Prevention of tick-borne encephalitis (TBE)

Prevention of tick-borne encephalitis (TBE)

Learn how tick-borne encephalitis (TBE) can be prevented.

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How can tick-borne encephalitis infections be prevented?

Consult a health care provider or visit a travel health clinic 6 weeks before you travel.

The following precautions will help prevent illness.

Avoid tick bites

Protect yourself from tick bites in high-risk regions when doing activities in forests or overgrown areas. You should:

  • wear closed-toe shoes, long-sleeved shirts and pants
  • pull your socks over pant legs
  • wear light-coloured clothes to spot ticks more easily
  • use insect repellent containing DEET (an active ingredient to keep bugs away) or Icaridin (always follow directions)
  • shower or bathe within 2 hours of being outdoors to wash away loose ticks
  • do a daily full-body check for ticks on yourself, children and pets
  • stay on designated hiking trails

Common areas to find ticks on your body include:

Keep your pets out of the woods, particularly dogs. Talk to your veterinarian about tick repellents for your pets.

Avoid unpasteurized milk and milk products

Infected cows, sheep and goats can transmit infection in their milk. However, pasteurization will minimize risk of infection from these products.

Vaccination

A vaccine against TBE does exist but is only available in countries where the disease is present. Travellers at high risk can consult a health care provider at their destination to discuss the benefits of getting vaccinated.

What should I do if I have been bitten by a tick?

Ticks attach themselves to the skin. Carefully remove attached ticks that you find. Document the:

  • date of the tick bite
  • start of any symptoms, if they appear

www.canada.ca

For health professionals: Tick-borne encephalitis (TBE)

Find detailed information on tick-borne encephalitis (TBE) for health professionals.

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What health professionals need to know about tick-borne encephalitis

TBE virus is caused by a single-stranded ribonucleic acid (RNA) virus from the family Flaviviridae. There have been 3 sub-types identified:

TBE virus is transmitted through the bite of an infected tick, primarily of the Ixodes ricinus and Ixodes persulcatus species.

Clinical manifestations

Approximately 2 out of 3 cases of TBE infection are asymptomatic. When you have symptoms of TBE, the illness typically has a biphasic course.

The first phase is associated with symptoms like:

The listed symptoms usually resolve within 1 week and correlate with viremia. They are also frequently subclinical or present as a nonspecific illness.

This phase is followed by a temporary remission lasting approximately 1 week.

There is a second neurologic phase after the virus has spread to the central nervous system. This happens in 20% to 30% of individuals. The second stage presents as aseptic meningitis (especially in children) or:

  • encephalitis
  • myelitis
  • radiculitis
  • some combination

Studies of patients with neurologic illness report that, overall, approximately:

  • 50% have meningitis
  • 40% have meningoencephalitis
  • 10% have meningoencephalomyelitis

European variety

The European sub-type is associated with milder disease with:

  • 20% to 30% of patients experiencing the second phase
  • mortality rates of 0.5% to 2%
  • severe neurological sequelae in up to 10% of patients

In children, the second phase of illness is usually limited to meningitis. However, adults older than 40 years are at increased risk of developing encephalitis. This is linked to higher mortality and long-lasting sequelae in those over the age of 60.

Far Eastern variety

The far eastern sub-type is associated with more severe disease (monophasic illness) with:

  • no asymptomatic interval preceding the onset of neurological disease
  • mortality rates of up to 35%
  • higher rates of severe neurological sequelae

Siberian variety

The Siberian sub-type is associated with a less severe disease with a fatality rate of 1% to 3%. There is a tendency for patients to develop chronic or extremely prolonged infections.

Diagnosis

The diagnosis is usually based on:

  • history of exposure to ticks within the previous 4 weeks
  • clinical symptoms
  • specific IgM and IgG antibodies to TBE, as measured by enzyme-linked immunosorbent assay (ELISA)

Antiviral antibodies are usually detectable at the beginning of the second phase.

