Summary: Week of 9/20/25
Biobot’s national wastewater network shows that COVID-19 is continues to decrease in week 38 (through September 20, 2025). Influenza A and RSV are holding steady at very low levels, while influenza B is fluctuating slightly at low levels. National hospitalizations for COVID-19 are also decreasing, currently at 2.3 per 100,000 people in week 37 (through September 13). RSV hospitalizations are holding steady at very low levels, currently 0 per 100,000 people while flu hospitalizations have not been updated on the CDC website since May 3rd.
The Bottom Line: COVID-19 activity continues to decrease, signalling that we are making our way out of this summer wave, while flu and RSV remain very low.
National Outlook
COVID-19
National SARS-CoV-2 concentrations are decreasing.
Influenza
National flu A concentrations are holding steady at very low levels, while influenza B is fluctuating slightly at very low levels.
RSV
National RSV concentrations are holding steady at very low levels.
Regional
The South
COVID-19: SARS-CoV-2 concentrations are decreasing in the South.
Influenza: Influenza A concentrations are holding steady at very low levels in the South, while influenza B concentrations are slightly fluctuating at very low levels.
RSV: RSV concentrations are holding steady at very low levels in the South.
The Midwest
COVID-19: SARS-CoV-2 concentrations are decreasing in the Midwest.
Influenza: Influenza A and B concentrations are holding steady at very low levels in the Midwest.
RSV: RSV concentrations are holding steady at very low levels in the Midwest.
The Northeast
COVID-19: SARS-CoV-2 concentrations are decreasing in the Northeast.
Influenza: Influenza A & B are holding steady at very low levels in the Northeast.
RSV: RSV concentrations are holding steady at very low levels in the Northeast.
The West
COVID-19: SARS-CoV-2 concentrations are decreasing in the West.
Influenza: Influenza A and B concentrations are holding steady at very low levels in the West.
RSV: RSV concentrations are holding steady at very low levels in the West.
Footnotes:
We continue to monitor the evolving H5N1 influenza virus situation, and can now test samples specifically for H5 (including H5N1) — see our blog here and please reach out to hello@biobot.io if interested. A quick reminder that Biobot’s influenza A assay described in this report includes the H5N1 influenza subtype, which is an influenza A virus, but does not distinguish between the different subtypes of influenza A (e.g. H5N1 vs H1N1). We will share any important updates as we have them via Bluesky and in the risk reports.
Wastewater data from Biobot Analytics for RSV, influenza, and SARS-CoV-2 are through September 20, 2025 (MMWR week 38). Clinical data for RSV, influenza, and COVID-19 are from the Centers for Disease Control and Prevention. Updates to clinical data are through September 13, 2025 (MMWR week 37).