COVID Activity Rises Across America Again

COVID-19 activity is rising across the United States from a low baseline, a pattern that matters less for today’s hospital burden than for what it signals about transmission dynamics in the weeks ahead.

At a Glance

CDC reports COVID-19 activity is increasing nationally while overall respiratory illness and hospitalizations remain low.
Early indicators—especially wastewater—are trending upward, even when national “activity levels” still read very low or low.
Different baselines explain why one dashboard can flag “increasing” while another still labels levels “low.”
Wastewater trends tend to move before hospitalizations, making them useful for early action in clinics and households.

What the CDC is actually reporting

The Centers for Disease Control and Prevention’s respiratory-illness dashboard is unambiguous: COVID-19 activity is elevated and increasing nationally, though overall acute respiratory illness and hospitalizations remain low. That is a directional signal paired with a level assessment—spread is growing, but from a subdued floor compared with prior waves. CDC’s respiratory virus activity summary echoes the same two-part story: COVID-19 is rising nationally while seasonal influenza and RSV are quiet, consistent with late-summer epidemiology rather than winter respiratory stacking. For readers who lived through earlier surges, the crucial distinction is that “increasing” does not equal “severe”; it means momentum has turned upward.

Because clinical testing volumes remain modest and at-home tests are rarely reported, CDC and outside groups rely more heavily on early indicators—emergency department visits, sentinel outpatient reporting, and notably wastewater. Those systems are designed to catch trend inflections while hospitals are still calm. The tradeoff is interpretive: directional alerts can arrive when day-to-day life still looks normal, which is the point of early warning.

Why wastewater can rise while “activity levels” stay low

Two legitimate facts can coexist: national wastewater measurements can show clear week-over-week growth, and the CDC’s wastewater viral activity level (WVAL) can still classify the national picture as very low or low. The reason is methodology. WVAL compares current virus concentration at each site to that site’s own low levels over the prior 24 months—a period that includes sustained Omicron-era circulation—then bins results into very low, low, moderate, high, and very high. In other words, it is a baseline-relative index, not an absolute transmission meter. The national roll-up of those site-specific indices can therefore stay “low” even during a brisk ascent, until enough sites cross higher thresholds. CDC publishes the categorical cut points used for those bins; they are fixed, transparent thresholds applied consistently across viruses.

If you follow third-party platforms such as WastewaterSCAN, you may see stronger “high and rising” labels at the same moment national WVAL sits at low. That discrepancy reflects different reference frames, not a contradiction: WastewaterSCAN’s categorization relies on its own network’s historical distribution and trend definitions, while CDC’s WVAL anchors to each site’s two-year low baseline. For practical purposes, both perspectives are useful—one highlights early national momentum, the other situates today’s levels against the elevated background of recent years.

What early indicators tend to predict

Wastewater is not a parlor graph; it is a proxy for population infection burden that is independent of health care–seeking behavior, insurance coverage, or testing access. Multiple reviews and program evaluations have shown wastewater trends correlate with and often precede clinical metrics—particularly hospitalizations—by days to weeks. That lead time varies by sewershed size, sampling cadence, and population demographics, but the directionality is robust and has held across variant eras. For clinicians and health systems, an upswing in wastewater is a nudge to audit therapeutics on hand, refresh staff on test-to-treat pathways, and communicate with high-risk patients about timely antivirals if they fall ill. For households with vulnerable members, it can inform near-term decisions—masking in crowded indoor settings, ventilation, or planning vaccine appointments as updated formulations become available.

Emergency department visit data provide a second independent lens. When ED visits attributed to COVID-19 tick up from a very low baseline, they corroborate wastewater’s message: more people are falling ill enough to seek urgent care, albeit still a small fraction of all visits. That combination—rising wastewater plus rising ED proportion—describes the present pattern and is exactly what public-health surveillance is designed to detect before hospital strain appears.

How to read “increasing” without over-reading it

Surveillance vocabulary blends two ideas that lay readers understandably conflate: direction (up or down) and magnitude (low to very high). CDC’s public pages try to carry both at once—“increasing nationally” and “overall levels remain low”—but headlines tend to drop the second clause. The result is a recurring framing gap in respiratory season: warning systems emphasize velocity because it is actionable, while categorical dashboards emphasize level because it anchors risk perception. Both are defensible; they answer different questions. If your question is “Is the virus spreading more than last month?” look to trend lines. If it is “How does today compare to the worst periods of the past two years?” look to activity levels.

This distinction also explains regional heterogeneity. A nation can be “increasing” while most states are still very low and a handful show moderate or high activity; the average masks the tails. Those local deviations are where hospitals, schools, and employers feel operational impact first. They are also where targeted communication—reminders on updated vaccines, ventilation in congregate settings, and rapid access to antivirals—delivers the most benefit for the least disruption.

Mechanics and limits of the wastewater metrics

At the plant level, wastewater surveillance quantifies SARS-CoV-2 RNA in settled solids or influent and normalizes those measurements to account for flow and population, producing a concentration that can be compared over time. CDC applies quality-control filters before updating its dashboards to avoid spurious spikes from method changes or sample anomalies. The WVAL then classifies each site by comparing its current concentration to its own 24-month low baseline, smoothing out site-to-site idiosyncrasies and allowing aggregation across a heterogeneous network. That approach has virtues—stability, comparability, and resistance to one-off outliers—but it also means a community can see large percentage increases while remaining in a low category if the absolute level is still far below that site’s historical peaks.

No indicator is perfect. Wastewater’s lead time shortens in small sewersheds with intermittent sampling; storm events can dilute signals; population transience can blur attribution. These are known issues with established mitigations in modern programs. The upshot remains: when wastewater and ED signals rise together, they rarely do so by accident. They are measuring the same underlying phenomenon from different angles, and both now say COVID-19 transmission is gaining speed nationally from a low base.

Practical implications for the months ahead

Expect the dashboards to keep speaking two languages. Trend indicators will register momentum first; categorical levels will upgrade later if and when absolute concentrations breach thresholds. For decision-makers, the sensible posture is neither complacency nor alarmism: use the lead time. Health systems should audit Paxlovid and remdesivir pathways, nursing homes should revisit ventilation and visitation protocols, and individuals who are older or immunocompromised should make a plan for updated vaccination and prompt testing if symptomatic. The national picture can be calm while your zip code heats up; local wastewater and ED feeds are the best guides to near-term risk. The CDC’s message is clear and internally consistent: COVID-19 activity is increasing across the country, but from a low starting point. That is precisely when small, timely adjustments pay the biggest dividends.