The period from the moment of infection till the first clinical signs at tick-born encephalitis, constitutes from 7 days till 30 days (on the average 7-14). The beginning of tick-born encephalitis is often acute and characterized by temperature raise to 39-40ºC and cold fit. Patient can feel photophobia, pains in globes, in throat at swallowing and its redness. There are muscular pains (necks’, shoulders’, extremities’, thoracal and lumbar departments of back).