Flu activity is rising sharply across much of the US, with health officials warning that cases are increasing earlier than usual.
The Centers for Disease Control and Prevention (CDC) said Friday that flu levels were “higher than typically observed at this time of year” and continued to climb in many parts of the country.
In its latest update, the agency estimated that more than 1.7 million people had contracted influenza by the week ending October 31, the most recent period available. That figure was 70 percent higher than the estimate from the previous week.
More than 25,000 people were estimated to have been hospitalized with flu, a 56 percent weekly increase, while approximately 1,400 people had died after developing a flu infection—up 55 percent from the prior week.
By comparison, flu activity was so low at this point last year that health officials had not yet released estimates for cases, hospitalizations or deaths. The first estimate came for the week ending November 15, when more than 650,000 illnesses were believed to have occurred. Cases did not reach this week’s level until the end of that month.
Flu activity increased across 26 states during the latest reporting week, with affected states spanning the South, West, Midwest and Northeast.
Louisiana and South Carolina are now reporting high flu activity. Five other states—Washington, California, Texas, Florida and Oregon—are reporting moderate levels.
The previous week, only three states had reported moderate or high flu activity.
Flu typically begins circulating in October, reaches its peak between December and February, and gradually declines through May.
This year, however, CDC data showed that activity had already started rising during the week ending August 8 and has continued to increase ever since.
Flu activity also usually emerges first in the South before spreading across the rest of the country.
Official data instead showed the initial increase occurring on the West Coast this year, an unusual pattern noted by doctors.
The early nationwide increase has been associated with H1N1, the influenza strain responsible for the 2009 flu pandemic, which sickened 60 million people and resulted in more than 240,000 hospitalizations.
Experts say H1N1 is responsible for most cases across the country and has developed a new mutation known as G155E. The change could help the virus evade existing immunity and cause infection, although there is no evidence that it produces more severe illness.
CDC health officials have stressed that an earlier flu season does not necessarily mean the season will be more severe than those in previous years.
In its latest update, published today, the CDC said the weekly flu hospitalization rate had risen to 2.5 per 100,000 people, compared with 1.8 per 100,000 the week before.
The Centers for Disease Control and Prevention warned Friday that flu cases were “higher than typically observed at this time of year”
The states reporting increased flu activity were Washington, Oregon, California, Michigan, Maine, Indiana, Oklahoma, Texas, Colorado, Arkansas, Louisiana, Tennessee, Mississippi, Alabama, West Virginia, Kentucky, Ohio, Virginia, Georgia, New York, South Carolina, Florida, New Hampshire, New Jersey, Massachusetts and Rhode Island.
South Carolina recorded one of the largest increases, moving from moderate to high flu activity this week.
Texas, Florida, California, Washington and Oregon were among the states where rising activity pushed levels from low to moderate.
YOU MAY ALSO READ: District Attorney and NBA Player’s Ex-Wife Dies by Suicide at Home
Two flu-associated deaths among children have been reported, one more than the previous week.
Experts are urging Americans to receive their flu vaccine as soon as possible.
Estimates indicate that vaccination reduces the risk of infection by 34 percent and hospitalization by 30 percent, although protection varies from year to year. Doctors say the vaccine takes at least two weeks to become effective.
The vaccine is recommended for everyone aged six months and older and is generally covered by health insurance. Adults over 65, young children and people with underlying health conditions face a greater risk of severe flu complications.
Influenza, commonly called the flu, is one of the most widespread and contagious respiratory infections, affecting about 8 percent of the US population each year.
Symptoms can include fever, coughing, a sore throat, a blocked or runny nose, headaches and fatigue. In some cases, the infection can cause serious complications such as pneumonia and influenza-associated encephalopathy, a severe form of brain dysfunction.
Three types of influenza viruses can cause illness: types A, B and C.
The strain responsible for the 2009 swine flu pandemic has been linked to an early rise in US flu cases this year
Influenza A can infect both humans and animals, while influenza B is generally found only in people and is usually linked to less severe illness.
Influenza C is far less common than types A and B and typically causes mild illness in humans.
Although most people recover within about a week, some develop complications such as pneumonia. The condition can be life-threatening and may require medical care.
Last year brought an especially severe flu season, as a surge dubbed “super flu” was driven by subclade K, a heavily mutated version of the influenza A (H3N2) virus that triggered a rapid and serious rise in cases nationwide.
Because the strain was new to people’s immune systems, many were particularly vulnerable to severe illness requiring hospitalization.
Symptoms were similar to those caused by other flu strains, but experts said the “super flu” variant was producing more serious illness, particularly among children. Reported signs included fevers lasting a week and coughing that caused breathing difficulties.
The 2025-2026 respiratory season recorded at least 32 million flu cases, according to the CDC, along with about 390,000 hospitalizations and 24,000 deaths.
H1N1, the dominant strain this year, was last the leading strain during the 2023-2024 flu season.
During the 2009 swine flu pandemic, H1N1 was linked to 60 million illnesses, 240,000 hospitalizations and 12,400 deaths.
To reduce the risk of infection, health officials recommend washing hands regularly and avoiding close contact with people experiencing flu-like symptoms.
Treatment may include rest, plenty of fluids and over-the-counter medicines. In more serious cases, doctors may prescribe antiviral drugs such as Tamiflu.
