Tick-borne encephalitis Powassan

**Powassan encephalitis** is an acute infectious disease of humans caused by the Ixodid tick. Encephalitis, as they were called in ancient times, are not very common diseases, their frequency is less than 5% of all human vector-borne infections.

The most significant encephalitis for humans includes tick-borne encephalitis, spotted fever, tularemia, and adenoviral infections. Ticks are carriers of typhus and louse-borne typhus (eastern territory), Lyme disease, and borreliosis.

In this context, tick-borne encephalitis is of particular interest. The most famous of these is Lyme disease. This is a bacterial disease caused by the spirochete Borrelia burgdorferi. There are several types of Borrelia, for example B. recurrentis, B. valgensis, etc., but B. burgdorferi, B. afzelii, etc. play a major role in human pathology. Borrelia burgdorferi causes damage to the nervous system. Tick-borne (or tick-borne) encephalitis is a viral infection. In humans, there are three main forms - epidemic, meningeal and non-paralytic. However, after an episode of menigeal form, most patients become lifelong carriers of the virus.