Tick-borne encephalitis (or TBE) is an infectious disease caused by the tick-borne encephalitis virus (TBEV). The disease is present in large parts of Europe, such as Hungary, the Czech Republic and Slovenia, but also in regions where hiking is common, such as southern Germany and Austria. In Belgium, studies on animals have shown that the virus has been present in our country for several years. However, as the number of infected ticks is probably very low, the disease in humans is very rare. In autumn 2018, tick-borne encephalitis was diagnosed for the first time in two people who were probably infected in Belgium. During the summer of 2020, three confirmed cases in individuals infected in Belgium were identified.
Tick-borne encephalitis infection is often asymptomatic (in about two thirds of cases) or causes a mild illness with flu-like symptoms (fever, fatigue, headache, lasting 5 days on average) that disappear spontaneously. However, after a period without complaints (from about a week to 20 days), some people may experience a second, more severe phase of the disease, with inflammation of the meninges or brain. The vast majority of these patients will recover completely, but 10% may have residual damage and 1-2% may die.
There is no specific treatment for tick-borne encephalitis and since it is a viral infection, antibiotics are not useful. As the virus is found in the salivary glands, infection can occur within minutes of the bite. Unlike Lyme borreliosis, the infection can therefore not be prevented by checking the body for tick bites after a stay in the wild and removing the tick quickly.
The disease can be prevented by vaccination. As infection with the virus is extremely rare in Belgium, it is currently not necessary to be vaccinated when going out in the wild only in Belgium. However, vaccination is recommended for travellers who go to an area or country at risk and who engage in outdoor activities (bivouacs, hikes, etc.). More information can be obtained from the Institute of Tropical Medicine.