(WEATHER CHANNEL) The flu season is officially underway, marking the earliest start to widespread flu outbreaks in more than 15 years.
While flu season doesn't have a set start and end date, health officials consider it to kick off when a significant number of doctor's office visits are related to flu-like illnesses for three weeks in a row, according to the Associated Press. That threshold has now been met.
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Data from the U.S. Centers for Disease Control and Prevention shows that flu cases have risen steadily over the past few weeks and continue to increase.