The United States is in the midst of a late-season flu surge, data from the Centers for Disease Control and Prevention shows, with nearly 1 in 10 positive tests reported at the mid-April peak. .
But even with that uptick, an NBC News analysis of 7 years of CDC data shows this year’s flu season is still well below pre-pandemic levels.
“We’re at the last moment,” said Dr. Carrie Horn, medical director of National Jewish Health in Denver. “But they are not high enough to say there is a flu epidemic.”
It will be the first time since 1982 that such an increase has occurred so late in the typical flu season, said Lynnette Brammer, head of the CDC’s domestic influenza surveillance team.
“We’re not used to thinking about the flu in May, but it’s definitely still there,” Brammer said, adding that rates may go higher this season.
While this season has had far fewer cases than previous seasons, the late-season spike has brought positivity rates closer to where they would be at the end of a typical flu season.
So far this season, the CDC reported, there have been at least 5.7 million cases of the flu and some 59,000 hospitalizations. Some 3,600 people have died, including 24 children.
Respiratory illnesses are on the rise in New Mexico and Colorado in particular, according to the latest influenza data from the CDC.
Doctors there say patients are coming in with a fever, cough, body aches, which could indicate the flu, covid-19 or other respiratory viruses.
“Almost every day, I see at least one person with a case of something that we need to figure out,” said Dr. Melissa Martinez, a professor of internal medicine at New Mexico University of Health Sciences.
But in fact it is the flu that is proving to be behind several of today’s respiratory illnesses, Martinez said. In recent weeks, the proportion of positive tests for Covid within the UNM Health Sciences system has hovered around 4 percent, she said, while the proportion of positive tests for the flu is as high as 17 percent. .
The timing of flu cases is unusual, Martinez said. “Seeing an increase in influenza this late in the season is really strange.”
The flu is usually spread through respiratory droplets when a person sneezes, coughs, or even talks. The uptick coincided with Covid-19 masking largely down to a minimum across the country.
Despite the increases in flu cases, Martinez said, the total number of flu cases is low compared to previous seasons.
“It’s a drop in the bucket compared to what we’ve seen in other years,” he said.
While the current season’s test positivity rate has yet to exceed 10 percent, previous seasons in the recent past have peaked at more than 30 percent.
The dominant strain this year has been H3N2, which experts say tends to be more virulent and often causes more severe illness.
Because cases are peaking so late in the season, there’s still time to get a flu shot, Brammer said, even though the vaccine isn’t an ideal match for the current strain circulating.
Testing to determine the cause of a respiratory illness, whether it’s the flu or Covid, is critical, Martinez said. There are specific antiviral treatments for both viruses, but they work best when given early in the disease.
“We really want to start on the right treatment as soon as possible,” he said.
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