Viruses transmitted by ticks

Ticks transmit a wide variety of arboviruses (arthropod-borne viruses). Tick-borne viruses are found in six different viral families (Asfarviridae, Reoviridae, Rhabdoviridae, Orthomyxoviridae, Bunyaviridae, Flaviviridae) and at least nine genera. Some as yet unassigned tick-borne viruses may belong to a seventh family, the Arenaviridae. With only one exception (African swine fever virus) all tick-borne viruses (as well as all other arboviruses) are RNA viruses. Some tick-borne viruses pose a significant threat to the health of humans (tick-borne encephalitis virus, Crimean–Congo haemorrhagic fever virus) or livestock (African swine fever virus, Nairobi sheep disease virus). This chapter first considers the characteristics of ticks important in virus transmission and then presents an overview of the tick-borne members of different virus families