COVID-19, Influenza, and RSV Wastewater Monitoring in the U.S. | Week of December 13, 2025

Summary: Week of 12/13/25

Biobot’s national wastewater network shows that the three major respiratory viruses—COVID-19, influenza, and RSV—continued to rise through the week ending December 13 (week 50). CDC clinical data echo this trend: hospitalizations for flu and RSV are increasing, with the sharpest rise seen in flu. COVID-19 hospitalizations remain steady for now, but are likely to follow wastewater trends and increase in the coming weeks.

The Bottom Line: As we head into peak holiday travel, respiratory viruses—especially flu—are surging. It’s not too late to get vaccinated. We still have months of elevated viral activity ahead, and vaccination remains one of the best tools to reduce the risk of severe illness.

National Outlook

COVID-19

National SARS-CoV-2 concentrations are increasing slightly.

Influenza

National influenza A concentrations are increasing while influenza B is decreasing.

RSV

National RSV concentrations are increasing.

Regional

The South

COVID-19: SARS-CoV-2 concentrations are increasing in the South.

Influenza: Influenza A concentrations are increasing in the South while influenza B is decreasing slightly.

RSV: RSV concentrations are increasing in the South.

The Midwest

COVID-19: SARS-CoV-2 concentrations are increasing in the Midwest.

Influenza: Influenza A concentrations are increasing in the Midwest while influenza B is holding steady.

RSV: RSV concentrations are increasing in the Midwest.

The Northeast

COVID-19: SARS-CoV-2 concentrations are decreasing slightly in the Northeast.

Influenza: Influenza A concentrations are increasing in the Northeast, while influenza B is holding steady.

RSV: RSV concentrations are increasing in the Northeast.

The West

COVID-19: SARS-CoV-2 concentrations are decreasing slightly in the West.

Influenza: Influenza A concentrations are increasing in the West, while influenza B concentrations are decreasing slightly.

RSV: RSV concentrations are increasing 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 December 13, 2025 (MMWR week 50). Clinical data for RSV, influenza, and COVID-19 from the Centers for Disease Control and Prevention are through December 6, 2025 (MMWR week 49).