Upcoming change to the Respiratory Virus Wastewater Surveillance Dataset.

Concentrations of respiratory viruses in the Chicago sewer system as measured at seven sewershed sites since February 2022. In addition to SARS-CoV-2 (the virus that causes COVID-19), concentration data is also available for Respiratory Syncytial Virus (RSV), and influenza virus (types A and B). Generally, two samples are collected from each site during each week of the year. Concentration data reflect within-site and overall averages of this data each week. Because respiratory viruses are shed in human feces, tracking this data can help predict changes in disease trends and better understand the epidemiology of these common respiratory viruses in Chicago. Please note that one of the "sites" listed is "All sites," which combines the individual sites. Care should be taken when summing or otherwise aggregating rows to avoid double counting. These data are updated weekly and displayed on the Chicago Department of Public Health’s Respiratory Illness Dashboard. This dataset replaces COVID-19 Wastewater Detection, which will no longer be updated. See https://data.cityofchicago.org/stories/s/Wastewater-Surveillance-Datasets-3-5-2025/sihu-d8va for more information.

Concentrations of the SARS-CoV-2 virus (the COVID-19 virus) gene in the Chicago sewer system, as measured at eight sewershed sites. These sites represent catchment areas that describe wastewater from 319,700 Chicagoans as of January 2023. Because SARS-CoV-2 is shed in human feces, this method can be used to estimate changes in COVID-19 at different times and locations across Chicago. While the data in this dataset do not indicate how many people were infected with SARS-CoV-2, differences in the the normalized_n1 indicate whether the proportion of individuals at the site who are shedding that virus has changed.

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