One-year surveillance of SARS-CoV-2 transmission of the ELISA cohort: A model for population-based monitoring of infection risk
Christine Klein, Max Borsche, Alexander Balck, Bandik Föh, Johann Rahmöller, Elke Peters, Jan Knickmann, Miranda Lane, Eva‐Juliane Vollstedt, Susanne Elsner, Nadja Käding, Susanne Hauswaldt, Tanja Lange, Jennifer E. Hundt, Selina Lehrian, Julia Giese, Alexander Mischnik, Stefan Niemann, Florian P. Maurer, Susanne Homolka, Laura Paulowski, Jan Kramer, Christoph Twesten, Christian Sina, Gabriele Gillessen‐Kaesbach, Hauke Busch, Marc Ehlers, Stefan Taube, Jan Rupp, Alexander Katalinic
Abstract
With newly rising coronavirus disease 2019 (COVID-19) cases, important data gaps remain on (i) long-term dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates in fixed cohorts (ii) identification of risk factors, and (iii) establishment of effective surveillance strategies. By polymerase chain reaction and antibody testing of 1% of the local population and >90,000 app-based datasets, the present study surveilled a catchment area of 300,000 inhabitants from March 2020 to February 2021. Cohort (56% female; mean age, 45.6 years) retention was 75 to 98%. Increased risk for seropositivity was detected in several high-exposure groups, especially nurses. Unreported infections dropped from 92 to 29% during the study. "Contact to COVID-19-affected" was the strongest risk factor, whereas public transportation, having children in school, or tourism did not affect infection rates. With the first SARS-CoV-2 cohort study, we provide a transferable model for effective surveillance, enabling monitoring of reinfection rates and increased preparedness for future pandemics.