Chicago Respiratory Virus Concentrations in Wastewater Since 2022

Weekly measurements of SARS-CoV-2, RSV, and influenza virus concentrations from seven sewershed sites in Chicago since February 2022. The Chicago Department of Public Health aggregates and publishes this data, which is updated weekly to track disease trends. It replaces a previous COVID-19 specific dataset.

Use Cases

• Modeling the relationship between `wkavg_val` (weekly average concentration) and `pathogen` type across different `sitename` locations.
• Analyzing seasonal trends by joining `week_start` and `season` columns to identify peak virus activity periods.
• Forecasting `target_wkavg_concentration` for future weeks using historical `mmwr_week` and `year` data.
• Comparing virus prevalence between individual sites (e.g., `siteno`) and the aggregated 'All sites' view to assess geographic spread.

Strengths

• Multi-pathogen coverage including SARS-CoV-2, RSV, and influenza A/B since February 2022.
• Data is collected from seven distinct `sitename` locations, providing geographic granularity within Chicago.
• Weekly update frequency ensures the data remains current for surveillance purposes.

Limitations

• Sample size is limited to approximately two samples per site per week, which may affect statistical power for short-term analysis.
• The 'All sites' aggregate row requires careful handling to avoid double-counting when performing analyses across sites.
• Geographic coverage is restricted to the Chicago sewer system, limiting generalizability to other regions.

Provenance

Source

Chicago Department of Public Health, published via data.cityofchicago.org.

Collection Method

Virus concentration measurements from wastewater samples collected at seven sewershed sites.

Time Range

February 2022 to present (ongoing).

Freshness

Updated weekly, with a last updated date of 2026-04-03.

Geography

Chicago, Illinois, USA (seven specific sewer system sites).