There had been 1,614 cases of the flu as of Tuesday, according to the Springfield-Greene County Health Department influenza dashboard. More than a quarter of those were in kids age 5 to 14.
One reason for a spike just after the holidays is believed to be due to a strain of the flu that's being called "super flu." It's variant Influenza A, which is one of the common variants we see going around each year. The Influenza A strain is called subclade K and is being noted as a fast-spreading strain with a potential severity component.
This subclade K strain is dominant this winter due to its ability to spread quickly, potentially adding to the spike in flu cases in the U.S. and in Missouri. The Missouri Department of Health and Human Services noted that seasonal influenza activity was “very high,” with over 9,000 cases of both Influenza A and B recorded in the last week of December, likely fueled by holiday gatherings. There were 7,582 cases during the week of December 28 through January 3.
Given the name the "super flu," the subclade K strain is a typical strain of Influenza A, according to Anna Kremer, public information officer for the Springfield-Greene County Health Department. She said it’s hard to say if subclade K is the dominant strain of Influenza A in our area, but they’ve seen cases rise week by week in Springfield with Influenza A being the dominant variant.
“It does seem to be spreading more quickly, so that’s where the name ‘super flu’ came from,” she said.
According to the Wellcome Sanger Institute, subclade K could be causing a rise in cases because it has genetic mutations that cause infection easily.
This strain also isn’t a perfect match to the current flu vaccine – meaning subclade K might have an advantage against the vaccine. But, Kremer said, the CDC doesn’t yet have sufficient evidence that subclade K actually causes more severe illness than the other strains of Influenza A.
Although there is a slight genetic difference between the strain and the current flu vaccine, the Wellcome Sanger Institute said vaccinating still provides protection against severe disease.
Kremer added that getting vaccinated is key, especially with a new strain.
“Even though it's not an exact match for the super flu, it does still offer protection,” said Kremer.
Each year the Influenza A and B variants result in respiratory illnesses and some deaths. She said it's the same with the subclade K strain, but getting the vaccine for any of kind of influenza decreases the risk of severe illness or complications.
