The early flu season in the United States has pushed hospitalizations to their highest level for mid-October since the 2010-11 season, according to the Centers for Disease Control and Prevention. The agency reported the finding in its FluView report for week 41, covering the week ending October 17, 2026, and released on October 23.
Seasonal influenza activity remains low across the country, the CDC said. At the same time, several measures of influenza activity have been rising since late August or early September, and early-season activity is higher than is usually seen at this time of year. The pattern points to a season that started earlier than usual, with the virus reaching hospitals before many people have had their annual vaccination.
Flu hospital rates by age group
The observed weekly hospitalization rate in week 41 was 1.1 per 100,000 people, unchanged from the previous week. After accounting for reporting delays, the CDC estimated the true week 41 rate at between 1.5 and 2.0 per 100,000 people. The agency said that range is the highest weekly rate for week 41 since the 2010-11 season. The cumulative hospitalization rate observed by week 41 was 2.1 per 100,000 people.
FluSurv-NET, the CDC network that tracks laboratory-confirmed influenza hospitalizations in selected counties in 14 states, counted 798 hospitalizations between October 4 and October 17. The network covers about 10 percent of the United States population, so its rates are estimates drawn from a sample rather than a count of every hospital admission in the country.
Older adults carried the highest observed hospitalization rate in the FluSurv-NET data. Adults aged 65 and older had a rate of 7.4 per 100,000 people, followed by adults aged 50 to 64 at 2.3 per 100,000 and children aged 0 to 4 at 1.7 per 100,000. Adults aged 18 to 49 had a rate of 0.6 per 100,000, and children aged 5 to 17 had a rate of 0.5 per 100,000.
The CDC also reported age-adjusted rates by race and ethnicity. Non-Hispanic Black people had the highest rate at 3.2 per 100,000, followed by Asian and Pacific Islander people at 2.6, Hispanic people at 1.8, non-Hispanic White people at 1.7, and American Indian and Alaska Native people at 1.2. The CDC said FluSurv-NET data are preliminary and are updated each week as more reports arrive.
Among the hospital cases tracked by FluSurv-NET, 777 of 798 hospitalizations, or 97.4 percent, were linked to influenza A, and 20, or 2.5 percent, were linked to influenza B. Of the hospital cases with influenza A subtype information, 112, or 98.2 percent, were A(H1N1)pdm09, and two, or 1.8 percent, were A(H3N2). The CDC said most of the H1N1 viruses characterized so far belong to the D.3.1.1 subclade, which is dividing into groups with different genetic changes.
Flu test positivity and the H1N1 strain
Clinical laboratories tested 51,490 respiratory specimens in week 41 and found 2,918 positive for influenza, or 5.7 percent. That was up from 5.0 percent the previous week and 3.9 percent the week before that. Influenza A accounted for 97.9 percent of the positive clinical laboratory results, and influenza B accounted for 2.1 percent.
Public health laboratories reported 323 influenza viruses in week 41, of which 318 were influenza A and five were influenza B. Of the 241 influenza A viruses that were subtyped, 239, or 99.2 percent, were A(H1N1)pdm09, two were A(H5), and none were A(H3N2). The H1N1 strain in circulation is the same subtype that caused the 2009 pandemic and has circulated as a seasonal virus since then.
Flu activity in clinics and emergency departments
Outpatient visits for flu-like illness and emergency department visits with a flu diagnosis have also been rising since late August or early September, the CDC said. In week 41, 0.9 percent of emergency department visits carried a flu diagnosis, stable from the previous week. Visits rose among children aged 4 and younger and among children aged 5 to 17, while holding steadier among adults.
Every flu season is different, the CDC said, and some begin earlier than usual while others begin later. An early start does not by itself show how severe a season will become, and the agency will update its figures each week as more hospital, laboratory and clinic reports arrive.
Annual seasonal flu vaccination is recommended for people aged 6 months and older, the CDC said. For most people, vaccination should ideally be offered during September or October. The agency also said prescription flu antiviral drugs should be started as early as possible and are especially important for patients at higher risk of complications.