Key points
- Tick-borne encephalitis virus is mainly spread through the bite of an infected tick.
- Tick-borne encephalitis is not found in the United States.
- Initial symptoms can include fever, headache, vomiting, and weakness.
- Disease can be severe.
- A vaccine for tick-borne encephalitis is available and is recommended for some travelers.
Overview
Tick-borne encephalitis virus is spread through the bite of an infected tick. Occasionally, tick-borne encephalitis virus can spread to people through eating or drinking raw milk or cheese from infected goats, sheep, or cows.
Tick-borne encephalitis virus can be found in parts of the region stretching from western and northern Europe to northern and eastern Asia. People who travel to these areas might be at risk for infection. Tick-borne encephalitis virus is not found in the United States. The ticks that spread tick-borne encephalitis virus are most active in warmer months (April through November). People who spend time outdoors in or near forests are at highest risk of being bitten by a tick infected with tick-borne encephalitis virus.
Many people infected with tick-borne encephalitis virus do not have symptoms. Initial symptoms can include fever, headache, vomiting, and weakness. Severe disease often occurs including inflammation of the brain (encephalitis) or the membranes around the brain and spinal cord (meningitis).
There are no medications to treat tick-borne encephalitis. A vaccine for tick-borne encephalitis is available and might be recommended for some U.S. travelers who are visiting parts of Europe and Asia where tick-borne encephalitis is found and who might be at risk of exposure to ticks while participating in outdoor activities. You also can reduce your risk of infection from tick-borne encephalitis virus by avoiding ticks.