COVID-19 Activity Rises in Wastewater Across 27 States, CDC Data Show

COVID-19 activity is climbing across much of the United States heading into fall, with federal wastewater surveillance showing the virus growing or likely growing in 27 states, concentrated in the Northeast, Midwest and parts of the Northwest, even as overall levels remain low by historical standards.

The Centers for Disease Control and Prevention's wastewater tracker, which updates every Friday, estimates the virus is stable in roughly ten states and declining in the remainder, a shift from earlier in the month when growth was noted in as many as 35 states. Texas currently registers the only "very high" reading nationally, with California, Florida and Washington also among the states reporting elevated viral material in sewage. Public health officials rely on wastewater data because it can detect community spread before people develop symptoms severe enough to seek testing, giving forecasters an earlier signal than hospital admissions or laboratory-confirmed case counts alone.

The current pattern fits what infectious disease specialists have described as a now-familiar late-summer wave that tends to persist into early autumn before receding. Emergency department visits attributed to COVID-19 and test positivity rates have both ticked upward in the Northeast in recent weeks, according to CDC surveillance data, even as the agency continues to characterize national activity overall as low. Hospitalizations, the metric most closely tied to severe outcomes, have not risen at anywhere near the pace of wastewater signals, a divergence health officials attribute partly to broader population immunity built up through years of vaccination and prior infection.

A seasonal pattern, with new variants in the mix

CDC's variant tracking shows the current wave being driven by a shifting mix of Omicron descendants, consistent with the virus's pattern since 2022 of new sublineages periodically outcompeting their predecessors without necessarily producing more severe illness. The agency's national variant proportions page, part of the same wastewater surveillance system, tracks which lineages are gaining ground among the treatment plants that voluntarily submit sequencing data, information the agency uses to flag whether current vaccines remain well matched to circulating strains.

Public health messaging around the uptick has been notably quieter than in years immediately following the pandemic's peak, reflecting both reduced public appetite for COVID-specific guidance and a policy shift toward folding coronavirus surveillance into broader respiratory virus tracking alongside influenza and RSV. The CDC's combined dashboard now presents all three viruses side by side, a format change the agency adopted to reflect what officials describe as the pathogen's transition to an endemic, seasonal presence akin to other common respiratory illnesses.

Physicians interviewed by outlets tracking the data have generally counseled a familiar set of precautions: staying current on updated vaccines, testing before gathering in large groups, and staying home when symptomatic, rather than any change in behavior specific to this particular wave. Updated vaccine formulations targeting currently circulating strains have been available since late summer, though uptake has lagged well behind the pace seen in the first several years the shots were offered, according to CDC vaccination tracking figures.

The rise comes as schools and workplaces return to full indoor density following the summer months, a seasonal pattern that has coincided with respiratory virus upticks in each of the years since the pandemic began, regardless of which specific pathogen has been dominant in a given season. Wastewater treatment plants participating in the national surveillance network cover a large majority of the U.S. population, though coverage gaps remain in some rural areas, meaning the reported state-level trends can understate or overstate local conditions in places without a participating treatment facility nearby.

CDC has not changed any federal guidance in response to the current numbers and continues to recommend vaccination for people over six months old, with particular emphasis on adults over 65 and people with underlying health conditions that raise the risk of severe illness.