Lyme-Borrelia- Burgdorferi-IgG- antibodies test is used to diagnose Lyme disease in a person. The body produces antibodies IgG & IgM against Borrelia-Burgdorferi bacteria which cause the Lyme disease. The Borrelia-Burgdorferi bacteria enter the human body through a tick bite. The symptoms of the Lyme disease include fever, fatigue, headache, joint pain, skin rash in the shape of a bull’s eye around the tick bite. The serum IgG is detected as early as 2 weeks after onset of disease. If the Lyme disease is left untreated, it will affect the heart and the nervous system. You will only test positive for Lyme disease after four weeks of getting the infection.