Ability of Ixodes scapularis, Dermacentor variabilis, and Amblyomma americanum (Acari: Ixodidae) to Acquire, Maintain, and Transmit Lyme Disease Spirochetes (Borrelia burgdorferi)

The ability of the immature stages of three tick species from the southeastern United States to acquire, maintain, and transmit Borrelia burgdorferi was determined under laboratory conditions. Dermacentor variabilis (Say) and Amblyomma americanum (L.) acquired spirochetal infection as larvae, but infection in D. variabilis (9% infected) and A. americanum, (1% infected) was inefficient and short lived. In contrast, Ixodes scapularis Say infected as larvae maintained spirochetal infection transstadially, and infected I. scapularis nymphs transmitted spirochetes to hamsters in four out of four trials. Although I. scapularis was a competent laboratory vector, natural populations of this tick taken from white-tailed deer and white-footed mice in Alabama were not infected with spirochetes.