Flu Season Arrives Early as Louisiana Leads Nation in Flu Activity and H1N1 Cases Climb Across the West Coast

Flu season is arriving earlier than usual across much of the U.S., with Louisiana reporting the highest flu activity in the nation. Doctors say a mutated H1N1 strain is driving many of the early infections.

Louisiana is the only state with a "high" flu activity rating from the Centers for Disease Control and Prevention. Most of the rest of the country is still reporting minimal or low levels. As of late October, Louisiana's flu test positivity rate was 10.9%, compared with a national average of 7.6%, according to CDC data cited by Axios. State health officials say about 4.3% of all outpatient visits in Louisiana now involve flu-like illness.

"The only thing predictable about a flu season is that it's unpredictable," said Dr. Fred Lopez, a professor of medicine at LSU Health New Orleans. "But there does seem to be early-season flu activity that's higher than usually seen at this time of year."

Lopez said the dominant subtype this season is H1N1. "There is a mutation that's been noted in this subtype, relative to last year," he said. He added that it is unclear whether the change is why cases are appearing earlier, or whether vaccine protection may be weaker against it.

He said Louisiana residents are especially vulnerable because of low flu vaccination rates and a large uninsured population.

Urgent care clinics in New Orleans are filling with flu patients. "And we feel it in the urgent care," said Dr. Hector Cabrera of LCMC Health. He said the 2026-27 season started earlier than usual, noting that cases typically begin rising in December.

South Carolina now ranks second in the nation for flu activity, according to the CDC. Doctors there say RSV and COVID-19 are also rising.

"All three respiratory viruses, not just flu, are kind of reaching for the sky right now," said Dr. Scott Curry, a hospital epidemiologist at the Medical University of South Carolina.

At Roper St. Francis Healthcare in Charleston, community test positivity has more than doubled in a month to about 12.5%. "Anything over 10% in the community means that this is a widespread illness, and it could get worse," said Dr. Robert Oliverio, a chief medical officer at the health system.

On the West Coast, where flu usually arrives later in the season, several states are already seeing moderate activity driven largely by H1N1, according to CDC data cited by NBC News. NBC also reported that the mutated version of one circulating strain may leave teenagers and young adults more vulnerable than in past seasons. North Texas is also seeing an earlier-than-usual start, The Dallas Morning News reported.

Health experts caution that an early start does not necessarily mean a more severe season, although it does give the virus more time to spread before the holidays, when travel and indoor gatherings increase.

Doctors say it is not too late to get vaccinated. The flu shot is updated every year to match the strains expected to circulate, and it reduces the risk of severe illness and hospitalization even when it does not prevent infection. The CDC recommends annual flu vaccination for everyone 6 months and older. It takes about two weeks after vaccination for protection to build.

Health officials also recommend frequent handwashing, staying home when sick and covering coughs and sneezes to slow the spread of respiratory viruses.