Early flu season in U.S. may be peaking early, too

This year’s abnormally early flu season is showing signs it may be peaking in parts of the country, data the Centers for Disease Control and Prevention released on Friday suggested.

The percentage of outpatient visits to health care providers that were for respiratory illnesses declined for a second week in a row, CDC’s weekly influenza report, FluView, showed. And the number of people hospitalized for influenza declined in the week ending Dec. 10, as compared to the previous week.

“Activity is still really high. But it does look like things might be starting to decline in some areas of the country,” Lynnette Brammer, team lead for domestic surveillance in the CDC’s influenza division, told STAT in an interview.

Decreases in flu activity have been seen in the southeast and the southwest regions, in some of the mid-Atlantic states, and several states across the north-central part of the country. Activity remains very high in many New England states, parts of the Pacific northwest, and some of the south-central states.

The CDC reported nine more pediatric flu deaths, which occurred in November and December. (There is typically a lag in the reporting of pediatric flu deaths.) They bring to 30 the number of children who have died from flu so far this season. “We never like to see that number go up,” Brammer said, though she noted the total is still lower than what was typically recorded in flu seasons prior to the Covid-19 pandemic. Pre-Covid, somewhere between 100 and 200 pediatric flu deaths were recorded most seasons.

This is the first really active flu season the United States has seen since the Covid pandemic shunted influenza and other respiratory viruses to the side. Its surprisingly early start, in the first week of October, and the sharp spike in activity that followed has been unsettling, and has led to some predictions that the country is facing a prolonged or a severe flu season as a consequence.

But Brammer said to date there is no evidence that this season is triggering an unusual percentage of severe infections. There has just been a lot of flu, primarily in children and young adults. She noted, though, that the proportion of cases in people 65 and older has risen in the past few weeks. Flu-related deaths mainly occur among the elderly.

“Not that there is an average flu season, but it’s within the bounds of what we saw during flu seasons prior to the pandemic,” Brammer said. “It doesn’t look particularly severe.”

The CDC estimates that so far this year about 15 million people have been ill with the flu and 150,000 of them have needed to be hospitalized. It also estimates there have been roughly 9,300 flu deaths. In the pre-Covid era, CDC estimated that between 12,000 and 52,000 Americans died of flu per year.

The holidays are fast approaching; with them come lots of intergenerational mixing, which provides plenty of opportunities for children to pass their respiratory infections to older members of their families. Could flu transmission start to spike again?

Brammer said she wasn’t sure. Sometimes over the winter holidays, case numbers actually decline, because children aren’t congregating and swapping flu and other viral infections, she said, adding that transmission can pick up again once kids are back in school.

“Flu’s so unpredictable. I don’t know,” Brammer said. “It doesn’t feel like we’ve gotten back into our routine. So I don’t know if things are going to behave the way they used to behave or not. I think we’re just really going to have to wait and see.”

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