Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China.
Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China.
Int J Infect Dis. 2020 Oct;99:219-225. doi: 10.1016/j.ijid.2020.07.082. Epub 2020 Aug 3.
To investigate the proportion and characteristics of asymptomatic infection among healthcare workers (HCWs).
This study retrospectively investigated 1407 HCWs who were screened for COVID-19 by chest computed tomography (CT) scans and nasopharyngeal swabs for SARS-CoV-2 nucleic acid. Demographics, CT features, nasopharyngeal swabs, baseline symptoms, and laboratory data were collected.
Of 1407 HCWs, 235 had symptoms and 1172 were asymptomatic close contacts, of which, 107 were symptomatic cases and 84 were close contacts who had abnormal CT findings. Of 152 symptomatic individuals and 908 close contacts tested for SARS-CoV-2 nucleic acid, 122 symptomatic cases and 38 close contacts had positive reverse-transcriptase real-time polymerase chain (RT-PCR) test results. The rate of confirmed asymptomatic infections was 4.2% (38/908). Both symptomatic and asymptomatic infected cases had high titrations of specific IgG or had ≥four-fold increase in IgG during convalescence compared with the acute phase. Combining the RT-PCR tests and serological findings, the rate of asymptomatic infections was 9.7% (88/908). In terms of the duration of viral shedding, there was no significant difference between symptomatic mild/moderate participants and asymptomatic infections.
The findings demonstrated that a high rate of asymptomatic SARS-CoV-2 carriers existed among healthcare worker close contacts during the outbreak of COVID-19.
调查医护人员（HCWs）无症状感染的比例和特征。
本研究回顾性调查了 1407 名通过胸部计算机断层扫描（CT）扫描和鼻咽拭子检测 SARS-CoV-2 核酸筛查的 HCWs。收集了人口统计学、CT 特征、鼻咽拭子、基线症状和实验室数据。
在 1407 名 HCWs 中，235 名有症状，1172 名无症状密切接触者，其中 107 名有症状，84 名有异常 CT 发现的密切接触者。在 152 名有症状个体和 908 名密切接触者中检测 SARS-CoV-2 核酸，122 名有症状病例和 38 名有异常 CT 发现的密切接触者的逆转录实时聚合酶链反应（RT-PCR）检测结果为阳性。确诊无症状感染的发生率为 4.2%（38/908）。与急性期相比，有症状和无症状感染病例的特异性 IgG 滴度均较高，或恢复期 IgG 滴度增加≥4 倍。将 RT-PCR 检测和血清学结果相结合，无症状感染的发生率为 9.7%（88/908）。在病毒脱落持续时间方面，症状轻微/中度患者与无症状感染者之间无显著差异。
在 COVID-19 爆发期间，医护人员密切接触者中存在大量无症状 SARS-CoV-2 携带者。
