Department of Internal Medicine, Cantonal Hospital of Grisons, Chur, Switzerland.
Division of Infectious Diseases, Cantonal Hospital of Grisons, 7000, Chur, Switzerland.
Antimicrob Resist Infect Control. 2022 Jan 10;11(1):6. doi: 10.1186/s13756-021-01047-x.
Health care workers (HCW) are heavily exposed to SARS-CoV-2 from the beginning of the pandemic. We aimed to analyze risk factors for SARS-CoV-2 seroconversion among HCW with a special emphasis on the respective healthcare institutions' recommendation regarding the use of FFP-2 masks.
We recruited HCW from 13 health care institutions (HCI) with different mask policies (type IIR surgical face masks vs. FFP-2 masks) in Southeastern Switzerland (canton of Grisons). Sera of participants were analyzed for the presence of SARS-CoV-2 antibodies 6 months apart, after the first and during the second pandemic wave using an electro-chemiluminescence immunoassay (ECLIA, Roche Diagnostics). We captured risk factors for SARS-CoV-2 infection by using an online questionnaire at both time points. The effects of individual COVID-19 exposure, regional incidence and FFP-2 mask policy on the probability of seroconversion were evaluated with univariable and multivariable logistic regression.
SARS-CoV-2 antibodies were detected in 99 of 2794 (3.5%) HCW at baseline and in 376 of 2315 (16.2%) participants 6 months later. In multivariable analyses the strongest association for seroconversion was exposure to a household member with known COVID-19 (aOR: 19.82, 95% CI 8.11-48.43, p < 0.001 at baseline and aOR: 8.68, 95% CI 6.13-12.29, p < 0.001 at follow-up). Significant occupational risk factors at baseline included exposure to COVID-19 patients (aOR: 2.79, 95% CI 1.28-6.09, p = 0.010) and to SARS-CoV-2 infected co-workers (aOR: 2.50, 95% CI 1.52-4.12, p < 0.001). At follow up 6 months later, non-occupational exposure to SARS-CoV-2 infected individuals (aOR: 2.54, 95% CI 1.66-3.89 p < 0.001) and the local COVID-19 incidence of the corresponding HCI (aOR: 1.98, 95% CI 1.30-3.02, p = 0.001) were associated with seroconversion. The healthcare institutions' mask policy (surgical masks during usual exposure vs. general use of FFP-2 masks) did not affect seroconversion rates of HCW during the first and the second pandemic wave.
Contact with SARS-CoV-2 infected household members was the most important risk factor for seroconversion among HCW. The strongest occupational risk factor was exposure to COVID-19 patients. During this pandemic, with heavy non-occupational exposure to SARS-CoV-2, the mask policy of HCIs did not affect the seroconversion rate of HCWs.
医护人员（HCW）从大流行开始就大量接触 SARS-CoV-2。我们旨在分析 HCW 中 SARS-CoV-2 血清转化的危险因素，特别强调各自医疗机构关于使用 FFP-2 口罩的建议。
我们从瑞士东南部（格劳宾登州）的 13 家具有不同口罩政策（IIR 外科口罩与 FFP-2 口罩）的医疗机构（HCI）招募 HCW。参与者的血清在第一次和第二次大流行波期间 6 个月后使用电化学发光免疫分析（ECLIA，罗氏诊断）分析 SARS-CoV-2 抗体的存在情况。我们使用在线问卷在两个时间点捕获 SARS-CoV-2 感染的危险因素。使用单变量和多变量逻辑回归评估个体 COVID-19 暴露、区域发病率和 FFP-2 口罩政策对血清转化率的影响。
在 2794 名 HCW 中的 99 名（3.5%）和 2315 名参与者中的 376 名（16.2%）在基线时检测到 SARS-CoV-2 抗体。在多变量分析中，血清转化率的最强关联是与已知 COVID-19 的家庭成员接触（基线时的优势比[OR]：19.82，95%置信区间[CI]：8.11-48.43，p<0.001；随访时的 OR：8.68，95%CI：6.13-12.29，p<0.001）。基线时的显著职业危险因素包括接触 COVID-19 患者（OR：2.79，95%CI：1.28-6.09，p=0.010）和 SARS-CoV-2 感染的同事（OR：2.50，95%CI：1.52-4.12，p<0.001）。在随访 6 个月后，非职业接触 SARS-CoV-2 感染个体（OR：2.54，95%CI：1.66-3.89，p<0.001）和相应 HCI 的当地 COVID-19 发病率（OR：1.98，95%CI：1.30-3.02，p=0.001）与血清转化率相关。医疗机构的口罩政策（通常接触时使用外科口罩与普遍使用 FFP-2 口罩）在第一次和第二次大流行波期间均未影响 HCW 的血清转化率。
与 SARS-CoV-2 感染的家庭成员接触是 HCW 血清转化的最重要危险因素。最强的职业危险因素是接触 COVID-19 患者。在这场大流行中，由于大量非职业接触 SARS-CoV-2，HCIs 的口罩政策并未影响 HCWs 的血清转化率。
