The infection is transmitted to human via a bite from an infected ixodes tick. Less commonly the disease can be spread through drinking unpasteurised milk from infected animals, especially goats. The disease is maintained in the wild by birds, deer, rodents and sheep.
Tick-borne encephalitis can be found in the far eastern part of the former USSR and extending across into China. It can also be found in European Russia, Austria, Hungary, the Balkans, Czech Republic, Slovakia and Scandinavia where, it is mainly a disease of the forest. It occurs here from late spring until early autumn and outbreaks often follow a period when voles are numerous.
Most human infections are contracted during outdoor leisure pursuits such as forestry working, camping, rambling and mountain biking during tick season (spring to early autumn).
TBE produces clinical features similar to those of many other types of meningitis and/or encephalitis.
The disease may be restricted to the meninges (the membranes covering the brain and spinal cord), which usually leads to full recovery, but it may also affect the brain, the upper portions of the spinal cord and even the nerve roots. Severe disease can cause permanent neurological damage and some patients require long-term rehabilitation. About 1 in 100 patients will die from TBE.
No specific treatment is available for TBE.
Recommendations for Travellers
Bite avoidance must be emphasised to all travellers e.g. tucking socks into trousers, using gaiters, insect repellents and sticking to designated pathways.
Travellers may consider being vaccinated against TBE if they are risk of tick bites when working walking or camping in endemic areas. The vaccine available in the UK is called TicoVac and TicoVac Junior for children.