Texas is battling a surge in influenza cases, with activity now at a “very high” level for the first time this season, according to data released by the Centers for Disease Control and Prevention. Emergency room visits due to the flu are climbing sharply, signaling a potentially difficult winter for public health officials and families alike.
A map shows the levels of influenza activity across the U.S. for the last week of December 2025.
What are the symptoms of the flu and how can I tell if it’s different from COVID-19? Understanding the differences between these respiratory illnesses is crucial for appropriate care and preventing spread.
Flu Surge in Texas: What You Need to Know
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The Lone Star State is experiencing a significant uptick in influenza cases, prompting health officials to urge preventative measures.
- Flu activity in Texas reached “very high” levels in the final week of December.
- Nearly 25,000 flu-related emergency room visits were recorded in Texas during that same week.
- Children ages 5 to 11 are disproportionately affected, accounting for over a quarter of ER visits.
- The dominant strain is influenza A (H3N2), and vaccination remains the best defense.
In the last week of December, Texas reported almost 25,000 emergency room visits related to the flu, according to the CDC. Children aged 5 to 11 are bearing the brunt of the illness, representing more than 25% of all flu-related emergency room visits statewide.
“It’s been really, really startling,” said Dr. Jeff Shilt, president of Texas Children’s Hospital in Austin. He noted the unusually high number of previously healthy children hospitalized with severe symptoms, across all age groups. “What’s most startling to us is the number and the severity.”
Health officials attribute the surge to influenza A, specifically a rapidly spreading H3N2 subtype. While vaccination is still recommended, doctors emphasize it offers important protection against severe illness.
Nationally, flu activity is also on the rise, but other respiratory viruses like COVID-19 and RSV remain at low levels in Texas and much of the country, the CDC reports.
Travis County is mirroring the statewide trend, with the CDC reporting a high level of flu-related emergency room visits. Doctors in Austin have observed that the most severe cases are occurring in unvaccinated individuals.
What is the H3N2 Subclade K Strain?
The vast majority of current cases are influenza A, including the H3N2 subtype. Determining the exact number of H3N2 cases is challenging, as most tests only identify influenza A or B. The CDC also analyzes a sample of positive tests, rather than all cases.
According to Jennifer Nuzza, DrPH, professor of epidemiology and director of the Pandemic Center at Brown University School of Public Health, the H3N2 virus is “quite common,” as stated in the Journal of the American Medical Association (JAMA). The journal identifies it as “a key cause of seasonal flu, alongside influenza A subtype H1N1 and influenza B viruses.”
H3N2 has recently gained attention due to its increasing mutations. The current version is known as subclade K. During the last week of December, 90% of the H3N2 cases that were subtyped by the CDC were subclade K.
While the flu shot has shown reduced effectiveness against this subtype, it still provides protection against severe illness.
COVID-19 vs. Flu: What are the Differences?
Currently, COVID-19 levels are low both nationally and in Texas. However, both COVID-19 and the flu share many similar symptoms, ranging from mild to severe.
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- High fever of 102 degrees or higher
- Body aches
- Sore throat
- Runny or stuffy nose
- Cough
- Chest congestion
- Headache
- Muscle aches
- Feeling very tired
- Sweating and chills
- Nausea
- Diarrhea
- Stomach pain
- Stomach issues are more common in children than adults
Diagnosis: Flu test either with the new over-the-counter test or in the doctor’s office
Treatments:Antivirals for people who are older than 65 or have a chronic illness, symptom management
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- Fever or chills
- Shortness of breath
- Sore throat
- Runny or stuffy nose
- Cough
- Headache
- Loss of taste or smell
- Muscle aches or body aches
- Fatigue
- Nausea or vomiting
- Diarrhea
- Nausea
- Stomach pain
- Stomach issues are more common in children than adults
Diagnosis:COVID-19 test, either the over-the-counter one or in the doctor’s office
Treatments:Antivirals, especially for people who are older than 65 or have a chronic illness, symptom management
How to Prevent the Spread
- Isolate the person into their own room if possible.
- Stay home until symptoms have passed, and you are fever-free for 24 hours without fever-reducing medication.
- Wash hands frequently, especially before eating.
- Wipe down surfaces.
- Wear a mask around the infected person, and have them wear a mask as well, to prevent the spread of flu, COVID-19, or any respiratory infection.
