TBE: tick-borne tick-borne encephalitis

Tick-borne encephalitis (TBE) is transmitted by ticks infected with a specific virus. In most cases, TBE is mild, and the symptoms are similar to the flu. The disease rarely takes a severe course and can even lead to death. But what exactly is TBE? What risk areas, when does vaccination make sense, and what are the side effects? Below, you will find everything you need about tick-borne encephalitis and the TBE vaccination.

What is TBE?

The abbreviation TBE stands for tick-borne encephalitis. The disease is an inflammation of the brain, meninges and spinal cord. The areas can be affected individually but also all together.

TBE is triggered by a viral pathogen that belongs to the flaviviruses and is related to the pathogens that cause yellow and dengue fever. The virus is usually transmitted through tick bites (colloquially incorrectly referred to as tick bites). TBE infections rarely occur after consuming raw milk from sheep, goats or cows. TBE cannot be transmitted from person to person, so the disease is not contagious.

The older the affected person is, the higher the risk of a severe course of the disease. An infection with TBE can leave permanent damage and even be fatal.

 

TBE: Symptoms and first signs

Not every infected tick transmits the pathogen to humans. If there is a transmission, it takes one to two – but at most four – weeks before symptoms appear. This phase is called the incubation period.

The first symptoms of TBE can be compared to those of flu:

• Fever
• headache and body aches
• nausea or vomiting
• dizziness
• Worsened general condition (e.g. exhaustion, loss of appetite )

About nine out of ten people who get sick either have no symptoms at all, or the symptoms only last a few days – the infection is then over after about a week. In children, in particular, it usually resolves without complications.

Severe course of TBE

In about ten per cent of those affected by TBE, however, the fever rises again after a symptom-free period, leading to a second phase of the disease. In these cases, the virus can cause impairments in different areas of the central nervous system. Meningitis (inflammation of the meninges), encephalitis (inflammation of the brain) or meningoencephalitis (inflammation of the meninges and brain) usually occurs.

In rare cases, the spinal cord is also affected. Then, one speaks of meningoencephalomyelitis. Isolated inflammation of the spinal cord is extremely rare.

Severe courses affect older people in particular.

 

What are the symptoms of the severe course of TBE?

The symptoms of a severe course depend on which areas are affected by the inflammation:

• Some symptoms of meningitis are more diffuse, including fever, headache, and nausea. Increased sensitivity to light and a rigid neck are characteristic. The latter is typical of meningitis. The muscles of the neck are tense and painful. Therefore, the chin cannot be lowered to the chest. Meningitis caused by the TBE virus usually has very pronounced symptoms.
• In combination with encephalitis, the symptoms become even more severe. Symptoms of coordination and paralysis, as well as tremors and seizures, can occur. Hearing and swallowing problems are also possible.
• The symptoms are even more severe if the spinal cord is also affected. In this case, paralysis of the arms, legs, neck and face muscles can occur. Respiratory paralysis, which is also possible, is life-threatening.

How is tick-borne encephalitis diagnosed?

The first step in the diagnosis is an anamnesis interview. The doctor will ask whether there was a tick bite and whether there is a TBE vaccination. As a rule, TBE is diagnosed with the help of blood tests because, in addition to various inflammatory parameters, there are usually specific antibodies against TBE in the blood.

This is usually immunoglobulin M, or IgM for short, a particular antibody subgroup. The IgM antibodies may not be elevated in rare cases despite an infection. Then, if TBE is suspected, a possible increase in IgG antibodies is checked over two weeks. In addition, an examination of the spinal cord and cerebrospinal fluid can also be carried out, and imaging methods can be used.

An early diagnosis of TBE is advantageous, as timely treatment can help to prevent long-term damage and long-term effects.

Every TBE infection is notifiable. The health department must be informed of the disease 24 hours after diagnosis.

Treatment of TBE

There are no drugs that fight the TBE virus. This makes treatment difficult. In contrast to Lyme disease, also transmitted by ticks, TBE can not be cured with medication.

Therapy is only symptomatic. In addition to drugs such as anticonvulsants and painkillers, non-drug measures such as physiotherapy or speech therapy are also used, depending on the severity of the symptoms.

In addition to other measures, patients are advised to have strict bed rest. Severe cases may even require treatment in the intensive care unit.

 

How dangerous is TBE?

Once the infection has been overcome, late effects can occur in individual cases. Some resolve over a few weeks or months; some are permanent. These can be headaches and exhaustion, but also neurological problems such as speech disorders, concentration problems, paralysis and seizure disorders.

The average risk of death from tick-borne encephalitis is about one per cent. The risk is sometimes significantly higher if the brain, meninges, and spinal cord are affected together.

How many ticks have TBE?

Not every tick transmits the TBE virus. In addition, the risk that a tick can transmit the TBE virus is higher in certain areas than in others – these are referred to as TBE risk areas. But even there, according to the Robert Koch Institute (RKI), there are only one to fifty ticks out of a thousand.

TBE risk areas: Which areas are affected?

The RKI offers an up-to-date map of the TBE areas, broken down by district. In Germany, Bavaria Baden-Württemberg and the south of Hesse, Thuringia, and Saxony are particularly affected, as are parts of other federal states.

Other European-affected countries include Austria, Poland, Denmark, Sweden and Norway. Before you go on holiday, find out whether your travel destination is one of the risk areas.

 

How can I protect myself from TBE?

