| Abstrakt | | Tick-borne encephalitis (TBE) is the most important human virus infection of the central nervous system in Central Europe. TBE was clinically described in the Far Eastern Soviet Union in 1934. In 1937, Sielber established the characteristic features of the disease among patients in the eastern part of Siberia. He succeeded in determining the etiology of the disease and assumed that the tick Ixodes per-sulcatus was the vector of the isolated virus. The disease was first recognized in eastern Europe (Czechoslovakia) during an epidemic in 1948. and a virus isolated from a patient was shown to be similar to the Far Eastern virus. TBE viruses are antigenically closely related. On the basis of their geographic distribution, they are usually distinguished as either Central European subtype or Central European encephalitis (CEE) virus or Far Eastern subtype or Russian spring-summer encephalitis (RSSE) virus. The distribution of the two infections closely follows that of their arthropod vectors: Ixodes ricinus in the case of CEE and I persulcatus in the case of RSSE. The virus is maintained in nature in a cycle involving ticks and wild vertebrate hosts. Insectivores - shrews, moles, hedgehogs - and small rodents act as virus reservoirs. Viremia in these wild animals is high enough to infect ticks. By contrast in larue domestic animals, such as goats, sheep and cattle, viremia does not reach the threshold necessary for the transmission of the virus to ticks. However, these large animals serve as an amplifying host for the development of ticks and may thus indirectly contribute to the maintenance of the virus in nature. The virus is excreted in the milk and human infections rnay result from comsumption of unpasteurized goat or sheep milk or cheese. I ricinus and I persulcatus are the main vectors of TBE in Europe and the Far East, respectively. (Abstract truncated at 2000 characters)
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