RT Journal Article SR Electronic T1 SARS-CoV-2 seroprevalence and asymptomatic viral carriage in healthcare workers: a cross-sectional study JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 1089 OP 1094 DO 10.1136/thoraxjnl-2020-215414 VO 75 IS 12 A1 Adrian Shields A1 Sian E Faustini A1 Marisol Perez-Toledo A1 Sian Jossi A1 Erin Aldera A1 Joel D Allen A1 Saly Al-Taei A1 Claire Backhouse A1 Andrew Bosworth A1 Lyndsey A Dunbar A1 Daniel Ebanks A1 Beena Emmanuel A1 Mark Garvey A1 Joanna Gray A1 I Michael Kidd A1 Golaleh McGinnell A1 Dee E McLoughlin A1 Gabriella Morley A1 Joanna O'Neill A1 Danai Papakonstantinou A1 Oliver Pickles A1 Charlotte Poxon A1 Megan Richter A1 Eloise M Walker A1 Kasun Wanigasooriya A1 Yasunori Watanabe A1 Celina Whalley A1 Agnieszka E Zielinska A1 Max Crispin A1 David C Wraith A1 Andrew D Beggs A1 Adam F Cunningham A1 Mark T Drayson A1 Alex G Richter YR 2020 UL http://thorax.bmj.com/content/75/12/1089.abstract AB Objective To determine the rates of asymptomatic viral carriage and seroprevalence of SARS-CoV-2 antibodies in healthcare workers.Design A cross-sectional study of asymptomatic healthcare workers undertaken on 24/25 April 2020.Setting University Hospitals Birmingham NHS Foundation Trust (UHBFT), UK.Participants 545 asymptomatic healthcare workers were recruited while at work. Participants were invited to participate via the UHBFT social media. Exclusion criteria included current symptoms consistent with COVID-19. No potential participants were excluded.Intervention Participants volunteered a nasopharyngeal swab and a venous blood sample that were tested for SARS-CoV-2 RNA and anti-SARS-CoV-2 spike glycoprotein antibodies, respectively. Results were interpreted in the context of prior illnesses and the hospital departments in which participants worked.Main outcome measure Proportion of participants demonstrating infection and positive SARS-CoV-2 serology.Results The point prevalence of SARS-CoV-2 viral carriage was 2.4% (n=13/545). The overall seroprevalence of SARS-CoV-2 antibodies was 24.4% (n=126/516). Participants who reported prior symptomatic illness had higher seroprevalence (37.5% vs 17.1%, χ2=21.1034, p<0.0001) and quantitatively greater antibody responses than those who had remained asymptomatic. Seroprevalence was greatest among those working in housekeeping (34.5%), acute medicine (33.3%) and general internal medicine (30.3%), with lower rates observed in participants working in intensive care (14.8%). BAME (Black, Asian and minority ethnic) ethnicity was associated with a significantly increased risk of seropositivity (OR: 1.92, 95% CI 1.14 to 3.23, p=0.01). Working on the intensive care unit was associated with a significantly lower risk of seropositivity compared with working in other areas of the hospital (OR: 0.28, 95% CI 0.09 to 0.78, p=0.02).Conclusions and relevance We identify differences in the occupational risk of exposure to SARS-CoV-2 between hospital departments and confirm asymptomatic seroconversion occurs in healthcare workers. Further investigation of these observations is required to inform future infection control and occupational health practices.