Longitudinal trends in the endemic symptomatic burden of COVID-19: Insights from community-based participatory virological surveillance in the Netherlands, November 2020 - April 2025

Objectives: To analyze changes over time in symptomatology and symptom burden of SARS-CoV-2 infected individuals. Methods: Data from symptomatic individuals from Infectieradar, an online community-based, participatory surveillance platform in the Netherlands, were analyzed (November 2020 - April 2025). Weekly questionnaires collected self-reported data on SARS-CoV-2 testing, health score (scale: 0-100), medication use, and healthcare visits. Longitudinal trends were evaluated using logistic regression models adjusted for age, sex, and comorbidities. Results: During 4.5 years, 18,600 participants reported a positive SARS-CoV-2 test at least once. Upper respiratory symptoms became more prominent over time, and loss of smell and taste less. The self-reported health score and the proportion of symptomatic SARS-CoV-2-positive individuals with a high number of symptoms (more than 10 symptoms) remained relatively stable over time (October 2022 - April 2025), with a health impact comparable to influenza virus infections (n = 768). Conclusions: The findings suggest that the clinical presentation of COVID-19 has evolved toward upper respiratory symptoms. Despite shifting symptoms, the impact on reported well-being in this population was remarkably stable, without a significantly lower endemic symptomatic burden. The health impact of COVID-19 is more comparable to influenza than to other common respiratory infections.