Here are the latest national Covid-19 trends, according to the U.S. Centers for Disease Control and Prevention (CDC) and major wastewater surveillance providers:
- New hospital admissions with Covid-19 have decreased 14%, from 1,100 admissions per day during the week ending April 6 to 900 admissions per day during the week ending April 13.
- Test positivity has decreased 3%, from 3.5% of Covid-19 tests returning positive results during the week ending April 6 to 3.4% of tests during the week ending April 13.
- Healthcare visits for influenza-like illness have decreased 10% between the week ending April 6 and the week ending April 13, and these visits are below the baseline for respiratory virus season.
- SARS-CoV-2 concentration in wastewater has decreased 18% between the week ending April 6 and the week ending April 13, and the national wastewater viral activity level is minimal, per the CDC.
- SARS-CoV-2 concentration in wastewater has decreased 5% between April 13 and April 20, per Biobot Analytics.
- SARS-CoV-2 concentration in wastewater has decreased 18% between April 8 and April 15, per WastewaterSCAN.
Covid-19 levels continue to be on the lower side across the U.S., as the country is in a lull between surges. But mild metrics from the CDC hide the fact that even during a lull, thousands of people are getting sick daily. And new variants are on the horizon, leading some scientists to warn of a potential wave this summer. Remember, while Covid-19 has been lumped in with seasonal, respiratory diseases like the flu and RSV, it’s less predictable — and more driven by our behavior — than these older diseases.
According to the CDC’s wastewater dashboard, SARS-CoV-2 activity levels both nationally and in most states are low or “minimal,” the lowest mark on the agency’s scale — and the lightest green color on its dashboard. However, it’s worth a reminder that the CDC’s viral activity level metrics are relatively new, and were designed to normalize the Omicron era of high Covid-19 spread even between waves of infections.
Wastewater dashboards with more longevity, such as Biobot Analytics’, present a different picture. According to Biobot’s reporting, SARS-CoV-2 levels have certainly come down significantly from this past winter’s surge, but are still several times higher than the low points we experienced in 2020 and 2021. WastewaterSCAN’s dashboard, which also dates back to 2021, shows similar results.
I typically don’t link to sources estimating infection rates from wastewater; as I explored for a recent article in Nature, wastewater data are complicated and there isn’t yet scientific consensus on how to use them in models. But sometimes these estimates are helpful as a comparison to the CDC’s “all-green” metrics. For example, last week, modeler JP Weiland estimated that the U.S. is currently seeing 200,000 new infections per day.
Weiland points to the FLiRT variants, a new group of coronavirus variants, as a potential driver of renewed disease spread — possibly starting as early as May. As Eric Topol explains in a recent Substack post, these variants have mutations in their spike proteins that will allow them to infect people more quickly than the current dominant lineage JN.1. It’s hard to tell whether these variants are different enough to spark a new wave and to identify exactly when they will take over, both Topol and Weiland point out, due to limited sequencing data.
Our hospitalization data are also about to get more limited: the CDC will stop requiring hospitals to report Covid-related metrics on April 30. While some hospitals will likely continue reporting voluntarily, this change will widen existing data gaps, making it more challenging to track the impact of future Covid-19 surges. The California State Health Department has already announced that it, too, will stop reporting any Covid-19 hospitalization data.
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