Lyme disease (LD) is a multi-stage, multi-system bacterial infection caused by the spirochete Borrelia burgdorferi, a spiral shaped bacterium that is most commonly transmitted by a tick bite. The disease takes its name from Lyme, Connecticut, where the illness was first identified in the United States in 1975.
According to the Centers for Disease Control and Prevention (CDC), Lyme disease continues to be a rapidly emerging infectious disease, and is the leading cause of all insect-borne illness in the US. The number of annually reported cases has increased 25-fold since national surveillance began in 1982. Up to 23,000 infections have been reported in one year in the United States. The majority (95 percent) of cases are reported in Connecticut, Rhode Island, New York, Pennsylvania, Delaware, New Jersey, Maryland, Massachusetts, Maine, Minnesota, New Hampshire, and Wisconsin.