LA CROSSE, Wis. -- -

There are still three months left in this year's flu season, but there have already been more cases this year then in the entire flu season last year.

Health officials say it's hard to track reasons behind the increase, but they are urging people to take the flu seriously.

Mayo Clinic Health System says it saw only one case at this time last year, but this year, it's already seen 85 cases.

Gundersen Lutheran Health System has also seen a large increase, going from one case last year to 80 cases this year.

The spike reflects what's happening across the state of Wisconsin.

Last year's flue season, the state saw just less than 400 cases of people going to an emergency room or being hospitalized for influenza.

Nurses with the La Crosse County Health Department say the state has already surpassed that number, and the season doesn't usually end until March.

"When it starts earlier, you expect it's going to last longer because it will generally go through those winter months when people are confined. So we're expecting to see a lot more cases this year than last year," said La Crosse County Health Department nurse Christine Berth.

The flu virus can be passed by touch.

Nurses say the virus can live on a surface for up to 24 hours.

People with the flu can also start spreading it before they show any symptoms.

Infection control specialists say the No. 1 way to stop the spread is to get the flu vaccine.

"I'm a little bit surprised by the number of hospitalized cases we've had and with the increase in the number of cases confirmed that we've seen at this point in the year. It's definitely an active season and definitely a season you want to make sure you have your flu shot," said Mary-Jo Stokes, infection prevention and control specialist with Mayo Clinic Health System.

Nurses say they're not sure why there are so many more cases this year.

But they are encouraging everyone who hasn't gotten their flu shot yet to go out and get one right away.

If a patient is scared of needles, nurses say the flu mist is an option.

It's available for anyone ages 2 to 49.