Non-occupational and occupational factors associated with specific SARS-CoV-2 antibodies among Hospital Workers – a multicentre cross-sectional study

Abstract

Background Protecting healthcare workers (HCW) from Coronavirus Disease-19 (COVID-19) is critical to preserve the functioning of healthcare systems. We therefore assessed seroprevalence and identified risk factors for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) seropositivity in this population. Methods Between June 22nd and August 15th 2020, employees from healthcare institutions in Northern/Eastern Switzerland were screened for SARS-CoV-2 antibodies. We recorded baseline characteristics, non-occupational and occupational risk factors. We used pairwise tests of associations and multivariable logistic regression to identify factors associated with seropositivity. Findings Among the 4664 included HCW from 23 healthcare facilities, 139 (3%) were seropositive. Non-occupational exposures independently associated with seropositivity were contact with a COVID-19 positive household (adjusted OR=54, 95%-CI: 31-97) and stay in a COVID 19 hotspot (aOR=2.2, 95%-CI: 1.1-3.9). Blood group 0 vs. non-0 (aOR=0.4, 95%-CI: 0.3-0.7), active smoking (aOR=0.5, 95%-CI: 0.3-0.9) and living with children <12 years (aOR=0.3, 95%-CI: 0.2-0.6) were associated with decreased risk. Occupational risk factors were close contact to COVID-19 patients (aOR=2.8, 95%-CI: 1.5-5.5), exposure to COVID-19 positive co-workers (aOR=2.0, 95%-CI: 1.2-3.1), poor knowledge of standard hygiene precautions (aOR=2.0, 95%-CI: 1.3-3.2), and frequent visits to the hospital canteen (aOR=1.9, 95%-CI: 1.2-3.1). Interpretation We identified several modifiable factors associated with SARS-CoV-2 seropositivity among our HCW. Living with COVID-19 positive households showed by far the strongest association. The lower risk among those living with children, even after correction for multiple confounders, is remarkable and merits further study. Funding Swiss National Sciences Foundation, Federal Office of Public Health, Health Department Canton of St. Gallen

Use of respirator vs. surgical masks in healthcare personnel and its impact on SARS-CoV-2 acquisition – a prospective multicentre cohort study

“…age, sex, profession) were similar between the total HCW population (from the largest participating institution) and the cohort population. 20 To conclude, FFP2 use outside of AGPs is associated with a reduced risk of SARS-CoV-2 acquisition for HCW with high COVID-19 exposure, while those with only sporadic or no known contact do not seem to benefit. The effect size should be interpreted in the context of the global COVID-19 risk for HCW, which is driven by exposure to positive household contacts.…”

“…Employees registered online and provided electronic consent. Enrolment took place from June 22 nd to August 15 th 2020, between the end of the first COVID-19 wave in Switzerland and the surge of the second wave; 20 data were analysed up to March 9 th 2021, when the second wave had abated ( Figure 1 ). The study was approved by the ethics committee of Eastern Switzerland (#2020-00502).…”

“…Samples were analysed with an electro-chemiluminescence immunoassay (ECLIA, Roche Diagnostics, Rotkreuz, Switzerland, detection of total antibodies directed against the nucleocapsid-(N)-protein of SARS-CoV-2), as described elsewhere. 20…”

“…The model included COVID-19 exposures reported in any of the three weekly questionnaires submitted before the end of each time interval as well as the cumulative number of negative swabs up to an interval’s end (to account for different testing behaviour) as time-dependent co-variables, and answers from the baseline and follow-up questionnaire (including mask type) as time-independent co-variables. These variables were a priori chosen from the baseline questionnaire, 20 based on their expected potential to confound the association between mask use and risk for SARS-CoV-2 acquisition. Cantons and institutions were included as cluster terms.…”

Healthcare Institutions’ Recommendation Regarding the Use of FFP-2 Masks and SARS-Cov-2 Seropositivity Among Healthcare Workers – A Multicenter Longitudinal Cohort Study

“…From the beginning of the pandemic, several studies have investigated the risk for HCW for infections with SARS-CoV-2. While some studies showed low infection rates among HCW indicating that the implemented protection measures were effective, (1)(2)(3)(4) others studies revealed high infection rates among HCW (5)(6)(7)(8)(9)(10)(11). The most frequently identi ed risk factors for transmission of SARS-CoV-2 to HCW include working at dedicated COVID-19 units (6, 7), having either direct contact with infected patients (8,9), or infected co-workers (9,11) and being exposed to infected household members(8, 10,11).…”