(CNN) Between 6.2 million and 7.3 million people in the United States have developed the flu this season, according to data released Friday by the US Centers for Disease Control and Prevention.

This is the first time the agency has provided an in-season estimate of national flu cases.

The CDC also estimates that between 2.9 million and 3.5 million people have seen a doctor because of the flu since the season began in October. Between 69,300 and 83,500 people have been hospitalized because of the virus.

Thirty states have reported widespread flu activity, although flu is present in every state. Fifteen states reported high levels of flu activity as of the week ending January 5. That's four fewer states than the previous week.

The number of children who died of flu increased. Three children's deaths related to the flu were reported in the week ending January 5, bringing the pediatric death toll to 16 for this season, according to the CDC.