COVID-19 rapid antigen tests as a surveillance tool for population-wide pandemic monitoring

Effective mitigation of the COVID-19 pandemic depended on timely and reliable indicators generated by robust surveillance systems. While monitoring of disease burden and transmission relied largely on established surveillance tools, antigen rapid diagnostic tests (Ag-RDTs) were primarily used for individual diagnostics and to supplement molecular testing capacity. Their potential as a population-level surveillance tool, however, has remained insufficiently explored. We performed bivariate and multivariate time series analyses on a previously unanalyzed dataset containing 14 million population-wide Ag-RDT results from Germany spanning December 2021 to January 2023. The ratio of positive Ag-RDTs was compared with the 7-day incidence, 7-day incidence of hospitalizations, and ratio of occupied ICU beds. Results showed strong temporal correlations, with Ag-RDTs preceding pandemic indicators by 1–3 days, demonstrating significant predictive power. Our findings indicate that Ag-RDTs can serve as effective surveillance tools to support mitigation and monitoring of future pandemics, enabling more timely public health responses.