S1 Data -

Introduction
Health care workers (HCWs) are crucial to the fight against COVID-19 and are at risk of being infected. We sought to determine the risk factors and associations of COVID-19 among HCWs in Ghana during the period of the pandemic.
Materials and methods
A case-control study was conducted using the WHO COVID-19 HCWs exposure risk assessment tool. A HCW was categorized as “high risk” for COVID-19 if s/he did not respond “always, as recommended” to adherence to Infection Prevention and Control (IPC) measures during a healthcare interaction. A HCW was categorized as “low risk” if s/he responded “always, as recommended” to adherence to IPC measures. We used univariate and multiple logistic regression models to determine associated risk factors. Statistical significance was set at 5%.
Results
A total of 2402 HCWs were recruited and the mean age was 33.2±7.1 years. Almost 87% (1525/1745) of HCWs had high risk for COVID-19 infection. Risk factors identified were profession (doctor- aOR: 2.13, 95%CI: 1.54–2.94; radiographer—aOR: 1.16, 95% CI: 0.44–3.09)), presence of comorbidity (aOR: 1.89, 95%CI: 1.29–2.78), community exposure to virus (aOR: 1.26, 95% CI: 1.03–1.55), not performing hand hygiene before and after aseptic procedures performed (aOR: 1.6, 95% CI: 1.05–2.45); not frequently decontaminating high-touch surfaces always as recommended (aOR: 2.31, 95%CI: 1.65–3.22; p = 0.001) and contact with a confirmed COVID-19 patient (aOR: 1.39, 95% CI: 1.15–1.67). Among those who came into any form of contact with confirmed COVID-19 patient, providing direct care (aOR: 2.0, 95%CI: 1.36–2.94), face-to-face contact (aOR: 2.23, 95%CI: 1.41–3.51), contact with environment/materials used by COVID-19 patient (aOR: 2.25, 95%CI: 1.45–3.49) and presence during conduct of aerosol generating procedures (aOR: 2.73, 95%CI: 1.74–4.28) were associated with COVID-19 infection.
Conclusion
Non-adherence to IPC guidelines puts HCWs at increased risk of COVID-19 infection thus ensuring IPC adherence is key to reducing this risk.

引言
医护人员（Health care workers, HCWs）是抗击新冠疫情的核心力量，同时面临感染新冠病毒的风险。本研究旨在探究加纳地区新冠大流行期间，医护人员感染新冠病毒的危险因素及其相关关联。

材料与方法
本研究采用世界卫生组织（WHO）新冠医护人员暴露风险评估工具开展病例对照研究。若医护人员在医疗操作过程中，未按照要求始终如一地遵守感染预防与控制（Infection Prevention and Control, IPC）措施，则将其归类为新冠病毒感染“高风险”人群；若其始终如一地遵守IPC措施，则归类为“低风险”人群。本研究采用单因素及多因素logistic回归模型分析相关危险因素，设定统计学显著性阈值为5%。

结果
本研究共招募2402名医护人员，平均年龄为33.2±7.1岁。近87%（1525/1745）的医护人员存在新冠病毒感染高风险。本研究识别出的危险因素包括：职业因素（医生：调整后比值比（adjusted Odds Ratio, aOR）为2.13，95%置信区间（95% Confidence Interval, 95%CI）为1.54~2.94；放射技师：aOR为1.16，95%CI为0.44~3.09）、合并基础疾病（aOR=1.89，95%CI=1.29~2.78）、社区病毒暴露风险（aOR=1.26，95%CI=1.03~1.55）、无菌操作前后未执行手卫生（aOR=1.6，95%CI=1.05~2.45）、未按要求始终如一地对高频接触表面进行消毒（aOR=2.31，95%CI=1.65~3.22；P=0.001）以及与确诊新冠患者接触（aOR=1.39，95%CI=1.15~1.67）。在与确诊新冠患者存在任何形式接触的医护人员中，提供直接护理（aOR=2.0，95%CI=1.36~2.94）、面对面接触（aOR=2.23，95%CI=1.41~3.51）、接触新冠患者使用过的环境或物品（aOR=2.25，95%CI=1.45~3.49）以及参与气溶胶产生操作（aOR=2.73，95%CI=1.74~4.28）均与新冠病毒感染显著相关。

结论
不遵守IPC指南会增加医护人员感染新冠病毒的风险，因此确保严格遵守IPC措施是降低此类风险的关键。