Tick-Borne Encephalitis

January 2010

What is Tick-Borne Encephalitis?

Tick-borne encephalitis (TBE) is a viral disease that causes swelling of the brain (encephalitis), swelling of the membrane around the brain and spinal cord (meningitis), and/or swelling of the spinal cord (myelitis). It is transmitted through the bite of an infected tick.

 

 

 

 

Symptoms

• Usually take between 7 to 14 days to appear, but can take as long as 28 days.
• Take less time to appear if exposed through milk or milk products, i.e.: 3 to 4 days.
• Often present in two phases:
• in the first phase, symptoms are flu-like and include fever, malaise, headaches, nausea and vomiting.
• in second phase, symptoms involve the central nervous system and can include encephalitis (swelling of the brain), meningitis (swelling of the membrane around the brain and spinal cord), and/or myelitis (swelling of the spinal cord).
• In more severe cases, complications during the second phase may cause long term neurological damage or even death. Long-term effects can include:
• severe headaches
• memory loss
• lack of concentration
• decreased stamina
• depression
• loss of coordination
• tremors, and/or
• hearing impairment

Transmission

• TBE is spread through the bite of an infected tick, primarily of the Ixodes ricinus and Ixodes persulcatus species.
• Ticks that transmit TBE can be found particularly in woodlands and at woodland edges, in parks and where the countryside is moist and uncultivated, containing low brush and ground foliage.
• Ticks generally bite from April to November with peak biting activity in early and late summer (i.e.: May/June and September/October).
• TBE can also be transmitted through contaminated unpasteurized cow, sheep, or goat milk and milk products obtained from infected animals. 

Where is Tick-Borne Encephalitis a concern?

• TBE is found across Europe and Asia, from eastern France to Northern China and Japan. The geographical “belt” stretches across Russian and south to Albania.
• Countries recently reporting higher incidence of TBE include; Austria, Czech Republic, Estonia, Germany, Hungary, Latvia, Lithuania, Poland, Russia, Slovenia, Sweden and Switzerland.
• A map of countries and areas of risk for TBE is available from the website of the International Working Group on Tick-Borne Encephalitis.

Related Travel Health Notices

None.

Recommendations for Travellers

1. Follow personal protective measures to avoid tick bites
   1. Cover up:
      1. Wear long-sleeved, tucked-in shirts, long pants, shoes (not sandals) or boots.
      2. Smoothly woven clothing makes it more difficult for ticks to attach.
      3. Tape the cuffs of your pants or tuck them inside your boots or shoes.
      4. Treat your clothing with permethrin.
         • Permethrin isn't available in Canada, however, travel health clinics can advise you how to purchase permethrin and treat your clothing before or during your trip.
         • Permethrin-treated clothing is effective for up to two weeks or six washings.
   2. Use arthropod repellent on exposed skin:
      • Arthropod repellents that contain DEET are the most effective
      • Use as directed by the manufacturer
      • Do not apply to cuts, scrapes, abrasions or irritated skin
      • Do not spray directly on your face
      • Wash your hands after you apply repellent to avoid contact with your lips and eyes
      • Do not use products that contain both repellent and sunscreen
      • If you want to use sunscreen and an arthropod repellent with DEET, apply the sunscreen first.  Let it soak into your skin for about 20 minutes, then apply repellent with DEET
      • Wash off repellent at the end of the day, before you go to bed.

Additional information on avoiding arthropod bites…

2. Follow personal protective measures after high-risk activities:
   1. Check your skin and clothes for ticks:
      1. Ticks do not always begin feeding immediately after they attach themselves although transmission of the virus usually occurs early in the feeding process.
      2. Common areas to find ticks include the hair-line, behind the ears, on elbows, the backs of knees, the groin and/or armpits.
      3. The bite is painless and is often not noticed.
      4. An adult tick that has finished feeding may be as large as a coffee bean. Immature ticks are considerably smaller.
   2. Carefully remove any ticks you find:
      1. Use tweezers or blunt curved forceps to remove ticks.
      2. Grasp the tick as close to the skin as possible and pull steadily upwards without twisting or jerking.  This increases your chances of removing all of the tick.
      3. Do not use alcohol, matches or petroleum jelly (i.e. Vaseline) to remove ticks. 
      4. Do not handle ticks with your bare hands.
      5. The bite site should be disinfected after tick removal and you should wash your hands with soap and water.
      6. The date of the tick bite and the start of any symptoms should be documented.
      7. If any symptoms occur within 28 days of the tick bite see a doctor, nurse or health care provider immediately.
3. Consider getting vaccinated:
   

   Travellers who may be at risk should consult a health care provider to discuss the benefits of getting vaccinated.

4. Avoid unpasteurized milk and milk products.

Don't Forget…

1. Consult a doctor, nurse or health care provider or visit a travel health clinic at least six weeks before you travel.
2. What to do if you get sick when you are travelling.
3. What to do if you get sick after you return to Canada.
4. Know what vaccines you need and when to get them.

Other Related Information

• Committee to Advise on Tropical Medicine and Travel (CATMAT) – Statement on Tick-borne Encephalitis
• CATMAT – Statement on Personal Protective Measures to Prevent Arthropod Bites
• World Health Organization (WHO) – Vector-borne Viral Infections: Tick-borne Encephalitis
• International Scientific Working Group on Tick-borne Encephalitis – Endemic Areas 2009