TY - JOUR T1 - Seroprevalence of antibodies to SARS-CoV-2 in healthcare workers: a cross-sectional study JF - BMJ Open JO - BMJ Open DO - 10.1136/bmjopen-2020-043584 VL - 11 IS - 2 SP - e043584 AU - Joseph E Ebinger AU - Gregory J Botwin AU - Christine M Albert AU - Mona Alotaibi AU - Moshe Arditi AU - Anders H Berg AU - Aleksandra Binek AU - Patrick Botting AU - Justyna Fert-Bober AU - Jane C Figueiredo AU - Jonathan D Grein AU - Wohaib Hasan AU - Mir Henglin AU - Shehnaz K Hussain AU - Mohit Jain AU - Sandy Joung AU - Michael Karin AU - Elizabeth H Kim AU - Dalin Li AU - Yunxian Liu AU - Eric Luong AU - Dermot P B McGovern AU - Akil Merchant AU - Noah Merin AU - Peggy B Miles AU - Margo Minissian AU - Trevor Trung Nguyen AU - Koen Raedschelders AU - Mohamad A Rashid AU - Celine E Riera AU - Richard V Riggs AU - Sonia Sharma AU - Sarah Sternbach AU - Nancy Sun AU - Warren G Tourtellotte AU - Jennifer E Van Eyk AU - Kimia Sobhani AU - Jonathan G Braun AU - Susan Cheng Y1 - 2021/02/01 UR - http://bmjopen.bmj.com/content/11/2/e043584.abstract N2 - Objective We sought to determine the extent of SARS-CoV-2 seroprevalence and the factors associated with seroprevalence across a diverse cohort of healthcare workers.Design Observational cohort study of healthcare workers, including SARS-CoV-2 serology testing and participant questionnaires.Settings A multisite healthcare delivery system located in Los Angeles County.Participants A diverse and unselected population of adults (n=6062) employed in a multisite healthcare delivery system located in Los Angeles County, including individuals with direct patient contact and others with non-patient-oriented work functions.Main outcomes Using Bayesian and multivariate analyses, we estimated seroprevalence and factors associated with seropositivity and antibody levels, including pre-existing demographic and clinical characteristics; potential COVID-19 illness-related exposures; and symptoms consistent with COVID-19 infection.Results We observed a seroprevalence rate of 4.1%, with anosmia as the most prominently associated self-reported symptom (OR 11.04, p<0.001) in addition to fever (OR 2.02, p=0.002) and myalgias (OR 1.65, p=0.035). After adjusting for potential confounders, seroprevalence was also associated with Hispanic ethnicity (OR 1.98, p=0.001) and African-American race (OR 2.02, p=0.027) as well as contact with a COVID-19-diagnosed individual in the household (OR 5.73, p<0.001) or clinical work setting (OR 1.76, p=0.002). Importantly, African-American race and Hispanic ethnicity were associated with antibody positivity even after adjusting for personal COVID-19 diagnosis status, suggesting the contribution of unmeasured structural or societal factors.Conclusion and relevance The demographic factors associated with SARS-CoV-2 seroprevalence among our healthcare workers underscore the importance of exposure sources beyond the workplace. The size and diversity of our study population, combined with robust survey and modelling techniques, provide a vibrant picture of the demographic factors, exposures and symptoms that can identify individuals with susceptibility as well as potential to mount an immune response to COVID-19. ER -