Using participatory, virologic, and wastewater surveillance systems, we estimated when and to what extent reported data of adult COVID-19 cases underestimated COVID-19 incidence in Germany. We also examined how case underestimation evolved over time. Our findings highlight how community-based surveillance systems can complement official notification systems for respiratory disease dynamics.
Keywords: COVID-19; Germany; SARS; SARS-CoV-2; coronavirus; coronavirus disease; incidence of notified cases; pandemic public health and social measures; participatory surveillance; respiratory infections; severe acute respiratory syndrome coronavirus 2; viruses; wastewater surveillance; zoonoses.