George Howell - (CNN) -- We've heard a lot in recent months about the spread of dangerous infections, such as Ebola. But doctors in the U.S. say there is a much higher risk for a far more common virus -- influenza.
In fact, this year's flu season is proving deadly for children. One of the most recent flu-related deaths is a three-year-old girl from Iowa. Her parents say she went from perfect health and no pre-existing conditions, to becoming severely dehydrated and in pain, and then rushed to a hospital in Des Moines, where she later died. This is just a few days after showing initial signs of the flu.
There was another tragic case, this time in Minnesota, where seven-year-old Ruby Hansen died Christmas eve.
Her mother believes Ruby might have survived had she not had a pre-existing medical condition. "The flu would have not did her in had she not had Drevey Syndrome," Debra Hansen said. "She had a seizure that was caused by the flu."
These latest deaths -- now, part of grim statistics released by the Centers for Disease Control and Prevention -- show that the flu has reached an epidemic level in the United States.
One of the strains making people sick this season has mutated, causing this year's vaccination less than optimal for protection.
"The most common virus that we're seeing this year is this H3N2 virus," said Michael Jhung of the CDC. "When we've seen H3N2 predominate in previous seasons, we've seen relatively severe seasons. So it's possible we could have a severe season again this year."
It's being felt widespread in at least 36 states with current influenza levels approaching peak levels we saw two years ago.
Doctors are seeing more patients, like Dr. Rahul Khare of Northwestern Memorial Hospital in Chicago.
"I was on a shift the other day, I saw about 35 patients. I saw about 10 positive flu swabs, and there were a couple of them I didn't even swab, I just treated them because it's just so prevalent."
The CDC is set to release its latest figures on how widespread the flu bug has become on Monday. In the meantime, officials still recommend getting a flu shot, even though it may not completely prevent against it. It may lessen the severity if you get sick.