It is a good sign but the number of flu cases is still much higher than they were at this point in 2012.
The dominant flu strain is one that tends to make people sicker, especially the elderly.
Forty-eight states including Illinois are now reporting widespread flu.
The CDC reported that nine more children or teens have died of the flu, bringing the nation's total to 29 this season.
There is no way to know whether deaths this season will be higher or lower than usual, according to officials.
Health officials are still urging people to get a flu vaccine.
The demand for the vaccine in the Chicago-area is high but they are still available, a public health spokesperson said.