Other specific tests are:

  • nested reverse transcriptase polymerase chain reaction (nRT-PCR) to detect virus-specific nucleic acid
  • western blots, performed in specialized laboratories

Treatment

There are no effective antiviral drugs for TBE. Therefore, treatment consists of supportive care.

www.canada.ca

Tick-borne Encephalitis Vaccine

Tick-borne encephalitis (TBE) is an acute viral illness caused by two closely related viruses of the family Flaviviridae: the central European encephalitis (CEE) virus, found in many European countries, and the Russian spring-summer encephalitis (RSSE) virus, found predominantly in the Asian parts of the former Soviet Union. These viruses, which are endemic to forested areas, are transmitted by ticks. In addition to humans, they infect small mammals and, to a lesser extent, birds. In Asia, the disease is characterized by abrupt onset of fever, severe headache, nausea and vomiting and severe back pain often associated with focal epilepsy and flaccid paralysis, especially of the shoulder girdle. Such paralysis may be permanent. The central European form of the disease has a longer course, often with biphasic fever, but severe sequelae are less frequent. The initial febrile stage is normally not associated with disease of the central nervous system, but the second phase, following approximaely 4-10 days after apparent recovery, is characterized by fever and meningoencephalitis. The case-fatality rate is approximately 20% for the Asian form of the disease and 1-5% for the European form.

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TBE is endemic to most European countries, the Russian Federation and possibly China. It is the most important arthropod-transmitted viral disease in Europe, and in some countries it represents a major public-health problem. The disease has been known by several names, including RSSE, Far Eastern encephalitis and CEE.

CEE virus is found is every European country, with the exception of Belgium, Luxembourg, the Netherlands, Portugal, Spain and the United Kingdom, and is transmitted primarily by the tick Ixodes ricinus. RSSE virus is most prevalent in the eastern part of the former Soviet Union and is transmitted by the tick Ixodes persulcatus.

Flaviviruses are a large group of small, enveloped viruses responsible for a number of severe human diseases, including yellow fever, Japanese encephalitis, dengue haemorrhagic fever and TBE. TBE virus particles are roughly spherical in shape, 40-50nm in diameter, and contain a core, 20-30nm in diameter. The genome consists of single-stranded positive-sense RNA with a relative molecular mass of about 4×10(6). Three structural proteins and the capsid, membrane and envelope proteins are all encoded by the viral genome. The envelope glycoprotein induces neutralizing and haemagglutination-inhibition antibodies and is the most important antigen for providing protection from disease.

The first vaccine against TBE was prepared in 1941 in the brains of mice. Some 20 years later TBE vaccines derived from cell cultures (chicken embryo fibroblast cells) were developed and used for active immunization in humans in the former Soviet Union. Later, a purified, inactivated virus vaccine was developed which proved to be more immunogenic than previous TBE vaccines.

The efficacy of these vaccines has been well documented. They have also been shown to protect mice from a lethal challenge with several TBE-virus isolates obtained over a period of more than 30 years from all over Europe and the Asian part of the former Soviet Union. In addition, it has been demonstrated that antibodies induced by vaccination of human volunteers neutralized all tested isolates.

Large outbreaks of TBE, sometimes involving thousands of cases, continue to occur in endemic areas. In addition, certain special groups, such as forest workers, geologists, travellers to endemic areas and laboratory workers, are also at risk. In view of the need to immunize large numbers of people, requirements for inactivated TBE vaccine have been formulated. In drafting these requirements, account has been taken of the regulations and requirements for the manufacture and control of TBE vaccines that have already been established in several countries.

www.who.int

Tick-borne Encephalitis

Vaccine

The vaccine should be offered only to at-risk travellers.

Western European vaccines:

In western Europe, two vaccines are available in both adult and paediatric formulations. Although these vaccines are based on the European subtype, immunity is induced against all subtypes of the TBE virus. The vaccines contain a suspension of purified TBEV grown on chick embryo cells and are inactivated with formaldehyde. Both TBE vaccines provide safe and reliable protection.

Little information is available on the duration of protection following completion of the primary three-dose immunization.

Outside countries or areas at risk, TBE vaccines may not be licensed and will have to be obtained by special request.

The two inactivated TBE vaccines manufactured in the Russian Federation are based on the Far Eastern subtype of the virus and propagated in primary chicken embryo cells. These vaccines are considered efficacious for individuals aged ≥3 years although supporting data are more limited for the Russian products.

Adverse reactions

With the western European vaccines, adverse events are commonly reported, including transient redness and pain at the site of injection in ≤45% of cases and fever ≥38 °C in ≤5–6%. However, none of these events is life-threatening or serious.

