UNASSIGNED: 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.
UNASSIGNED: 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%.
UNASSIGNED: 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.
■2022年12月至2023年1月在上海市总医院工作的医护人员中对COVID-19进行了主动监测。采用问卷调查法进行病例对照研究,分析感染相关危险因素。进行了一项回顾性队列研究,以评估VE对原发感染的影响。
■在Omicron爆发期间,2,460例(81.6%)HCWs中有2,008例感染了SARS-CoV-2。女性感染率较高,年轻的年龄组,护士和医疗技术人员。在问卷的1742名参与者中,1,463(84.0%)检测呈阳性,其中95.1%出现症状。大多数感染(53.0%)是在医院外获得的。与较高感染几率相关的危险因素在急诊科(aOR3.77,95%CI1.69-8.38)和医学检查领域(aOR2.47,95%CI1.10-5.51)。与较低感染几率相关的保护因素是既往感染SARS-CoV-2(aOR0.01,95%CI0-0.07)和接受四剂疫苗(aOR0.40,95%CI0.17-0.97)。对于前线HCW,经口鼻接触同事的患者更有可能受到感染(aOR1.74,95%CI1.21~2.51).在VE分析中,在流行期间接受紧急异源加强剂(第四剂)的HCWs的原发感染风险较低(aHR0.25,95%CI0.15-0.40),导致调整后的VE为75.1%。
■为了应对未来的大流行,对于公共卫生政策而言,重要的是通过风险区分感染控制措施来保护HWs,加强个人保护,并在Omicron波到来之前向易受伤害的个人推荐疫苗接种。