US records first child flu death as 'super' virus overwhelms cities
First pediatric fatality of the season reported as a new H3N2 subclade drives spikes across dozens of states; health officials urge vaccination and masking where appropriate.
The U.S. Centers for Disease Control and Prevention said in its weekly update for the week ending Dec. 11 that the country has recorded its first pediatric death of the 2025-2026 influenza season. The agency did not release details about the child.
Colorado health officials later confirmed the state's first influenza-associated death of a child for this season. The child was elementary school-aged and lived in Denver and died last week. It was not known whether this death is the same child referenced by the CDC. Officials said the death was associated with the influenza A strain. Colorado reported a 43% rise in flu-related hospitalizations in the last week of November, and CDC figures dated Dec. 6 showed high influenza activity in the state. Nationwide, influenza activity remains elevated in several large urban areas, with New York City reporting very high transmission and neighboring states also showing high levels of activity.
The current surge appears to be driven by a new H3N2 subclade known as subclade K, now detected in more than three dozen states. The CDC reported that about 89% of influenza A(H3N2) samples tested since September belonged to subclade K. It was not specified whether the Colorado child’s death was caused by this subclade. Health officials emphasized that the rise in cases is being observed across multiple regions as clinicians report increased hospitalizations and strain on health systems across the country.
On the national level, the indicators remain concerning. In the week of Dec. 6, 8.1% of flu tests were positive, up from 7.1% the week before. The rate of outpatient respiratory illness also rose, from 2.9% to 3.2%. Roughly 3 million people have contracted influenza so far this season, and about 1,200 deaths have been attributed to the illness, with around 30,000 people hospitalized. By this point last season, 268 pediatric flu-associated deaths had been reported. The latest data show an influenza hospitalization rate of 6.9 per 100,000 people nationwide, up from 4.3 per 100,000 the prior week. At this time last year, 5.1% of tests were positive and the hospitalization rate was about 3.1 per 100,000.
The seasonal pattern for influenza typically peaks between December and February, following the winter holidays. New York City’s acting health commissioner, Dr. Michelle Morse, described the city’s cases as “skyrocketing,” and urged residents to obtain the annual flu shot and to wear a mask if symptoms develop. In response to the surge, some hospitals and health systems have reinstated masking guidelines for patients, visitors and staff.
In New Jersey, Hackensack Meridian Health and RWJ Barnabas Health have reimposed masking protocols for patients, visitors and health-care workers. Detroit Medical Center also limited visitor access to protect patients and staff from the spread of illness. In other parts of the country, local authorities have reported additional measures as flu activity climbs. Private and public schools have responded as well: Villa Duchesne Catholic School in St. Louis, Missouri, and the Moulton-Udell school district in Iowa canceled classes or closed for several days due to high flu rates.
The classic flu symptoms remain typical and can come on suddenly, including fever, fatigue, chills, sore throat, headache, cough, body aches, congestion and a runny nose. Public health officials stress that vaccination remains the best protection against influenza, even as the current season’s dominant strain – a newer H3N2 variant – continues to circulate. Vaccine effectiveness varies by season and individual factors, but health experts generally advise vaccination as soon as possible.
The precise trajectory of this season’s flu outbreak remains uncertain as health departments continue to monitor the spread of subclade K and other circulating strains. Officials emphasize that people should seek care for flu-like symptoms promptly, especially if they are in high-risk groups such as young children, the elderly, pregnant individuals, or people with chronic health conditions. Continuous updates from the CDC and state health departments are expected as the season progresses and more data become available.