Serological surveillance for SARS-CoV-2 antibodies among students, faculty and staff within a large university system during the pandemic.

Background: At the end of December 2019, the world faced severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), which led to the outbreak of coronavirus disease 2019 (COVID-19), associated with respiratory issues. This virus has shown significant challenges, especially for senior citizens, patients with other underlying illnesses, or those with a sedentary lifestyle. Serological tests conducted early on have helped identify how the virus is transmitted and how to curb its spread. The study hypothesis was that the rapid serological test for SARS-CoV-2 antibodies could indicate the immunoreactive profile during the COVID-19 pandemic in a university population.

Aim: To conduct active surveillance for serological expression of anti-SARS-CoV-2 antibodies in individuals within a university setting during the COVID-19 pandemic.

Methods: This sectional study by convenience sampling was conducted in a large university in Niteroi-RJ, Brazil, from March 2021 to July 2021. The study population consisted of students, faculty, and administrative staff employed by the university. A total of 3433 faculty members, 60703 students, and 3812 administrative staff were invited to participate. Data were gathered through rapid serological tests to detect immunoglobulin (Ig) M and IgG against SARS-CoV-2. The χ² or Fisher's exact test was used to conduct statistical analysis. A 0.20 significance level was adopted for variable selection in a multiple logistic regression model to evaluate associations.

Results: A total of 1648 individuals were enrolled in the study. The proportion of COVID-19 positivity was 164/1648 (9.8%). The adjusted logistic model indicate a positive association between the expression of IgM or IgG and age [odds ratio (OR) = 1.16, 95%CI: 1.02-1.31] (P < 0.0024), individuals who had been in contact with a COVID-19-positive case (OR = 3.49, 95%CI: 2.34-5.37) (P < 0.001), those who had received the COVID-19 vaccine (OR = 2.33, 95%CI: 1.61-3.35) (P < 0.001) and social isolation (OR = 0.59, 95%CI: 0.41-0.84) (P < 0.004). The likelihood of showing a positive result increased by 16% with every ten-year increment. Conversely, adherence to social distancing measures decreased the likelihood by 41%.

Conclusion: These findings evidenced that the population became more exposed to the virus as individuals discontinued social distancing practices, thereby increasing the risk of infection for themselves.