Tick-borne rickettsioses

These diseases in humans are caused by infective organisms transmitted in the bite of a tick. Humans are dead-end or tangential hosts for tick-borne viruses and do not play a significant role in their natural maintenance and dissemination. The vertebrate host spectrum varies for each virus; generally, the host population comprises particular species of smaller vertebrates with high population-replacement rates, such as birds or rodents, but larger mammals also can become infected.