Seroprevalence of COVID-19 and Its Associated Factors Among Nigerian University Students: A Cross-Sectional Study

Universities were potential hubs for SARS-CoV-2 transmission in Nigeria; however, empirical data on the infection burden among students have been limited. The study assessed the seroprevalence of SARS‑CoV‑2 and associated factors among undergraduates at a public University to inform educational and public health policy. The study used a cross-sectional design and was conducted among systematically sampled students at the University of Benin City, Nigeria, between February and December 2022. Sociodemographic and behavioural data were collected using a structured tool. Nasal swabs and venous blood were tested for SARS‑CoV‑2 antigen and IgM/IgG antibodies using rapid diagnostic assays. Seroprevalence was estimated with 95% Confidence Intervals (CIs), and associated factors were explored using logistic regression, with the findings presented as adjusted odds ratios (aORs). Among 677 participants (mean age, 21.5 years), all antigen tests were negative. Of 670 valid serological results, 79.6% tested positive for IgG and 14.0% for IgM. IgG positivity was independently associated with the use of mixed transportation (aOR 2.32; 95% CI: 1.31-4.09) and attendance at religious gatherings twice a week (aOR 1.82; 95% CI: 1.07-3.10). IgM positivity was higher among students residing in rural settings and lower among those using mixed transportation. In conclusion, no active COVID‑19 infection was detected, but most students had evidence of past infection during the post‑omicron period. These findings underscore the substantial cumulative exposure among young adults and highlight the importance of strengthening prevention strategies in university settings.