Key points
- Tick-borne encephalitis virus mainly spreads through the bite of an infected tick. It can sometimes spread through consumption of unpasteurized milk or cheese from infected goats, sheep, or cows.
- Tick-borne encephalitis virus is not found in the United States.
- Initial symptoms can include fever, headache, vomiting, and weakness.
- Illness can be severe.
- There is a vaccine for tick-borne encephalitis that is recommended for some travelers.
Overview
Tick-borne encephalitis is a disease caused by a virus spread by infected ticks. 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. The ticks that spread tick-borne encephalitis virus are most active in warmer months (April through November).
Tick-borne encephalitis virus is not found in the United States.
Symptoms
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).
How it spreads
Tick-borne encephalitis virus spreads through the bite of an infected tick (family Ixodidae). Occasionally, tick-borne encephalitis virus can spread to people through eating or drinking raw milk or cheese from infected goats, sheep, or cows.
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.
Prevention
A vaccine for tick-borne encephalitis is available. Healthcare providers 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 preventing tick bites.
Testing and diagnosis
See your healthcare provider if you have symptoms after being exposed to ticks in an area where tick-borne encephalitis virus spreads.
Treatment
No medicines are available to treat tick-borne encephalitis virus infection. Rest, fluids, and over-the-counter pain medications may relieve some symptoms. People with severe disease often need to be hospitalized to receive support for breathing, staying hydrated, or reducing swelling in the brain.
For healthcare providers: Treatment and Prevention of Tick-borne Encephalitis