Both the Russian vaccines have been reported to be moderately reactogenic but without inducing severe adverse reactions. (However, some lots of the Russian vaccine Encevir were recently withdrawn because of frequent high fever and allergic reactions, particularly in children; this vaccine is currently not recommended for individuals 3–17 years of age.)

Type of vaccine: Killed

Number of doses: Western European vaccines: primary series, three i.m. doses, administered at intervals of 4–12 weeks between the first and second, and 9–12 months between the second and third doses.
Russian vaccines: primary series, three doses administered at intervals of 1–7 months between the first and second, and 12 months between the second and third doses.

Boosters: Western European vaccines: In healthy individuals aged

Accelerated schedules for travellers: depending on the choice of TBE vaccine, the manufacturer recommends either a rapid schedule based on immunization on day 0, day 14 and month 5–7, or an accelerated schedule based on immunization on day 0, day 7 and day 21. Russian vaccines: Booster doses are recommended every 3 years for those at continued risk of exposure.

Contraindications: Hypersensitivity to any vaccine component; adverse reaction to previous dose

Before departure: Second dose 2 weeks before departure

Recommended for: High-risk individuals only

Special precautions: Prevent blood-feeding ticks from becoming attached to the skin through use of appropriate clothing; remove ticks as soon as possible

www.who.int

Tick-borne encephalitis Vaccination

Is there a shot for tick-borne encephalitis?

For protection from tick-borne encephalitis (TBE) you will need three doses of the TBE vaccine. These doses need to be taken over a period of five to fifteen months.

There is a booster for tick-borne encephalitis, which can be taken every three to five years depending on your age. Ask your travel health nurse if this is appropriate for you.

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About tick-borne encephalitis

The majority of tick-borne encephalitis (TBE) cases are caused by an often painless bite by an infected ixodes tick. The virus is transferred via the tick’s saliva. A small number of people have picked up TBE by drinking unpasteurized milk or eating dairy products from an infected goat.

While the tick bites may be painless, the viral infection can result in encephalitis, which affects the brain and spinal cord and can cause permanent neurological damage or death.

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The World Health Organization says that 10,000–12,000 cases annually is a conservative estimate.

Symptoms of TBE

The flu-like symptoms of TBE emerge within two weeks of infection and include nausea, lethargy and muscle pain. This flu-like illness lasts around eight days and you can expect to make a full recovery.

If the infection progresses to encephalitis (brain swelling), paralysis or even death can result. Encephalitis is a medical emergency and you need to go to hospital if you have these symptoms:

  • confusion or drowsiness
  • seizures
  • photophobia
  • paralysis
  • speech problems

With proper care patients do recover, but it may take months or years to get completely better. One in ten patients who progress to encephalitis will suffer long-term cognitive difficulties. And about 1% cases are fatal.

Flu-like symptoms that arise within a few weeks of your return from an area where you can catch TBE are a cause for concern and you should get medical advice.

Which travellers are more likely to catch TBE?

If you will be in an affected area from late spring to early fall, whether for fun (camping, hiking or walking) or work (with forestry or agriculture), speak to your healthcare provider about vaccination before travelling to the area.

Countries with a risk of tick-borne encephalitis

TBE can be contracted in the forested areas of Austria, the Balkans, the Czech Republic, European Russia, Hungary and Slovakia, as well as in the forests of Scandinavia. It is also present in the far eastern parts of the Russian Federation, Mongolia and northern China. The greatest risk is from late spring until early fall.

Prevention

Avoid bug bites by using insect repellent, wearing protective clothing and covering as much of the body as possible (wearing hats and tucking pant legs into socks). Generally, ticks prefer long grass and vegetation, so it’s best to stay on cleared paths and avoid overgrown trails.

If you do find a tick on yourself, make sure to promptly and carefully remove it without squeezing the bug’s body and without separating the head from the body – you do not want to leave the head embedded in your flesh.

The virus may even be picked up from drinking unpasteurized milk, so it’s best to avoid that.

www.canadiantravelclinics.ca

Tick-E-Vac: tick-borne encephalitis vaccine

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Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People

Tick-borne Encephalitis

What is tick-borne encephalitis (TBE)?

