You keep getting those flu shot reminders for a reason—we're still in the thick of sick season.
According to new info released by the CDC on Friday, January 24, positive tests for influenza increased nationwide by 25% during the week of January 18. Emergency room visits for the flu are also "very high," and influenza A has been found to be increasing in wastewater samples throughout the U.S.
That said, this data is different and much less specific from the weekly reports the CDC usually provides about the flu.
Related: Flu Levels Are "Very High" and "High" in 41 States After Holiday Surge
Why These Flu Stats Are Different Than Before
Typically, the CDC releases a weekly FluView report that offers a detailed look at seasonal influenza activity, including the types of the virus found, hospitalization stats, mortality rate, and cases by state. The last time the CDC provided the FluView was for the week ending on January 11, 2025.
Since then, the Trump administration has put a halt on all scientific communication from federal health agencies until at least February 1. As a result, the CDC has changed gears by including these latest flu stats in a "Respiratory Virus Activity Levels" report, which also shares data on nationwide COVID-19, RSV, and other acute respiratory illness cases.
Still, experts are worried about the new lack of specificity.
"We look at data like this to see what additional resources we might need to bring in," Dr. Aaron Glatt, chief of infectious diseases at Mount Sinai South Nassau in New York, told NBC News. "It gives us a certain sense of what will happen." Without precise state-by-state or strain-specific trends, hospitals and health care physicians are operating with more blind spots.
"One piece of data in a huge data stream is probably not the end of the world,” Glatt added. “However, I am concerned if this continues. We do need to know, are we going up? Or are we going down?"
Related: New OTC Tests Can Check for Both COVID & the Flu
What the Latest State-By-State Flu Activity Shows
U.S. Wastewater sample map of influenza A as of January 18, 2025CDC
For now, both experts and the public will have to rely on a mix of new and older data to see where the flu is spreading most rapidly.
As of January 18, Influenza A has been found to be "very high" in wastewater samples from:
- Arizona
- Connecticut
- Florida
- Georgia
- Hawaii
- Massachusetts
- Minnesota
- Mississippi
- Missouri
- Nebraska
- North Carolina
- Oregon
- Pennsylvania
- South Carolina
- South Dakota
- Utah
- Washington
- Wisconsin
Influenza A has been found to be "high" in wastewater samples from:
- Alabama
- Alaska
- California
- Colorado
- Illinois
- Kentucky
- Louisiana
- Maryland
- Michigan
- New Jersey
- Ohio
- Rhode Island
- Tennessee
- Texas
- Vermont
- Virginia
- Wyoming
The CDC notes: "Wastewater data cannot determine the source of influenza A viruses. Detections could come from a human or from an animal (like a bird) or an animal product (like milk from an infected cow)."
What's more, this data doesn't "distinguish between influenza A subtypes (e.g. seasonal influenza A(H1N1) virus, seasonal influenza A(H3N2) virus and avian influenza A(H5) virus."
For more detailed info, the best the CDC can provide right now is its report from two weeks ago.
To keep yourself healthy, experts agree that it's still "worth it" to get vaccinated against influenza if you haven't yet. As of January 4, roughly 43% of U.S. adults and 43% of children had received an influenza vaccine, according to CDC data.
