Minnesota appears to be in the midst of the worst flu outbreak since the 2009 H1N1 pandemic, health officials said Wednesday.

A record number of children -- 123 -- tested positive for the flu at Children's Hospitals and Clinics of Minnesota in the first week of January, and 16 were hospitalized, according to Patsy Stinchfield, the director of infectious diseases.

The numbers, she said, are higher "than our highest week in the H1N1 pandemic."

Meanwhile, local clinics are reporting a surge in demand for flu shots following news reports that two teenagers have died in Minnesota of complications of the flu in the past two weeks.

New statewide numbers are expected to be released Thursday, but one Health Department official said Wednesday that more than 900 people have been hospitalized so far this season -- a big spike just in the past week. By comparison, only 552 people were hospitalized in Minnesota during the entire last flu season.

"This thing has really spread like wildfire," said Dr. Gregory Poland, a flu specialist at the Mayo Clinic.

As recently as last week, state health officials were saying that this year's outbreak was simply off to an early, but not unusual, start. But now, Minnesota may be "on track for what we saw during the pandemic," said Kris Ehresmann, who oversees the infectious disease program at the Minnesota Department of Health. "And it's not slowing down."

In 2009, more than 1,700 people were hospitalized in Minnesota when a new flu strain spread around the globe. Most cases, however, were relatively mild.

This year, "the kids we're seeing seem to need more [medical care]," Stinchfield said. "They just seem to be sicker kids."

She noted that Children's has stopped testing every patient with flu symptoms because it's running low on rapid-influenza test kits, which are reportedly in short supply around the country.

The flu is now widespread in more than 40 states, according to federal officials, and numbers have been rising for the past month.

About 5.6 percent of all doctor visits in the United States now are for influenza, according to the U.S. Centers for Disease Control and Prevention. That compares with 2.2 percent at the peak of the season last year.

In Boston, officials declared a health emergency Wednesday and started offering free flu shots in the face of an escalating number of cases.

Most people have been infected by a particularly severe strain of flu known as H3N2.

On Tuesday, a 14-year-old St. Louis Park girl died of complications of the flu, the second apparently otherwise healthy teenager to succumb to the disease in 10 days. In December, a 17-year-old Texas teenager died at Regions Hospital in St. Paul after he fell ill while visiting relatives.

'Throwing up is gross'

By Wednesday, clinics throughout the Twin Cities were reporting an increase in calls about flu shots. One Fairview clinic had to reassign a nurse to handle the flood of requests, while Children's reported an uptick in flu-shot requests throughout its hospitals and clinics.

At the Target Clinic in Roseville on Wednesday evening, teenagers and their parents spilled out of the small, open lobby waiting to get shots from the nurse practitioner on duty.

Jon Edin, 47, of Roseville, brought his son Erik, 15, after reading about the local deaths and the Boston outbreak.

"We've been meaning to do it, and the news was the thing that pushed us over the edge," Jon Edin said. "Might as well be careful."

"And throwing up is gross," said Erik Edin, a ninth-grader at Roseville High School. "I'd rather not be sick this season."

Nearby, Heidi Bentz of Roseville waited with her children -- Calvin, 15, and Kaitlyn, 12. Bentz said she got her flu shot a few days ago, but she came back with her kids after word spread about the students' deaths.

"It's on Facebook, on the news, all the talk at school," she said. "It's scarier as you're hearing more about it."

Rising demand at U

Dave Golden, director of public health at the University of Minnesota's Boynton Health Service, said despite the winter break, the U has seen an uptick in vaccinations. The U doesn't generally conduct walk-in clinics during January but is doing so now to meet demand. "Tragedy hits and people will respond," Golden said.

The U will decide whether to take any additional measures before students return from break. In the meantime, they'll be encouraging students to get shots, despite some concerns about the vaccine. "We know it's not 100 percent [effective], but we know it's better than not being vaccinated," Golden said.

Also Wednesday, a Mayo Clinic spokesman urged Minnesota employers to consider modifying their sick-leave policies so that employees don't have to venture out and get a doctor's note to miss work.

For many parents, the news of recent flu deaths "was a wake-up call," said Ehresmann of the Health Department.

At the same time, she said such deaths can occur in any flu season. "I don't want to minimize it; it just makes me sick that this happened," she said.

She said the best way to fight the flu, in addition to flu shots, is to encourage people to stay home if they're sick.

"You may think it won't affect anybody else, but you don't know," she said. "We just don't know who we're potentially infecting and what kind of a devastating effect we can have on them."

Bloomberg News contributed to this report. mlerner@startribune.com • 612-673-7384 asimons@startribune.com • 612-673-4921