CDC reports single-week decrease in flu activity — but experts warn "an upsurge" could be on the way

Flu activity remains elevated in most of the country, but the latest data from the Centers for Disease Control and Prevention shows "a single week of decrease" for the first time in months. Despite the dip, experts say not to let your guard down just yet.

After several weeks of increases, the agency's weekly influenza report Friday showed some key indicators are down, but health officials say an "upsurge" is expected. 

"Folks try not to seek care during the holiday season, so we see these divots in the surveillance graphs each year, but it is very probable that during the next weeks, we'll see an upsurge of cases," said Dr. Eduardo Azziz-Baumgartner of the CDC's Influenza Division.