Tick-borne viruses.
At least 38 viral species are transmitted by ticks. Virus-tick-vertebrate host relationships are highly specific and less than 10% of all tick species (Argasidae and Ixodidae) are known to play a role as vectors of arboviruses. However, a few tick species transmit several (e.g. Ixodes ricinus, Amblyomma variegatum) or many (I. uriae) tick-borne viruses. Tick-borne viruses are found in six different virus families (Asfarviridae, Reoviridae, Rhabdoviridae, Orthomyxoviridae, Bunyaviridae, Flaviviridae) and at least 9 genera. Some as yet unassigned tick-borne viruses may belong to a seventh family, the Arenaviridae. With only one exception (African swine fever virus, family Asfarviridae) all tick-borne viruses (as well as all other arboviruses) are RNA viruses. Tick-borne viruses are found in all the RNA virus families in which insect-borne members are found, with the exception of the family Togaviridae. 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). Key challenges are to determine the molecular adaptations that allow tick-borne viruses to infect and replicate in both tick and vertebrate cells, and to identify the principal ecological determinants of tick-borne virus survival.
Labuda
M
M
Institute of Zoology, Slovak Academy of Sciences, Dubravska cesta 9, 845 06 Bratislava, Slovakia. Milan.Labuda@savba.sk
Nuttall
P A
PA
D000357:African Swine Fever / Q000635:transmission / Q000821:virology; D000358:African Swine Fever Virus / Q000502:physiology; D000818:Animals; D001096:Arachnid Vectors / Q000821:virology*; D001102:Arbovirus Infections / Q000635:transmission / Q000821:virology*; D001103:Arboviruses / Q000502:physiology*; D006790:Host-Parasite Interactions; D006801:Humans; D012327:RNA Virus Infections / Q000635:transmission / Q000821:virology; D012328:RNA Viruses / Q000502:physiology; D017282:Tick-Borne Diseases / Q000635:transmission / Q000821:virology*; D013987:Ticks / Q000821:virology*