For those who are starting the new year with coughing, sneezing, fevers and body-aches, this won't come as a surprise.

Flu season is officially here.

Public health officials in North Idaho said Tuesday that an increasing number of people in the region are heading to doctors' offices seeking medical treatment for flu-like symptoms.

Lab tests in North Idaho and nationwide indicate that the predominant circulating virus at this time is H1N1, a strain that first emerged during the 2009 pandemic. It was formerly known as the swine flu.

"The virus hasn't really changed," said Jeff Lee, Panhandle Health District epidemiologist, in a press release.

H1N1 can affect anyone, but it tends to cause illness more often in young and middle-aged adults. The vaccines that are available this flu season target the virus.

Tana Gonser, a registered nurse and manager of emergency services at Kootenai Health, said they haven't yet seen a significant increase in patients showing up at the hospital's emergency department with flu-like symptoms, although some patients have tested positive for influenza. Most of those positive results occurred within the last week, Gonser said.

Between Nov. 29 and Dec. 28, Kootenai Health lab reported 10 positive influenza tests.

"Out of the 10 positive tests, there have been three hospitalizations and no deaths," reported Giovanna Santovito-Carducci, a registered nurse and the hospital's infection prevention coordinator.

In 2009, H1N1 caught the medical community by surprise. It began appearing in the United States in the spring, and the vaccine did not become available until October. When it did become available, the vaccine was limited to high-risk individuals only.

"It was alarming because we didn't know anything about it," said health district spokeswoman Cynthia Taggart.

Since then, the flu vaccine has targeted H1N1 each year.

Although it was widespread in 2009, the virus turned out to be less deadly that year than seasonal flu.

The annual U.S. seasonal death rate ranges from 17,000 to 52,000, with an average of 36,000 flu deaths each year.

In 2009, H1N1 contributed to between 8,870 and 18,300 deaths in the U.S.

"We don't want people to panic, but we want them to take it seriously," Taggart said.

The Idaho Department of Health and Welfare reported the state's first flu season casualty on Monday, an adult older than 60.

Last year, there were 35 flu-related deaths in Idaho.

The Associated Press contributed to this story.