National Epidemiology
Lyme disease is the most common vectorborne disease in the United States. According to the Centers for Disease Control and Prevention (CDC), in 1996 there were 16,461 cases reported in the United States. The majority of cases have occurred in four endemic regions: the northeast, the mid-Atlantic, Minnesota/Wisconsin and California/Oregon. Most cases occur between May and August, the most active feeding period of the nymphal Ixodes ticks.
