A deadly quad-demic is taking shape in the US as the months get colder and people gather indoors, threatening to overwhelm hospitals, disrupt children’s education and pose a deadly risk to vulnerable seniors.
Winter surges of Covid, respiratory syncytial virus (RSV), norovirus, commonly called the stomach flu, and influenza have become regular occurrences since the pandemic has waned. But this year, the US is contending with a dangerous superflu.
Cases of influenza are climbing in more than three dozen states. They are on track to overshadow last year’s particularly severe flu season, during which there were 560,000 hospitalizations and approximately 38,000 deaths between September last year and August.
The new influenza strain, H3N2 subclade K, is ripping through the UK, especially among seniors and people with compromised immune systems. This dominant strain does not match this year’s flu shot and has shown signs of causing more severe illness.
The CDC has reported that between 1.9 million and 3.3 million Americans have had the flu since October 1 and 19,000 to 38,000 have been hospitalized. The surge has led to a reinstatement of mask mandates across several states for everyone entering a hospital.
Several states have been hit particularly hard. Flu activity in Massachusetts is accelerating sharply, signaling an early and potentially deadly season. In just over two weeks, hospitalizations linked to flu more than doubled, reaching 0.4 percent of all admissions by mid-November.
The surge has been reflected in lab data, with confirmed cases jumping from 251 to 450 in a single week.
And in Iowa, the Moulton-Udell school district took the drastic step of canceling classes for two days due to an ‘extremely high percentage’ of illness among students and staff. The district has also called off athletic events. Nearly 30 percent of students and staff are sick.
Iowa’s statewide burden of flu and COVID has been deemed low by the Iowa Department of Health and Human Services, though signs point to an imminent increase in case rates as the season progresses.
The rate of lab-confirmed flu tests in the state has been creeping up, mirroring the same track as last year’s gradual then abrupt rise.
About 3.5 percent of COVID PCR tests collected in Iowa came back positive in the second-to-last week of November, a 0.5 percent increase from the previous week.
At the same time, central Iowa’s Polk County Public Health’s communicable disease team has been seeing a rise in calls with questions regarding ‘stomach illnesses that are consistent with norovirus,’ according to Addie Olson, the department’s communications officer.
Public health officials at the CDC have said that while this year’s flu season has begun earlier than last year, it is still projected to follow a similar pattern and overall severity as last year.
The CDC’s models suggest the circulating viruses like H3N2 may behave similarly in terms of transmissibility and severity as last year’s strains, leading to a comparable total number of estimated illnesses and hospitalizations over the full season.
An earlier start does not necessarily mean a higher peak or worse outcome. It typically means the season will be longer and more drawn out.
No one has ever been exposed to this strain of influenza before, leaving immune systems vulnerable to potentially severe illness requiring hospitalization. It also arrived too late to include in this year’s shots.
Oregon public health experts have sounded an early alarm about the future burden this confluence of viruses will have on hospitals, with special emphasis on the never-before-seen flu strain.
They urged people to take preventive measures, including getting a flu shot and wearing a mask in public, to keep hospital beds free for non-flu patients as well.
Shereef Elnahal, president of Oregon Health and Science University, said at a press conference last month: ‘The CDC is warning that this flu season could be as bad as last year’s flu season, which was the worst on record on hospitalizations and severe disease.’
Dr Dawn Nolt, an infectious disease expert at OHSU, said: ‘We don’t have that many beds. So one bed that’s needed to treat a child with a respiratory illness is one less bed for the child who has to recover from surgery from appendicitis, who needs treatment for a bleeding disorder, or for the child who decides to take up skateboarding in the middle of winter and has a fracture.’
Colorado’s flu season has also gotten an earlier start than last year’s, with state epidemiologist Dr Rachel Herlihy reporting notably higher rates of hospitalizations, emergency room visits and positive tests.
