(CNN) It's official: This year's flu season is a record breaker.

There have been 21 weeks of elevated flu activity reported in the United States during the 2018-19 flu season, based on data from the weekly flu report released Friday by the Centers for Disease Control and Prevention.

That's one week longer than the previous 10-year high, which occurred in the 2014-15 season and lasted 20 weeks, according to CDC spokeswoman Kristen Nordlund.

"This season has been record-breaking in terms of duration," she said. The latest weekly report includes flu activity through the week ending April 13.

Typically, flu season begins in the fall and ends in the spring.

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