California is reporting what the Centers for Disease Control and Prevention described as "very high" flu levels as cases surge nationwide.
A map released by the CDC shows California and 10 other states in the top "very high" category. Nationwide, flu hospital admissions almost doubled last week.
Visits to doctors' offices, urgent care and emergency rooms are the highest they have been in the last decade.
In Los Angeles County, flu rates have reached 25% -- a level not seen at this time of year in the past four years, many of them are children.
"We are seeing a tremendous number of children with Influenza A," Dr. Anthony Cardillo, an emergency room specialist and CEO of Mend Urgent Care, said in an interview with ABC7. "That's because they're back in school, they're in athletics, they're doing different things, a lot of transmission is happening.
"The only difference this year is this flu virus is very, very strong. It's had time to mutate. And that's what we're seeing now."
The annual winter flu season usually doesn't get going until December or January, but this one began early and has been complicated by the simultaneous spread of other viruses.
The measure of traffic in doctor's offices is based on reports of symptoms like coughs and sore throats, not on lab-confirmed diagnoses. So it may include other respiratory illnesses.
That makes it hard to compare to flu seasons from before the COVID-19 pandemic. Other years also didn't have this year's unusually strong wave of RSV, or respiratory syncytial virus, a common cause of cold-like symptoms that can be serious for infants and the elderly.
Flu shots are recommended for nearly all Americans who are at least 6 months old or older.
The Associated Press contributed to this report.
¿Quieres leer este artículo en español? Haz clic aquí