High prevalence of previous infection with SARS-CoV-2 and persistent symptoms at a large university

Abstract Importance Universities are unique settings with large populations, congregate housing, and frequent attendance of events in large groups. However, the prevalence of previous infection with SARS-CoV-2 in university students, including symptomatic and asymptomatic disease, is unknown. Objective To determine the prevalence of previous infection, risk factors for infection, and the prevalence of persistent symptoms following infection among university students. Design This was a cross-sectional study that surveyed students about demographics, risk factors, and symptoms, and simultaneously tested their saliva for IgA antibodies to SARS-CoV-2. To estimate the prevalence of previous infection we adjusted our intentional sample of a diverse student population for year in school and age to resemble the composition of the entire student body, and adjusted for the imperfect sensitivity and specificity of the antibody test. Univariate and multivariate analysis was used to identify independent risk factors for infection. Setting A large public university in Athens, Georgia between January 22 and March 22, 2021. Participants Undergraduate and graduate students; 488 completed the survey, 432 had a valid antibody result. and 428 had both. Exposure Previous infection with SARS-CoV-2 based on measurement of IgA antibodies in saliva and adjustment for sample characteristics and test accuracy. Main Outcomes and Measures The primary outcome was the estimated prevalence of previous infection with SARS-CoV-2. Secondary outcomes were independent risk factors for infection, and the prevalence of persistent symptoms among persons reporting a previous symptomatic infection. Results The estimated prevalence of previous infection for 432 participants with valid antibody results was between 41% and 42%. Independent risk factors for infection included male sex, having a roommate with a known symptomatic infection, and having 2 or fewer roommates. More frequent attendance of parties and bars was a univariate risk factor, but not in the multivariate analysis. Of 122 students reporting a previous symptomatic infection, 14 (11.4%) reported persistent symptoms a median of 132 days later. Conclusions and Relevance Previous infection with SARS-CoV-2, both symptomatic and asymptomatic, was common at a large university. Measures that could prevent resurgence of the infection when students return to campus include mandatory vaccination policies, mass surveillance testing, and testing of sewage for antigen to SARS-CoV-2. Key Points Question What is the prevalence of previous infection with SARS-CoV-2 and the prevalence of persistent symptoms in university students? Findings In this sample of 432 students who provided saliva for IgA antibodies, we estimate that 41% to 42% had evidence of previous infection. Of 122 reporting a previous symptomatic infection, 14 (11%) were still symptomatic a median of 132 days later. Meaning Symptomatic and asymptomatic infections with SARS-CoV-2 are common among university students, and a significant percentage had persistent symptoms over a long duration.