Tick-borne viruses

By 1972 some 68 different viruses had been recorded from more than 80 tick species, 20 of which were believed to cause disease in man or domestic animals (Hoogstraal, 1973). Since the publication of Hoogstraal's review, many other viruses have been isolated from ticks though their role as causative agents of human, or animal, disease is often unknown or uncertain. Many areas of Europe remain poorly surveyed and more viruses are likely to be found.

Tick-borne encephalitis TBE

Tick-borne encephalitis (TBE) is the most important and widespread of the arboviruses transmitted by ticks in Europe; TBE is a member of the family Flaviviridae. Tick-borne encephalitis should be considered a general term encompassing at least three diseases caused by similar flaviviruses, whose range spans an area from the British Isles (Louping ill), across Europe, as central Europe tick-borne encephalitis transmitted mainly by Ixodes ricinus, to far-eastern Russia, as Russian spring-summer encephalitis, which is transmitted mainly by I. persulcatus. The three diseases differ in severity, with Louping ill being the mildest and Russian spring-summer encephalitis the most severe. Man is infected by the bite of infected ticks and, much more rarely, by ingestion of milk from infected domestic animals (Dumpis et al., 1999). The tick is both a vector and a reservoir host; once infected, it remains infected throughout its life, through its metamorphosis and transmits the virus to its progeny. Small rodents (field-mice or voles) are the prime vertebrate hosts.