Lyme disease, a supposedly rare disease in India, is caused by the spirochete Borrelia burgdorferi. It is a tick-borne disease that is transmitted by Ixodes tick. It is carried by mice, squirrels, birds, and mostly other small animals. Reportedly, 3000-5000 people in India suffer from the disease. It is very common in the United States. A study, by US researchers, published in PLOS Pathogens has found the genes that trigger severe symptoms in the disease. For the study, a total of 299 Lyme disease patients, from the northeastern and midwestern U.S., and central Europe, have been studied.