Tick-borne encephalitis (TBE) is an illness caused by a virus spread through tick bites. You can also get TBE by eating or drinking unpasteurized dairy products (such as milk and cheese) from infected goats, sheep, or cows.

Symptoms include fever, achiness, loss of appetite, headache, nausea, and vomiting. Swelling of the brain and/or spinal cord, confusion, and sensory disturbances occur in 20-30% of people with TBE. One percent of people die from this infection.

Who is at risk?

TBE is found in many parts of Europe and Asia (from eastern France to northern Japan and from northern Russia to Albania). Several thousand cases are reported each year, but there are probably many other cases that do not get reported. The highest number of cases occurs in Russia. Other countries with high risk for disease are Czech Republic, Estonia, Germany, Hungary, Latvia, Lithuania, Poland, Slovenia, Sweden, Switzerland, China, Japan, Mongolia, and South Korea. Travelers are more likely to get TBE from April through November (mostly in early and late summer) and when traveling to forested areas where ticks are common.

What can travelers do to prevent TBE?

There is no vaccine that prevents TBE that is available in the United States, but it is available in some other countries. Travelers anticipating high-risk activities may consider being vaccinated in Canada or Europe. High-risk activities include working or camping in forested areas or farmland, adventure travel, or living in countries where TBE is present for an extended period of time.

All travelers should take these steps to prevent TBE:

wwwnc.cdc.gov

TicoVac (tick-bourne encephalitis vaccine)

Find out when this vaccine is recommended, how it’s given and what side effects it might have

What is TicoVac used for?

  • Preventing tick-borne encephalitis (TBE). TBE is an illness affecting the brain that is caused by infection with a virus carried by ticks. This virus is transmitted by bites from ticks found mainly in rural areas of Russia, Central and Eastern Europe and Japan.

The vaccine is recommended for adults and children from one year of age who are travelling to high-risk areas, for example people working outdoors, walking or camping in warm forested areas of Central and Eastern Europe, Scandinavia, Northern and Eastern China and parts of Japan, particularly from April to November when ticks are most prevalent.

How does TicoVac work?

TicoVac contains inactivated tick-borne encephalitis virus. The vaccine works by stimulating the body’s immune response to this virus, without actually causing the disease.

When the body is exposed to foreign organisms such as viruses, the immune system produces antibodies against them. Antibodies help the body recognise and kill the foreign organisms. The antibodies remain in the body to help protect the body against future infections with the same organism. This is known as active immunity.

The immune system produces different antibodies for each foreign organism it encounters. This establishes a pool of antibodies that helps protect the body from various different diseases.

This tick-borne encephalitis vaccine stimulates the body to produce antibodies against the virus that causes tick-borne encephalitis. This means that if you are bitten by a tick that carries this virus the antibodies you have already produced can protect you from getting this illness.

How is TicoVac given?

  • The vaccine is given by injection into a muscle of the upper arm for adults and older children, and the thigh for young children.
  • Two doses of the vaccine provide protection in 90 per cent of people for one tick season and the course should ideally be completed at least one month before travel. The second dose is given between one and three months after the first dose (but if necessary can be given after 14 days).
  • A third dose should be given 5 to 12 months after the second dose. Almost 100 per cent of people should be protected for three years after three doses.
  • Some vaccines remain effective for a lifetime, while others have to be updated after a few years. The three initial doses of this vaccine provide immunity against tick-bourne encephalitis for three years, after which time a booster dose will be needed to provide continued protection. Further boosters may then be needed every three years to provide continued immunity. This can be checked by measuring the levels of antibodies in the blood.
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What should I know before having the Ticovac vaccine?

  • People over 60 years of age and people who have an underactive immune system, for example due to a genetic defect, disease such as HIV infection, or treatment with immunosuppressant medicines such as chemotherapy, high-dose corticosteroids, or immunosuppressants, for example used following an organ transplant, may not produce an adequate number of antibodies in response to this vaccine. As a result, the vaccine may be less effective in these people. Your doctor may want to take a blood test to measure the level of antibodies in your blood four weeks after your second dose, and give another dose if you haven’t produced enough antibodies at this time. The third dose should then be given as normal. If you have previously had a vaccine against Japanese encephalitis, yellow fever or Dengue virus, you should let your doctor know, because these can affect the results of blood tests to check for antibodies.
  • As with all vaccines, this vaccine may not produce immunity in 100 per cent of people given the vaccine. You are less likely to be protected if the three doses of the vaccine are given at longer intervals apart than is recommended.
  • Tick bites can also cause infection with Borrelia bacteria, which cause Lyme disease. This vaccine only protects against infection with the tick-borne encephalitis virus, and does not provide protection against Borrelia infection and Lyme disease.

