Fairview Health Services is restricting visitors to its six Minnesota hospitals to reduce the spread of influenza, a sign that the virus has become more widespread as the state's 2013-14 flu season takes hold.

While exceptions will be considered for compassionate reasons, the health system is temporarily banning visitors younger than 5 and screening other visitors for influenza-like symptoms or for contact with people who have been sick.

"Visitors play an important role in the comfort, care, healing and well-being of our patients," said Steve Meisel, director of patient safety for Fairview, which operates the University of Minnesota Medical Center and other hospitals in Burnsville, Edina, Princeton, Wyoming and Hibbing. "At the same time, our patients may be particularly vulnerable to contracting the flu and, if they do, it could set back their recovery."

The restrictions, which will last for the duration of the winter, aren't unprecedented at this time of year, after the post-holiday spike in flu infections.

Influenza is considered widespread in Minnesota, according to the Minnesota Department of Health, as lab samples and other surveillance methods have detected the seasonal forms of the virus in the majority of the state.

The state recorded 144 flu-related hospitalizations last week — lower than the number from the first week of 2013, but much higher than in the five flu seasons before that.

Outbreaks reported in schools have been modest so far, and no flu-related deaths involving children have been confirmed yet, according to the Health Department.