SARS-CoV-2 and Persistent Symptoms
Universities are unique environments with large populations, communal housing, and frequent attendance at large group events. However, the current prevalence of previous COVID-19 infection among university students, including symptomatic and asymptomatic illnesses, is unknown. Our objective, therefore, was to determine the prevalence of prior infection, risk factors for infection, and the prevalence of persistent symptoms following infection among university students.
Methods: This was a cross-sectional study conducted at a large public university between January 22 and March 22, 2021. We asked students about demographics, risk factors, and symptoms, and simultaneously tested their saliva for IgA antibodies against SARS-CoV-2.
To estimate the prevalence of previous infection, we adjusted our purposeful sample of a diverse student population for school year and age to resemble the composition of the entire student body and adjusted for susceptibility and imperfect specificity of the antibody test.
Univariate and multiple regression analysis was used to identify independent risk factors for infection, and the proportion of students with persistent symptoms after acute infection was determined.
Results: A total of 488 students completed the survey, 432 had a valid antibody result and 428 had both. The estimated prevalence of prior infection for 432 participants with valid antibody results was 41%. Of 145 students in our sample with a positive antibody test, 41.4% denied having a positive polymerase chain reaction (PCR) test for SARS-CoV-2 and likely had asymptomatic infection; in our adjusted analysis, we estimate that approximately 2/3 of students had asymptomatic infections.
Independent risk factors for infection included male gender, having a roommate with known symptomatic infection, and having two or fewer roommates. More frequent party and bar attendance was a univariate risk factor, but not in the multiple regression analysis. Of 122 students who reported a prior symptomatic infection, 14 (11.4%) reported persistent symptoms consistent with postacute COVID-19 a median of 132 days later.
Conclusions and Relevance: Prior COVID-19 infection, both symptomatic and asymptomatic, was common in a large university. Measures that could prevent the resurgence of infection when students return to campus include mandatory vaccination policies, mass surveillance testing and sewage testing for the SARS-CoV-2 antigen.