Wang Dan, Zhu Dan, Xia Min, Wang Xiaoying, Zou Ni
Department of Infection Prevention and Control, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Heliyon. 2024 May 29;10(11):e32182. doi: 10.1016/j.heliyon.2024.e32182. eCollection 2024 Jun 15.
The COVID-19 pandemic has exposed healthcare workers (HCWs) to serious risk of infection. The aims of our study were to investigate the epidemiological characteristics and risk factors of SARS-CoV-2 infection among HCWs, and evaluate the vaccine effectiveness (VE) during the Omicron pandemic in Shanghai, China.
Active surveillance of COVID-19 was performed among HCWs who worked in Shanghai General Hospital from December 2022 to January 2023. A case-control study was conducted by questionnaire survey to analyse the infection-related risk factors. A retrospective cohort study was explored to evaluate VE against primary infection.
During the Omicron outbreak, 2,008 of 2,460 (81.6%) HCWs were infected with SARS-CoV-2. The infection rate was higher in women, younger age groups, nurses and medical technicians. Among the 1,742 participants in the questionnaire, 1,463 (84.0%) were tested positive, and 95.1% of them developed symptoms. Most of the infections (53.0%) were acquired outside the hospital. The risk factors associated with higher odds of infection were working in the emergency department (aOR 3.77, 95% CI 1.69-8.38) and medical examination area (aOR 2.47, 95% CI 1.10-5.51). The protective factors associated with lower odds of infection were previous infection with SARS-CoV-2 (aOR 0.01, 95% CI 0-0.07) and receiving four doses of vaccines (aOR 0.40, 95% CI 0.17-0.97). For frontline HCWs, those who had oral-nasal exposure to coworkers were more likely to be infected (aOR 1.74, 95% CI 1.21-2.51). In VE analysis, the risk of primary infection was lower in HCWs who received the emergency heterologous booster (the fourth dose) during the epidemic (aHR 0.25, 95% CI 0.15-0.40), resulting in an adjusted-VE of 75.1%.
In response to future pandemic, it is important for public health policies to aim at protecting HCWs through risk-differentiated infection control measures, strengthening personal protection and recommending vaccination to vulnerable individuals before the arrival of Omicron wave.
新型冠状病毒肺炎（COVID-19）大流行使医护人员面临严重感染风险。我们研究的目的是调查医护人员中严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染的流行病学特征和危险因素，并评估中国上海奥密克戎大流行期间的疫苗有效性（VE）。
对2022年12月至2023年1月在上海交通大学医学院附属瑞金医院工作的医护人员进行COVID-19主动监测。通过问卷调查进行病例对照研究，分析感染相关危险因素。采用回顾性队列研究评估针对初次感染的疫苗有效性。
在奥密克戎疫情期间，2460名医护人员中有2008名（81.6%）感染了SARS-CoV-2。女性、较年轻年龄组、护士和医技人员的感染率较高。在1742名参与问卷调查的人员中，1463名（84.0%）检测呈阳性，其中95.1%出现症状。大多数感染（53.0%）发生在医院外。与感染几率较高相关的危险因素是在急诊科工作（调整后比值比[aOR]3.77，95%置信区间[CI]1.69-8.38）和体检区工作（aOR 2.47，95%CI 1.10-5.51）。与感染几率较低相关的保护因素是既往感染过SARS-CoV-2（aOR 0.01，95%CI 0-0.07）和接种四剂疫苗（aOR 0.40，95%CI 0.17-0.97）。对于一线医护人员，那些口鼻接触过同事的人更容易感染（aOR 1.74，95%CI 1.21-2.51）。在疫苗有效性分析中，疫情期间接受紧急异源加强针（第四剂）的医护人员初次感染风险较低（调整后风险比[aHR]0.25，95%CI 0.15-0.40），调整后的疫苗有效性为75.1%。
为应对未来的大流行，公共卫生政策应旨在通过差异化的感染控制措施保护医护人员，加强个人防护，并在奥密克戎浪潮到来之前向易感人群推荐接种疫苗。