Herlihy emphasized the urgency for those who have not yet received their flu shot to do so immediately, particularly noting that it takes a full two weeks after vaccination to develop complete immunity.
Dr Herlihy noted that, for now, activity from COVID and RSV remains low. She explained that the staggered peaks of respiratory viruses were beneficial for the healthcare system, as they prevent a simultaneous surge of patients from multiple illnesses.
Based on the latest CDC data, the spread of influenza is increasing nationally. In clinical labs, 7.1 percent of tests are now positive for the virus, a rising trend.
Four jurisdictions are currently reporting the highest level of flu activity: Louisiana and New York City at Level 10, followed by Colorado and New York at Level 9. A broader cluster of states, including Idaho and New Jersey, are experiencing ‘Moderate’ activity
This outlook serves as a baseline for what could occur during the 2025-2026 season. The CDC expects the upcoming fall and winter respiratory disease season will likely have a similar combined number of peak hospitalizations due to Covid, flu and RSV compared to last season
Outpatient visits for respiratory illness have risen to 2.9 percent of all healthcare visits, a level that remains below the national baseline, according to the health agency. This indicates the overall strain from flu and other viruses has not yet reached an epidemic threshold.
Four jurisdictions are currently reporting the highest level of flu activity: Louisiana and New York City, both at the maximum Level 10 followed by Colorado and New York, each at Level 9.
A broader cluster of states, including Idaho and New Jersey, is experiencing ‘Moderate’ activity.
The vast majority of the country remains at ‘Low’ levels for now, indicating that while significant regional hotspots exist, widespread national flu activity has not yet taken hold.
Hospitals across the US, including major networks in New Jersey and wealthy Sonoma County in California, are reinstating mask mandates for staff, patients and visitors amid the winter respiratory virus surge.
Dr Karen Smith, Sonoma County’s interim health officer, said: ‘The risk to vulnerable patients of COVID, flu and other respiratory viruses in health care remains significant.
‘So, it continues to be important for face masks to be used in patient care areas when the seasonal risk of exposure to one or more viruses is high.’
Sonoma’s mask mandate is based on a county masking policy first established in 2017 and applies to staff and visitors at nursing homes, long-term care facilities, rehab centers, infusion clinics and dialysis centers.
Based on forecast models, the potential peak of weekly Covid hospitalizations this season could surpass last season’s levels, especially if a new variant emerges in the fall that demonstrates a moderate ability to evade existing immunity
RWJ Barnabas Health, which operates 14 hospitals, followed Sonoma’s lead and reinstated last year’s mandate, requiring masks for direct-care employees, patients leaving their rooms and all visitors in patient areas.
The move follows a recent increase in hospitalizations linked to respiratory illnesses, particularly among adults over 65 and young children. The leading culprit is the H3N2 subtype of Influenza A.
Signs from the UK point to potentially untenable surges in hospitalizations due to the new flu variant.
According to the UK Health Security Agency, doctors are reporting a rise in cases, reflected in a hospitalization rate of approximately 7.79 per 100,000 people.
The earlier-than-usual flu season has yet to reach its peak, with current activity classified as ‘medium’.
And in Japan, the news outlet Nippon TV reported that flu cases in Tokyo have surged to nearly six times the level seen at the same point last year, citing data from the Japanese Ministry of Health, Labor and Welfare.
The outbreak has caused significant disruption across the country, leading to the partial or full closure of more than 2,300 daycares and schools.
Anti-vaccine graffiti is seen on the wall of a shop amid the outbreak of the coronavirus disease (COVID-19) in Belfast, Northern Ireland January 1, 2021. REUTERS/Phil Noble
Flu is an unpredictable virus that mutates quickly, so scientists say it remains to be seen whether H3N2 will remain the dominant strain through the season, nor is it clear that the strain causes more severe illness than previous strains, leading public health officials to urge people to vaccinate.
Written by Cassidy Morrison for The Daily Mail ~ December 9, 2025