While the flu is picking up in the rest of the state - with seven flu-related deaths in people older than 50 this season - it's mild in North Idaho.
There have been no deaths up north, said Cynthia Taggart, a spokeswoman for the Panhandle Health District.
The last absentee-reports the district received from schools showed no increase, but those reports are two weeks old, she said Friday.
"With schools out, we have no absentee rates to pin flu trends on," she added. "Our epidemiologist tells me we've had sporadic activity, nothing alarming."
The flu is not a reportable illness, so plenty of people have symptoms and never visit a doctor or have a lab test, she said.
Doctors who see people with possible flu often diagnose them with it from the obvious symptoms, but don't follow up with tests to confirm it, Taggart said.
"We've heard from area labs of a few confirmed flus - the A virus," she said. "From that information, we're aware that the flu virus is here and earlier than usual."
Influenza took hold across Flathead County in the last week with flu cases doubling.
"We were slowing seeing cases," Jody White said. "We saw an exponential change in the last two weeks."
The number of confirmed influenza cases is 98, according to White, director of Community Health Services at the Flathead City-County Health Department.
For week ending Dec. 22, there were 25 reported cases. That grew to 44 the next week and then to 98.
"So we're starting to see more and more, which is typical, very typical for influenza, to start seeing that kind of a trend," White said. "It's a little bit earlier than usual to start seeing a spike in influenza cases, but not completely."
Taggart said flu shots remain available throughout the community and now is a great time to get one.
"It takes about two weeks for them to build up immunities once they're inside you," she said.
Flu season hits North Idaho hardest, typically, in late January through March, she said.
"We're about out of adult vaccine, but we have lots for children and some high-dose for people older than 64," she said.
Flu activity continues to increase in the U.S.
Most of the country is experiencing high levels of flu-like illness, according to the Centers for Disease Control and Prevention's latest "FluView" report.
"Reports of influenza-like illness are nearing what have been peak levels during moderately severe seasons," Dr. Joe Bresee, who is chief of the epidemiology and prevention branch in CDC's influenza division, said in a news release Friday.
The CDC continues to recommend influenza vaccination and antiviral treatment when appropriate at this time.
"While we can't say for certain how severe this season will be, we can say that a lot of people are getting sick with influenza and we are getting reports of severe illness and hospitalizations," Bresee said.
Twenty-nine states and New York City are now reporting high levels of influenza-like-illness, the CDC reported Friday.
Candace Chase of the Hagadone News Network contributed to this report.