Lyme disease is caused by the bacterium Borrelia burgdorferi, and is transmitted to humans through the bite of an infected blacklegged deer tick. It is the most common tick-borne infectious disease in the United States. Untreated Lyme disease can produce a wide range of symptoms, depending on the stage of infection. Typical symptoms include fever, chills, headache, fatigue, muscle and joint aches, swollen lymph nodes, and a rash. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics. If left untreated, infection can spread to joints, the heart, and the nervous system; causing facial paralysis, severe arthritis, heart palpitations, and inflammation of the brain and spinal cord.
Lyme Disease. Centers for Disease Control (updated January 19, 2018), https://www.cdc.gov/lyme/index.html