"Lyme disease is the most common tick-borne disease in the Northern Hemisphere. Borrelia is transmitted to humans by the bite of infected ticks belonging to a few species of the genus Ixodes ("hard ticks").[5] Early symptoms may include fever, headache, fatigue, depression, and a characteristic circular skin rash called erythema migrans. Left untreated, later symptoms may involve the joints, heart, and central nervous system. In most cases, the infection and its symptoms are eliminated by antibiotics, especially if the illness is treated early.[6] Delayed or inadequate treatment can lead to the more serious symptoms, which can be disabling and difficult to treat.[7] Lyme disease is a biosafety level 2 disease."
http://en.wikipedia.org/wiki/Lyme_disease