Insights Into Pandemic and Post-Pandemic Dynamics of Enteric Viruses in a Middle-Size City-Burgos, Spain-Using a Long-Term Wastewater Surveillance.

Wastewater-based epidemiology (WBE) has traditionally served as a tool for monitor pathogens, biomarkers, and consumption of pharmaceuticals or illicit drugs. In particular, enteric viruses have been extensively studied in wastewater due to their high titer of excretion. In this study, we investigated the presence of six clinically significant enteric viruses in twelve different areas of a Spanish middle-size city (Burgos), over a 3-year period from November 2021 to November 2024 (n = 600). Viral concentration was performed using an aluminum-based adsorption-precipitation method, followed by nucleic acid extraction and quantification via RT-qPCR. Process controls were included in each experiment to ensure assay accuracy and to calculate viral recovery rates, providing reliable estimates of enteric virus concentrations. The findings revealed that norovirus genogroup II was the most prevalent virus detected in 97.50% of the samples, followed by human astroviruses (90.00%), norovirus genogroup I (85.33%), rotavirus (83.83%), hepatitis E Virus (12.17%), and hepatitis A Virus (0.33%). Spatial heterogeneity in viral distribution was observed among sampling sites, along with temporal and seasonal variations between the COVID-19 pandemic and the post-pandemic periods. A positive correlation was found between enteric viruses and SARS-CoV-2, with both groups of viruses generally displaying stable co-existence. In our hands, this study represents the first long-term WBE analysis of enteric viruses conducted in a middle-sized city, providing valuable insights into the distribution, dynamics, and behavior of major enteric viruses across an extended temporal frame and different areas of the city, spanning both pandemic and post-pandemic contexts.