Incidence Rate of SARS-CoV-2 Infection Among Students Living in Dormitories - A Prospective Cohort Study With RT-PCR and SARS-CoV-2 Antibody Surveillance in a German University City (preprint)

Background: The role of educational facilities including schools and universities in the SARS-CoV-2 pandemic is heavily debated. Specifically, the risk of infection in student dormitories has not been studied. Methods: This cohort study monitors students living in dormitories in Bochum, Germany, throughout the winter term 2020/2021. Over the course of 4 months, participants were tested repeatedly for SARS-CoV-2 infection using RT-PCR from gargle samples and serological testing. An online questionnaire identified individual COVID-19-related risk factors. Findings: In total, 810 (46·5% female) students participated. Of these, 590 (72·8%) students participated in the final visit with serological follow up. The cross-sectional antibody prevalence was n=23 (2·8%) in November 2020 and n=29 (4·9%) in February 2021. Of 2,513 gargle samples analysed, 19 (0·8%) tested positive for SARS-CoV-2, corresponding to a total of 14 (2·4%) infections detected within the study period. All gargle samples available of cases with present infection were positive. The person-time incidence rate was 112·7 (95% CI: 54·11 – 207·2) per 100,000 person weeks. The expected incidence was calculated at 2·74% (RKI). This results in a standardized incidence ratio of 0·9 (95% CI 0·51-1·46, p=0·69). One possible infection cluster was detected by phylogenetic analysis (viral genome sequencing). Interpretation: Based on the results of the present study, students living in student dormitories do not appear to be major drivers of SARS-CoV-2 infections when appropriate measures are used. RT-PCR from gargle samples is a patient-friendly and scalable surveillance tool for the detection of SARS-CoV-2 infections. Funding Information: German Federal Ministry of Education and Research (BMBF). Declaration of Interests: The authors have no conflict of interest to disclose. Ethics Approval Statement: All participants provided written informed consent. The present study was approved by the Ethical Committee of the Medical Faculty, RuhrUniversity of Bochum (registration number: 20-7074).