Flu virus tracker: Latest update shows high influenza activity across most states. Watch out for these symptoms

As today is the first Monday of 2026, Americans across the country are settling back into their everyday routines after the busy holiday season.

But many are also recovering from the flu—or still suffering from it.

Flu illnesses are surging across the country. According to the most recent data from the Centers for Disease Control and Prevention (CDC), positive influenza test results reached the highest levels of the season for the week ending December 27, 2025.

The CDC publishes a weekly influenza surveillance report that details positive case counts, illness activity levels by state, and breakdowns of flu types.  

Due to the winter holidays, the CDC’s latest weekly report was delayed. But the agency published its findings today, January 5, 2026. 

The report shows that 32.9% of samples tested positive for influenza. Positive influenza test results have continued to trend upwards in recent weeks. 

Influenza A H3N2 ‘Super Flu’ cases are surging nationwide 

Fast Company previously wrote about the worsening spread of the so-called super flu. The most common influenza strain this season is the subclade K, which is a mutated version of H3N2, a subtype of the influenza A virus.

According to CDC data, for the week ending December 27, a total of 994 influenza viruses were reported by public health laboratories. Of those, 971 were influenza A and 23 were influenza B. Of the 600 influenza A viruses that were subtyped, 91.2% were influenza A H3N2.

For the same week, 33,301 patients were admitted to hospitals with influenza. 

Meanwhile, two influenza-related pediatric deaths were reported. One death occurred the week ending December 20 and one death occurred the week ending December 27. A total of nine influenza-related pediatric deaths have been reported this season. 

For the week ending December 27, activity levels were considered very high in more than half of the U.S. states. Activity levels were also very high in Puerto Rico.

The states with the highest flu activity include:

• Alabama
• Alaska
• Arkansas
• Colorado
• Connecticut
• Florida
• Georgia
• Idaho
• Indiana
• Kansas
• Kentucky
• Louisiana
• Maine
• Massachusetts
• Michigan
• Minnesota
• Ohio
• Nebraska
• New Hampshire
• New Jersey
• New York
• North Carolina
• North Dakota
• Rhode Island
• Tennessee
• Texas
• Vermont
• Virginia

The CDC expects activity to continue for several weeks. 

What are the symptoms of the flu? 

Flu symptoms can vary from mild to severe. According to the CDC, these are the most common symptoms to be aware of: 

• Fever
• Feeling feverish/having chills
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headaches
• Fatigue (tiredness) 
• Possible vomiting or diarrhea

It’s worth noting that not everyone with the flu gets a fever.

If you’re experiencing flu-like symptoms, the CDC recommends limiting contact with others. 

Total flu cases reach 11 million nationwide 

The CDC estimates that at least 11 million flu illnesses have occurred so far this season. The agency estimates that there have been 120,000 hospitalizations and 5,000 deaths from the flu. 

The CDC recommends that everyone 6 months of age and older who has not yet been vaccinated this season get an annual influenza vaccine.

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