More than 33,000 people with influenza were hospitalized during the week ending Dec. 27, with experts anticipating at least several more weeks of increases, according to the CDC’s latest FluView report, which was published Jan. 5.
“Just looking at the trajectory of the curve, it’s really a sharp increase that we’re seeing, and it’s not anywhere close to peaking or leveling off,” Daniel Kuritzkes, MD, an infectious diseases physician at Boston-based Mass General Brigham, told NBC News in a Dec. 30 report.
At least 33,301 people in the U.S. with laboratory-confirmed flu were admitted to hospitals in the week ending Dec. 27, up from 19,000 who were admitted the week prior, according to CDC data. The weekly hospitalization rate also increased week over week from 7.6 to 8.4 per 100,000 population.
ED visits, hospitalizations and outpatient visits related to the flu have all jumped in recent weeks, with experts anticipating the season to peak later this month or in early February. If flu activity peaks sometime in January, it would represent an earlier peak than in recent seasons, driven by the unusually early rise in cases this year. During the 2024-25 season — which was the most severe since 2010 — flu activity peaked in early February.
“I don’t remember seeing flu cases this early and in this many numbers,” Jennifer Goebel, DO, an attending physician at South Shore University Hospital, part of New Hyde Park, N.Y.-based Northwell Health, told NBC News. The hospital began seeing a significant uptick in flu cases around Thanksgiving.
Four more flu season updates:
1. The CDC estimates there have been at least 11 million flu cases, 120,000 hospitalizations and 5,000 deaths so far this season, including nine pediatric flu deaths.
2. Most states reported “high” or “very high” levels of flu-like illness for the week ending Dec. 27. A handful of states — Montana, South Dakota and West Virginia — reported low or moderate levels of activity. In Nevada, there was insufficient data to report activity levels, according to the CDC.
3. H3N2 viruses are the most commonly reported types of influenza viruses so far this season, CDC data show. A mutated version of the strain, known as “sublade K,” is believed to be driving the current surge. The strain emerged last summer and was responsible for early and severe outbreaks in Canada, the U.K. and Japan. While there is no evidence that the strain causes more severe disease, it does include mutations that make it more difficult for the immune system to recognize, enabling it to spread more quickly.
This year’s flu shot isn’t a close match to the strain. However, experts emphasize that vaccination still plays a critical role in preventing severe illness.
4. Many hospitals and health systems are relying on tried-and-true strategies such as enacting masking rules and visitor restrictions to help reduce the spread and mitigate capacity strain. Phoenix-based Banner Health is requiring patients, visitors and staff to wear masks at all of its facilities due to the surge in flu cases, according to a Dec. 31 announcement from the health system.
Several hospitals and health systems in New York — where weekly flu cases hit a record high in late December — have also reinstated mask recommendations and tightened visitor rules in recent weeks.
