RT Journal Article
SR Electronic
T1 SARS-CoV-2 seroprevalence in healthcare workers of a Swiss tertiary care centre at the end of the first wave: a cross-sectional study
JF BMJ Open
JO BMJ Open
FD British Medical Journal Publishing Group
SP e049232
DO 10.1136/bmjopen-2021-049232
VO 11
IS 7
A1 Sylvain Meylan
A1 Urania Dafni
A1 Frederic Lamoth
A1 Zoi Tsourti
A1 Michael A Lobritz
A1 Jean Regina
A1 Philippe Bressin
A1 Laurence Senn
A1 Bruno Grandbastien
A1 Cyril Andre
A1 Craig Fenwick
A1 Valerie D'Acremont
A1 Antony Croxatto
A1 Isabelle Guilleret
A1 Gilbert Greub
A1 Oriol Manuel
A1 Thierry Calandra
A1 Giuseppe Pantaleo
A1 Catherine Lazor-Blanchet
A1 ,
YR 2021
UL http://bmjopen.bmj.com/content/11/7/e049232.abstract
AB Objective To assess the SARS-CoV-2 transmission in healthcare workers (HCWs) using seroprevalence as a surrogate marker of infection in our tertiary care centre according to exposure.Design Seroprevalence cross-sectional study.Setting Single centre at the end of the first COVID-19 wave in Lausanne, Switzerland.Participants 1874 of 4074 responders randomly selected (46% response rate), stratified by work category among the 13 474 (13.9%) HCWs.Main outcome measures Evaluation of SARS-CoV-2 serostatus paired with a questionnaire of SARS-CoV-2 acquisition risk factors internal and external to the workplace.Results The overall SARS-CoV-2 seroprevalence rate among HCWs was 10.0% (95% CI 8.7% to 11.5%). HCWs with daily patient contact did not experience increased rates of seropositivity relative to those without (10.3% vs 9.6%, respectively, p=0.64). HCWs with direct contact with patients with COVID-19 or working in COVID-19 units did not experience increased seropositivity rates relative to their counterparts (10.4% vs 9.8%, p=0.69 and 10.6% vs 9.9%, p=0.69, respectively). However, specific locations of contact with patients irrespective of COVID-19 status—in patient rooms or reception areas—did correlate with increased rates of seropositivity (11.9% vs 7.5%, p=0.019 and 14.3% vs 9.2%, p=0.025, respectively). In contrast, HCWs with a suspected or proven SARS-CoV-2-infected household contact had significantly higher seropositivity rates than those without such contacts (19.0% vs 8.7%, p<0.001 and 42.1% vs 9.4%, p<0.001, respectively). Finally, consistent use of a mask on public transportation correlated with decreased seroprevalence (5.3% for mask users vs 11.2% for intermittent or no mask use, p=0.030).Conclusions The overall seroprevalence was 10% without significant differences in seroprevalence between HCWs exposed to patients with COVID-19 and HCWs not exposed. This suggests that, once fully in place, protective measures limited SARS-CoV-2 occupational acquisition within the hospital environment. SARS-CoV-2 seroconversion among HCWs was associated primarily with community risk factors, particularly household transmission.Data are available upon reasonable request. The data related to this study can be requested at CHUV to Dr Sylvain Meylan (Sylvain.Meylan@chuv.ch). Such transfer is submitted to the Human Research and the Data Protection Swiss Legislation and, accordingly, to the signature of a Data Sharing and User Agreement.