Lyme disease infects those affected by it.
Lyme disease . The most common sign of infection is an expanding area of redness on the skin , known as erythema migrans , that begins at the site of a tick bite about a week after it has occurred . Approximately 25 -- 50 % of infected people do not develop a rash . Infections are most common in the spring and early summer . Some healthcare providers claim that it is due to ongoing infection ; however , this is not believed to be true .