> At a Glance
> – Flu activity at “high” or “very high” in 32 states, up from 17 the week before.
> – Hospitalizations rose to 19,053, nearly double the prior week.
> – 7.5 million illnesses, 3,100 deaths, and 5 pediatric deaths this season.
> – Why it matters: Hospitals are stretched thin, especially for infants and young children, and the season may not peak until late January or February.
A surge in influenza cases is sweeping the United States, with the Centers for Disease Control and Prevention (CDC) reporting that flu activity has climbed to “high” or “very high” levels in 32 states as of the week ending Dec. 20. Hospitalizations have nearly doubled, reaching 19,053 this week, while 3,100 people have already died from the virus since the season began in October.
Current Flu Landscape
The CDC’s latest data shows a sharp uptick in flu activity across the country. 32 states now report “high” or “very high” levels, a jump from 17 the previous week.
| Metric | Week ending Dec. 20 | Week before |
|---|---|---|
| Flu activity states | 32 | 17 |
| Hospitalizations | 19,053 | 9,944 |
| Pediatric deaths | 5 | 2 |
The surge is most pronounced in the South and West, where new states-California, Nevada, Missouri, Arkansas, Alabama, and Florida-have entered the high-activity bracket. States already in the “very high” category, such as New York, New Jersey, South Carolina, Louisiana, and Colorado, have moved to the upper end of the range.
Expert Voices
**Dr. Daniel Kuritzkes, a senior infectious disease physician at Mass General Brigham, warned that the curve is still climbing.
Dr. Daniel Kuritzkes stated:
> “Just looking at the trajectory of the curve, it’s really a pretty sharp increase that we’re seeing, and it’s not anywhere close to peaking or leveling off.”
Dr. Jennifer Goebel, attending physician at South Shore University Hospital, noted the early and heavy influx of cases.
Dr. Jennifer Goebel said:
> “I don’t remember seeing flu cases this early and in this many numbers,”
> “It seems worse. Just a tremendous amount of volume.”
Dr. Donald Yealy, chief medical officer of the UPMC health system, described the pattern of admissions.
Dr. Donald Yealy said:
> “The biggest set of those are people with suspected influenza,”
> “And of those that we have adequate testing, it’s disproportionately influenza A.”
Dr. Lauren Siewny, medical director of Duke University Hospital Emergency Department, emphasized the strain on resources.
Dr. Lauren Siewny added:
> “We have built-in plans for these surges, and we prioritize the sickest patients first.”
Who Is Hardest Hit?
Infants and children under 5 are the most affected, with school-aged children and young adults also showing increased hospital visits. Older adults and those with chronic conditions face higher hospitalization risk.
- Infants & young children: most severe cases
- School-aged children & young adults: rising admissions
- Older adults & chronic disease patients: higher risk of severe outcomes
- Bed capacity: strained by overlapping COVID-19 and RSV cases
The New Variant
The dominant strain is Influenza A, specifically the fast-spreading, mutated H3N2 subclade K. This variant, sometimes called “super flu,” emerged in summer and carries changes to a key surface protein, making it harder for the immune system to recognize.
Dr. Wenqing Zhang of the World Health Organization noted:
> “Although the genetic shift makes a notable evolution in the virus,”
He added that current data do not suggest increased severity from the new strain.
Symptoms and Vaccine
Symptoms mirror previous seasons but can be more severe, especially in unvaccinated individuals and those with underlying conditions.
- Typical symptoms: high fever, shaking, chills, cough, shortness of breath, muscle aches
- Additional symptoms: headaches, fatigue, nausea, vomiting, diarrhea
- Severe complications: pneumonia, muscle breakdown, seizures
Dr. Molly Fleece explained that the vaccine still offers strong protection against severe illness.
Dr. Molly Fleece said:
> “Symptoms start acutely,”
> “People have higher fever, shaking, chills, cough, shortness of breath and muscle aches.”
> “Symptoms can be more severe, especially if a person is unvaccinated.”
> “Older adults and those with underlying medical conditions have also reported more serious complications, including pneumonia, muscle breakdown and seizures.”
> “That’s because the subclade mutated and spread after the vaccines were already selected for the year.”
> “But that doesn’t mean the vaccine is still very effective at preventing severe illness, hospitalization and death.”
Dr. Donald Yealy encouraged vaccination:
Dr. Donald Yealy stated:
> “The shot essentially arms your body with the appropriate response before you get infected.”
> “This year’s seasonal vaccine can help provide protection.”
Other Winter Viruses
COVID-19 infections are slowly rising nationwide, with higher levels in the South, Northeast, and Midwest. Norovirus remains high, and RSV is gaining traction, especially in the South. Co-infection can worsen illness.
- COVID-19: increasing, especially in certain regions
- Norovirus: still high and rising
- RSV: emerging, particularly in the South
- Co-infection: can amplify severity
Dr. Donald Yealy warned:
> “Having one virus doesn’t actually shun another one off.”
> “The bigger issue is having one of the respiratory viruses and it worsening a second condition.”
Key Takeaways
- Flu activity has surged to “high” or “very high” in 32 states, with hospitalizations nearly doubling.
- The mutated H3N2 subclade K is driving the spike, but the vaccine remains effective against severe outcomes.
- Infants, young children, and older adults with chronic conditions are the most vulnerable; vaccination is still the best defense.
The season’s peak may arrive only in late January or February, but hospitals are already stretched. Staying up-to-date on flu activity and getting vaccinated can help protect you and your loved ones from this relentless virus.
