High Seroprevalence Against SARS-CoV-2 Among Faculty of Medicine and Health Sciences Personnel and Students of the University of Alcalá, Spain: Contributing Factors

PURPOSE: Seroprevalence against SARS-CoV-2 within university systems is poorly studied, making evidence-based discussions of educational system reopening difficult. Moreover, few studies evaluate how antibodies against SARS-CoV-2 are maintained over time. We assessed serological response against the SARS-CoV-2 virus among our university students and staff. PATIENTS AND METHODS: In this prospective cohort study, seroprevalence was determined in 705 randomly selected volunteers, members of the Faculty of Medicine and Health Sciences of the University of Alcalá, using a chemiluminescent Siemens’ SARS-CoV-2 immunoassay for total antibodies. Positive samples were tested for IgG and IgM/IgA using VIRCLIA(®) MONOTEST (Vircell). A first analysis took place during June 2020, and in those testing positive, a determination of secondary outcomes was performed in November 2020. RESULTS: A total of 130 subjects showed anti-SARS-CoV-2 antibodies (18.5%, 95% CI, 15.8–21.5%). Of these, IgM/IgA was positive in 27 and indeterminate in 19; IgG was positive in 118, indeterminate in 1. After 23 weeks, among 102 volunteers remeasured, IgG became undetectable in 6. Presence of antibodies was associated, in multivariable logistic regression, with exposure to infected patients (31.3%) [OR 1.84, 95% CI, 1.14–2.96; P = 0.012], presence of COVID-19 symptoms (52.4%) [OR 6.88, 95% CI, 4.28–11.06; P < 0.001], and confirmed earlier infection (82.9%) [OR 11.87, 95% CI, 4.26–33.07; P < 0.001]. CONCLUSIONS: The faculty of medicine and health sciences personnel and students of our university showed a high infection rate for SARS-CoV-2 during 2020 associated with providing clinical care to infected patients. This emphasizes the importance of the performance of continuous surveillance methods of the most exposed health personnel, including health science students.