Detection of silent SARS-CoV-2 infection (S1 File)

Background: To control COVID-19 pandemic is of critical importance to the global public health. To capture the prevalence in an accurate and timely manner and to understand the mode of nosocomial infection are essential for its preventive measure. Methods: We recruited 685 healthcare workers (HCW’s) at Tokyo Shinagawa Hospital prior to the vaccination with COVID-19 vaccine. Sera of the subjects were tested by assays for the titer of IgG against S protein’s receptor binding domain (IgG (RBD)) or IgG against nucleocapsid protein (IgG (N)) of SARS-CoV-2. Together with PCR data, the positive rates by these methods were evaluated. Results: Overall positive rates among HCW’s by PCR, IgG (RBD), IgG (N) with a cut-off of 1.4 S/C (IgG (N)1.4), and IgG (N) with a cut-off of 0.2 S/C (IgG (N)0.2) were 3.5%, 9.5%, 6.1%, and 27.7%, respectively. Positive rates of HCW’s working in COVID-19 ward were significantly higher than those of HCW’s working in non-COVID-19 ward by all the four methods. Concorda...背景：控制新冠疫情对全球公共卫生事业至关重要。准确及时地掌握疫情流行态势，明晰院内感染的传播模式，是制定新冠防控措施的核心前提。 方法：本研究在新冠疫苗接种前，纳入了东京品川医院的685名医护人员（healthcare workers, HCW）。采用血清学检测方法，测定受试者血清中针对新型冠状病毒（Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2）S蛋白受体结合域（receptor binding domain, RBD）的IgG抗体滴度[IgG(RBD)]，以及针对核衣壳蛋白（nucleocapsid protein, N）的IgG抗体滴度[IgG(N)]。结合聚合酶链式反应（Polymerase Chain Reaction, PCR）检测数据，对上述两种血清学方法及PCR的阳性率进行了评估。 结果：整体而言，医护人员中采用PCR、IgG(RBD)、临界值为1.4 S/C的IgG(N)检测（IgG(N)1.4）以及临界值为0.2 S/C的IgG(N)检测（IgG(N)0.2）所得的阳性率依次为3.5%、9.5%、6.1%及27.7%。经四种方法检测，新冠病房医护人员的阳性率均显著高于非新冠病房医护人员。一致性……