A child in Boone County contracted a mild form of the virus while helping an exhibitor at the DuPage County Fair last month.
To avoid getting the illness, health officials urge you to wash your hands after exposure to animals, not to take food or drinks into areas with animals, and avoid contact with animals if you have flu-like symptoms.
So far there have been more than a dozen cases of the swine flu in the U.S. this year.