Tick-borne infections.

Ticks, obligate, blood-sucking members of the order Acarina and class Arachnida, are the most common agents of vector-borne diseases in the United States. Ticks play an important role in transmitting viruses, bacteria, spirochetes, parasites, and rickettsia. This article reviews the epidemiology, microbiology, diagnosis, and treatment of the major tick-borne diseases in the United States.