and detecting SARS-CoV-2 nucleic acid from the air of hospital wards, the high-frequency contact surfaces in the contaminated area and the surfaces of medical staff's protective equipment in a COVID-19 designated hospital in Wuhan, China.
Methods: From March 11 to March 19, 2020, we collected air samples from the clean area, the buffer room and the contaminated area respectively in the COVID-19 wards using a portable bioaerosol concentrator WA-15. And sterile premoistened swabs were used to sample the high-frequency contacted surfaces in the contaminated area and the surfaces of medical staff's protective equipment including outermost gloves, tracheotomy operator's positive pressure respiratory protective hood and isolation clothing. The SARS-CoV-2 nucleic acid of the samples were detected by real-time fluorescence quantitative PCR. During the isolation medical observation period, those medical staff who worked in the COVID-19 wards were detected for SARS-CoV-2 nucleic acid with oropharyngeal swabs, IgM and IgG antibody in the sera, and chest CT scans to confirm the infection status of COVID-19.
Results: No SARS-CoV-2 nucleic acid was detected in the tested samples, including the 90 air samples from the COVID-19 wards including clean area, buffer room and contaminated area, the 38 high-frequency contact surfaces samples of the contaminated area and 16 surface samples of medical staff's protective equipment including outermost gloves and isolation clothing. Moreover, detection of SARS-CoV-2 nucleic acid by oropharyngeal swabs and IgM, IgG antibodies in the sera of all the health-care workers who participated in the treatment for COVID-19 were all negative. Besides, no chest CT scan images of medical staff exhibited COVID-19 lung presentations.
Conclusion: Good ventilation conditions, strict disinfection of environmental facilities in hospital wards, guidance for correct habits in patients, and strict hand hygiene during medical staff are important to reduce the formation of viral aerosols, cut down the aerosol load, and avoid cross-infection in isolation wards. In the face of infectious diseases that were not fully mastered but ma-naged as class A, it is safe for medical personnel to be equipped at a high level.
目的: 对武汉某定点医院新型冠状病毒肺炎(corona virus disease 2019，COVID-19)病区内的空气、污染区高频接触物体表面及医务人员防护服表面采样，并检测新型冠状病毒(severe acute respiratory syndrome coronavirus 2，SARS-CoV-2)核酸，以明确病区内SARS-CoV-2污染程度，指导感染控制，保证医务人员安全。
方法: 于2020年3月11—19日，使用便携式生物气溶胶采样器WA-15采集病区内清洁区、缓冲区及污染区的空气样本，应用预湿无菌棉签涂抹法采集污染区高频接触物体表面样本和医务人员防护服表面样本(最外层手套表面以及气管切开操作者正压呼吸防护头套和隔离衣表面)，采用实时荧光定量PCR方法检测样本中的SARS-CoV-2核酸。隔离医学观察期间对病区内工作过的医务人员行咽拭子SARS-CoV-2核酸检测，血清SARS-CoV-2 IgM、IgG抗体检测及胸部CT扫描明确医务人员COVID-19感染情况。
结果: 病区内90个清洁区、缓冲区及污染区空气样本，38个污染区高频接触物体表面样本和16个医务人员防护服表面样本，均未检出SARS-CoV-2核酸。137位在病区参与COVID-19救治工作的医务人员咽拭子SARS-CoV-2核酸检查结果均阴性，血清SARS-CoV-2 IgM、IgG抗体均阴性，胸部CT检查均无COVID-19肺部影像学表现。
结论: 良好的通风条件、严格环境设施消毒、正确的患者生活习惯指导以及医务人员严格手卫生，是减少隔离病房内病毒气溶胶形成、降低气溶胶含量、避免交叉感染的重要保证。面对未完全掌握的按甲类管理的传染病，医务人员按高级别防护是安全的。
Keywords: Coronavirus infections; Disease transmission, infectious; Health personnel; Patient isolation; Pneumonia, viral.