- Ebinger, Joseph E;
- Botwin, Gregory J;
- Albert, Christine M;
- Alotaibi, Mona;
- Arditi, Moshe;
- Berg, Anders H;
- Binek, Aleksandra;
- Botting, Patrick;
- Fert-Bober, Justyna;
- Figueiredo, Jane C;
- Grein, Jonathan D;
- Hasan, Wohaib;
- Henglin, Mir;
- Hussain, Shehnaz K;
- Jain, Mohit;
- Joung, Sandy;
- Karin, Michael;
- Kim, Elizabeth H;
- Li, Dalin;
- Liu, Yunxian;
- Luong, Eric;
- McGovern, Dermot PB;
- Merchant, Akil;
- Merin, Noah;
- Miles, Peggy B;
- Minissian, Margo;
- Nguyen, Trevor Trung;
- Raedschelders, Koen;
- Rashid, Mohamad A;
- Riera, Celine E;
- Riggs, Richard V;
- Sharma, Sonia;
- Sternbach, Sarah;
- Sun, Nancy;
- Tourtellotte, Warren G;
- Van Eyk, Jennifer E;
- Sobhani, Kimia;
- Braun, Jonathan G;
- Cheng, Susan
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.