Lyme Disease: Lyme disease, sometimes referred to as Lyme infection, is a bacterial illness, transmitted to humans by the bite of deer ticks (Ixodes ticks) carrying a bacterium known as Borrelia burgdorferi. Symptoms and signs include a red bull's-eye rash and flulike illness in the early stages of Lyme disease. Doctors will treat primary or early Lyme disease with oral antibiotics including doxycycline, penicillins, or erythromycin.