Tick-borne bacterial diseases emerging in Europe.

Since the identification of Borrelia burgdorferi as the agent of Lyme disease in 1982, 11 tick-borne human bacterial pathogens have been described throughout Europe. These include five spotted fever rickettsiae, the agent of human granulocytic ehrlichiosis, four species of the B. burgdorferi complex and a new relapsing fever borrelia. We present these emerging diseases and focus on the factors that play a role in the recognition of new tick-borne diseases.