Who should not have the TicoVac vaccine?

  • People who have ever had a severe allergic reaction (anaphylaxis) to latex, eggs or chicken.
  • People allergic to formaldehyde, neomycin, gentamicin, protamine sulfate or any other ingredient used in the manufacture of the vaccine. (The person administering the vaccine can give you this information.)
  • People with a sudden feverish illness. (The vaccine should be postponed until after recovery.)
  • Babies under one year of age.

TicoVac should be used with caution in

  • People with a non-severe allergy to eggs or an allergy to latex.
  • People with diseases caused by the body’s immune system attacking healthy body tissue (autoimmune diseases, eg rheumatoid arthritis, multiple sclerosis).
  • People with brain disorders such as epilepsy.
  • Children with a history of fits associated with fever (febrile convulsions), or a history of a very high temperature (fever) following vaccinations. This is because the vaccine can cause fever in children, particularly in young children after the first dose. Your doctor may recommend that you give your child a medicine such as paracetamol to prevent fever or lower the child’s temperature if they get a fever after having this vaccine. Ask your doctor or pharmacist for advice.

Can I have the Ticovac vaccine while pregnant or breastfeeding?

Certain vaccines should not be used during pregnancy or breastfeeding. However, other vaccines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before having any vaccine.

  • The safety of this vaccine during pregnancy and breastfeeding has not been studied. Inactivated vaccines like this one are usually considered safe to use in women who are pregnant or breastfeeding. However, the manufacturer states Ticovac should only be given if considered essential by your doctor, and the potential benefits are considered to outweigh any risks to the baby. It is important to get medical advice from your doctor before having this vaccine if you are or think you could be pregnant, or you are breastfeeding.

What are the possible side effects of TicoVac?

Vaccines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this vaccine. Just because a side effect is stated here does not mean that all people having this vaccine will experience that or any side effect.

Very common (affect more than 1 in 10 people)

  • Pain or tenderness at the injection site.

Common (affect between 1 in 10 and 1 in 100 people)

  • Headache.
  • Feeling sick or vomiting.
  • Aching muscles or joints.
  • Feeling tired or generally unwell.
  • Fever (high temperature) in children, particularly younger children — see cautions above.
  • Loss of appetite in children.
  • Restlessness or difficulty sleeping in children.
  • Swelling, redness or hardening of skin at the injection site in children (this is rare in adults).

Uncommon (affect between 1 in 100 and 1 in 1000 people)

  • Swollen glands.
  • Fever in adults.

Rare (affect between 1 in 1000 and 1 in 10,000 people)

  • Dizziness or spinning sensation.
  • Sleepiness in adults.
  • Visual disturbances.
  • Sensation of ringing or other noise in the ears (tinnitus).
  • Increased heart rate (tachycardia).
  • Shortness of breath.
  • Diarrhoea.
  • Rash or itching.
  • Musculoskeletal stiffness.
  • Aggravation of autoimmune diseases.
  • Disorders of the nervous system.
  • Convulsions.
  • Allergic reaction.

If you think you have experienced a side effect from a vaccine you should get advice from your doctor, nurse or pharmacist. If they think it’s necessary they’ll report it for you. Did you know you can also report side effects yourself using the yellow card website ?

Can the Ticovac vaccine affect other vaccines or medicines?

The tick-bourne encephalitis vaccine is not known to affect other medicines.

However, people taking medicines that suppress the activity of the immune system, such as chemotherapy, high-dose corticosteroids, or immunosuppressants (for example used following an organ transplant), may not produce adequate numbers of antibodies in response to this vaccine. As a result, the vaccine may be less effective in these people.

If other vaccines are given at the same time as this one they should be administered into a separate site and preferably into a different limb.

www.netdoctor.co.uk

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