COVID-19, Influenza, and RSV Wastewater Monitoring in the U.S. | Week of March 28, 2026

Summary: Week of 3/28/26

Biobot’s national network shows that SARS-CoV-2, influenza A, and RSV are all decreasing nationally. Influenza B, though, is the exception—it’s increasing nationally. We’ve seen substantially more influenza B transmission this season compared to last year’s.

The Bottom Line: Most respiratory viruses are in decline, but influenza B signals continue to increase, particularly in the Northeast and West. High-risk individuals—older adults, young children, and those with underlying health conditions—should consider continuing to layer protections including masking in crowded indoor spaces, improving ventilation, and using rapid tests when symptomatic (which are available over the counter at pharmacies).

National Outlook

COVID-19

Nationally, SARS-CoV-2 is decreasing.

Influenza

Nationally, influenza A is decreasing while influenza B is increasing again.

RSV

Nationally, RSV is decreasing.

Regional Outlook

The South

COVID-19: SARS-CoV-2 is holding steady in the South.

Influenza: Influenza A is decreasing in the South, while influenza B is mostly holding steady.

RSV: RSV is decreasing in the South.

The Midwest

COVID-19: SARS-CoV-2 is decreasing in the Midwest.

Influenza: Influenza A is decreasing in the Midwest, while influenza B is increasing.

RSV: RSV is decreasing in the Midwest.

The Northeast

COVID-19: SARS-CoV-2 is holding steady in the Northeast.

Influenza: Influenza A is decreasing in the Northeast, while influenza B is increasing.

RSV: RSV is decreasing in the Northeast.

The West

COVID-19: SARS-CoV-2 is decreasing in the West.

Influenza: Influenza A is decreasing in the West, while influenza B is increasing.

RSV: RSV is decreasing in the West.

Footnotes:

We continue to monitor the evolving H5N1 influenza virus situation, and can now test samples specifically for H5 (including H5N1) — 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. 

Wastewater data from Biobot Analytics for RSV, influenza, and SARS-CoV-2 are through March 28, 2026 (MMWR week 12).