Pathogenesis (disease development)
Early summer meningoencephalitis is caused by the TBE virus (from the Flaviviridae family), which is transmitted by ticks. In rare cases, transmission may also occur through infected goat or sheep milk.
The main virus reservoir is small animal rodents of the forest and meadows. The viruses first infect the Langerhans cells in the skin and multiply in these cells. They also use them as a means of transport to the lymph nodes (first viremia phase/presence of viruses in the blood). During a second viremia, infection of the nervous system occurs. This leads to the neurological symptoms described in approximately 30%.
Etiology (causes)
Biographic causes
- Genetic predisposition: the risk of disease is probably dependent on genetic factors.
- Occupations – workers in forestry, agriculture and hunters.
Behavioral causes
- Residence in a TBE risk area and/or consumption of dairy products made from unpasteurized milk.
- Staying in forested areas without adequate clothing or repellent (insect repellent) protection (>90% of infections are acquired during recreation)
Risk groups (in the corresponding risk areas).
- Forester
- Farmers
- Kindergarten children in the forest kindergarten
- Forest workers
- Hiker
