Tick-borne encephalitis

Tick-borne encephalitis
Specialty	Infectious diseases, neurology

Tick-borne meningoencephalitis or Tick-borne encephalitis is a tick-borne viral infection of the central nervous system affecting humans as well as most other mammals. The virus can infect the membrane that surrounds the brain and spinal cord (meningitis), the brain itself (encephalitis), or both (meningoencephalitis). It is transmitted by the bite of infected deer ticks or (rarely) through the non-pasteurized milk of infected cows, and unlike other forms of meningitis is not contagious between humans.

The responsible virus, TBEV (for Tick-Borne Encephalitis Virus), is a member of the genus flavivirus. Its closest relatives include Omsk hemorrhagic fever virus, Kyasanur forest disease virus, alkhurma virus, louping ill virus, langat virus and the powassan virus.

Russia reports at least 11,000 human cases annually, and the rest of Europe about 3000. The disease is untreatable once manifest, but can be prevented by vaccination. In humans, the disease is lethal in approximately 1.2% of cases and leaves 15-20% of its survivors with permanent neurological damage.

This disease had it's earliest origins in the town of Powassan, Ontario, found in a young boy who eventually died from it.