Hard ticks as vectors-some basic issues.

There are various arthropods (e.g. insects, chiggers, mites, ticks) that take one or more blood meals on terrestrial vertebrates in the course of their lifetime. Among them are ixodid ticks (Acari, Ixodidae), all of which are obligately hematophagous. Their parasitic lifestyle predestines them to act as transmitters or vectors of microparasites, often pathogenic to humans and/or domestic animals. The list of ixodid tick-borne pathogens is long, encompassing viruses, bacteria, protozoans, and nematodes. The present mini-review gives a brief overview of the most relevant biological attributes that make ixodid ticks very efficient vectors compared with other hematophagous arthropod taxa.