Both can be infected with and transmit Lyme disease. Deer ticks acquire the bacteria by feeding primarily on small mammals infected with the bacteria, particularly the white-footed mouse. Deer ticks infected with the bacteria that cause Lyme disease have been found in Illinois. However, Lyme disease has been reported in almost all states in the U.S. as well as in many countries throughout the world. Signs and symptoms can vary greatly from one person to another.
Symptoms also vary with the length of time a person has been infected.
A ring-like red rash occurs in about 60 percent of cases and begins three days to 32 days after the bite of an infected tick. The red rash at the bite site is circular and grows larger over a few days or a few weeks. In the center, the rash usually clears and has been described as resembling a bull's-eye. Generally, the rash is warm to the touch, but not painful. An allergic reaction to tick saliva can often occur at the site of the tick bite.