Here's why flu cases are rising later this season, according to CDC data

States in the South and along the West Coast are seeing particularly high flu activity.

The flu is ramping up after a slow start to the season. 

Positive tests rose 12% for the week ending Dec. 21, compared to the week prior, according to data released Friday by the Centers for Disease Control and Prevention. More than 12,000 people were hospitalized from the virus, up from nearly 9,000 the week prior. 

“We’re seeing upticks in both our inpatient hospitalizations as well as our community based metrics such as percentage of emergency room visits and test positivity,” said Dr. Scott Roberts, associate medical director for infection prevention at Yale New Haven Health. “I certainly expect they’re going to continue to go up since we’re really entering flu season right now.” 

Typically, flu activity starts to pick up around Halloween and peaks in February. This year, however, the virus got off to a later start, with activity only just picking up in recent weeks.

It’s not clear why that is, Roberts said. 

https://www.nbcnews.com/health/cold-and-flu/why-flu-cases-rising-later-season-cdc-data-rcna185546

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