Experts have warned that this season’s new ‘super flu’ is showing signs of resurgence after finally slowing last month.
The latest data released by the CDC shows 18 percent of tests for influenza came back positive during the week of January 24, up slightly from 17.7 percent the previous week.
The rate of outpatient respiratory illnesses has also increased from 4.4 to 4.7 percent, the data shows, suggesting an uptick in illnesses.
The cases have largely been driven by H3N2 subclade K, nicknamed ‘super flu,’ which has been linked to longer lasting, more severe symptoms than previous variants. According to the CDC, of H3N2 samples collected since September, 90 percent have belonged to subclade K.
An additional eight children also died from the flu and its complications in the last week , the figures show, bringing the total number of pediatric influenza-related deaths to 52 for the season.
And despite consistent nationwide declines in viral activity, six states are reporting ‘very high’ levels of influenza viral activity: Missouri, Louisiana, Colorado, Texas, South Carolina and Oregon.
South Carolina is battling super flu alongside a historic measles outbreak, which has infected 847 people since October 2025, 20 of whom were fully vaccinated against the disease.
Infectious disease experts have warned that despite the holiday season, a main driver of winter respiratory illnesses, being over, super flu is still a threat, especially to vulnerable populations like children.
Health officials warn this year’s virus season is far from over amid as slight uptick in positive tests. The virus has prompted school closures and pandemic-era restrictions
Dr Caitlin Rivers, an epidemiologist and associate professor at Johns Hopkins Bloomberg School of Public Health, told CNN: ‘We are seeing a second peak, a second rebound from flu. It’s concentrated in school-age children.
‘Children and kids are always the first to register new trends. So I do think that the increase will hit adults as well, but for now, it’s really concentrated in kids.’
She also noted these trends are similar to last year’s flu season, when the virus climbed to a second peak in late February after an initial decrease.
Several schools across the country have had to close or move to remote learning due to high flu activity. Last week, Keota Community School District in Keota, Iowa, announced its elementary and junior/senior high schools would be closed for one day due to ‘a high volume of illness among students and staff.’
The district, in the 900-person town of Keota, did not specify which illnesses were involved and how many students and staff may have become sick. The district has around 300 students split between the elementary and junior/senior high school.
In December, Villa Duchesne Catholic School in St Louis, Missouri, shut down in and canceled classes for multiple days for emergency flu testing and investigation.
Iowa’s Moulton-Udell school district also canceled classes and sports after nearly 30 percent of students and staff fell ill around the same time. Officials labeled the two-day shutdown a necessary response to an ‘extremely high’ rate of sickness.
Ellie Ann Rudd, 4, of Utah died after she battled a case of the flu so severe that it caused her to have a stroke. She is pictured above
The above graph shows the hospitalization rates for the flu this season, which have been decreasing since late December 2025
Detroit Medical Center also restricted visitor access in December to protect patients and staff from the spreading virus. The updated guidelines limit guest numbers, visitors under 12 and anyone 13 and up who is currently sick.
The change came after masking requirements for hospital staff and visitors in New Jersey and New York hospitals were reinstated.
Despite a slight uptick in infections, the latest CDC data also shows decreases in hospitalizations and mortality.
The weekly hospitalization rate for the week of January 24 was 26.4 per 100,000 compared to 43.5 per 100,000 the week prior. A total of 15,080 people were hospitalized with the flu during the week of January 24 compared to 17.963 the week before.
The mortality rate also decreased from 1.8 to 1.5 percent from January 17 to January 24.
An annual flu vaccine is the best method for preventing the illness and is between 30 and 75 percent effective depending on the variant. However, CDC figures show less than half of Americans have gotten the shot this season.
