Reports of the flu and other respiratory illnesses are higher than would normally be seen in the United States at this time of year, the Centers for Disease Control and Prevention said Thursday.
“We’ve noticed that flu activity is starting to pick up in much of the country,” especially in the southeastern and south central US, CDC Director Dr. Rochelle Walensky told NBC News.
“Not everyone got a flu shot last year, and a lot of people didn’t get the flu. That sets us up for a potentially serious flu season.”
Typical flu seasons peak in December and usually peak in February.
Walensky’s warning comes ahead of a CDC report on the spread of the flu that is expected on Friday. The agency is expected to say that flu and similar viral illnesses are notably high in Arkansas, California, Georgia, Louisiana and Texas.
In fact, said Dr. James Cutrell, an infectious disease expert at UT Southwestern Medical Center in Dallas, “we’re definitely seeing a pretty steep rise” in both documented flu and influenza-like illnesses.” This includes both children as well as adults, Cutrell said.
Doctors are not required to report every positive test for influenza to public health officials, so the CDC and others monitor likely influenza activity by looking at “influenza-like illnesses.” Those are defined as having a fever of at least 100 degrees and a cough and/or sore throat without any other known cause.
On Wednesday, a San Diego school district said there were “hundreds” of absences at a local high school, likely due to a flu outbreak, NBC affiliate KNSD reported. Most of the children said they had a cough, sore throat, congestion and fever.
Tests for Covid have so far been negative, the station reported. Several students, however, have tested positive for the flu.
“Unfortunately, we anticipated that this would be a difficult flu season,” said Dr. Cameron Kaiser, deputy director of public health for the San Diego County Health and Human Services Agency, according to a KNSD report. “Along with covid-19, other respiratory viruses are also rapidly making a comeback.”
This includes respiratory syncytial virus, or RSV.
“Right now, we’re in a big RSV spike,” said Dr. Frank Esper, an infectious disease expert at the Cleveland Clinic. RSV often affects infants, but can also be problematic in adults with underlying lung problems, such as asthma and chronic obstructive pulmonary disease.
Esper said RSV cases are typically seen in December and January, but for the past two years, the typical RSV season has come earlier, during the summer and early fall. Rhinoviruses and enteroviruses are also circulating earlier than usual. This is because measures to slow the spread of Covid did not allow other viruses to spread as they have historically.
“Flu is on the rise, but it’s also all these other viruses that have gotten out of control,” Esper said. “This could be the new normal. We don’t know.”
There is no vaccine for RSV, however there is one for influenza. So far this year, Walensky said, “about 12 million flu shots have been administered in pharmacies and doctors’ offices.”
That’s slightly less than the number of doses given at this time last year, he said, acknowledging that vaccine fatigue could contribute to the lower rate so far.
It takes about two weeks after the flu shot to provide full protection. The CDC recommends that everyone 6 months of age and older get a yearly flu shot.
“We want people to be protected before they get influenza in their own communities,” Walensky said.
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Michael Almaguer contributed.