It is advisable to take appropriate tick-repellent measures to prevent disease transmission through tick bites, especially during the tick season from March to November. You can find out how to protect yourself from tick bites here.

However, the only safe protection is a TBE vaccination, colloquially known as a tick vaccination. But be careful: The vaccination only prevents tick-borne encephalitis. It is not a Lyme disease vaccination! The vaccine is ineffective against this disease, which tick bites can transmit.

Even if only a tiny proportion of ticks transmit TBE, vaccination makes sense. The disease can sometimes be fatal, and no drug can be used to treat the pathogen.

However, vaccination must be preventive: subsequent vaccination following the bite of a tick infected with a virus is ineffective.

TBE vaccination: who should be vaccinated?

The STIKO (Standing Vaccination Committee) recommends vaccination against TBE for all people who live in a risk area and are often in nature, such as people who like to spend their free time outdoors. Vaccination is generally recommended for forest workers and members of similar professions. People who work in appropriate laboratories should also be vaccinated.

For people who live in risky areas, the costs of the TBE vaccination are covered by health insurance companies. Exceptions are groups of people who need the vaccination for professional reasons. In this case, the employer bears the costs.

Vacation in the TBE risk area

Before going on holiday to a risk area, seek travel medicine advice. Vaccination is also recommended for trips with tick exposure to German or foreign TBE risk areas. If you need a vaccination for a private trip, you may have to bear the costs yourself. However, please discuss this with your health insurance company in individual cases.

 

TBE vaccination for children

Because ticks bite them very often, the TBE vaccination for children is generally recommended after individual consideration. A particular vaccine is used for them. Children can be vaccinated from the age of one.

Vaccination after surviving TBE infection

You are likely immune to the pathogen after surviving the disease. However, whether or not beauty lasts for life has yet to be sufficiently researched. Therefore, these people should also be vaccinated if they belong to the risk group.

Tick ​​vaccination during pregnancy and lactation

Beim FSME-Impfstoff handelt es sich um ein inaktiviertes Virus. Deshalb ist eine Impfung während der Schwangerschaft grundsätzlich möglich, sollte aber nur nach Nutzen-Risiko-Abwägung und sicherheitshalber erst ab dem zweiten Schwangerschaftsdrittel erfolgen. Auch in der Stillzeit kann die FSME-Impfung erfolgen.

 

Wie oft muss die FSME-Impfung erfolgen?

Um eine Grundimmunisierung zu erreichen, sind drei Impfungen notwendig. Das Impfschema ist abhängig vom verwendeten Impfstoff. In Deutschland werden die Impfstoffe FSME-Immun® und Encepur® eingesetzt.

Um den vollen Schutz zu erreichen, wird die Impfung im Abstand von mehreren Monaten wiederholt. Bei Erwachsenen ergibt sich folgender Plan für das Impfschema:

1. Die erste Dosis wird verabreicht.
2. Ein bis drei Monate später folgt die zweite Dosis.
3. Die dritte Dosis wird fünf bis zwölf (FSME-Immun®) beziehungsweise neun bis zwölf (Encepur®) Monate nach der zweiten verabreicht.

Wenn zeitnah ein Impfschutz erreicht werden soll, etwa weil kurzfristig eine Reise in ein Gebiet mit FSME-Verbreitung ansteht, können die einzelnen Dosen in kürzeren Abständen verabreicht werden.

Auffrischung: Wie lange hält die FSME-Impfung?

Die erste Auffrischung sollte nach drei Jahren erfolgen, im Anschluss daran im Rhythmus von fünf Jahren. Menschen über sechzig Jahre hingegen sollten sich weiterhin alle drei Jahre gegen FSME impfen lassen.

Wann sollte man mit der FSME-Impfung beginnen?

Grundsätzlich kann die erste Dosis der FSME-Impfung jederzeit verabreicht werden. Damit man aber bereits zu Beginn der Zeckensaison geschützt ist, ist es ratsam, die erste Spritze in den Wintermonaten zu verabreichen.

Zwei Wochen nach der zweiten Impfdosis besteht bei den meisten Menschen bereits ein vorläufiger Schutz – die langfristige Schutzwirkung wird jedoch erst durch die dritte Impfung sichergestellt.

 

FSME-Impfung: Nebenwirkungen

Alle Impfungen können lokale Impfreaktionen wie Schwellungen, Rötungen oder Schmerzen an der Einstichstelle verursachen. Das gilt auch für die FSME-Impfung.

Weitere Nebenwirkungen der Impfung, die in den ersten Tagen nach der Verabreichung auftreten können, sind diffuse Symptome wie:

• erhöhte Temperatur oder Fieber
• Kopf-, Gelenk- oder Muskelschmerzen
• Magen-Darm-Probleme
• ein allgemeines Krankheitsgefühl, Mattigkeit
• Schmerzen und Rötungen an der Einstichstelle

In den meisten Fällen klingen diese Impfreaktionen nach kurzer Zeit von selbst ab. Sehr selten treten darüber hinaus Missempfindungen wie Kribbeln oder Taubheitsgefühle auf.

In Einzelfällen kann die FSME-Impfung vor allem bei Erwachsenen Nebenwirkungen in Form von schweren und dauerhaften Schädigungen des Nervensystems zur Folge haben. Diese zeigen sich insbesondere durch Lähmungen. Das Risiko für solche Spätfolgen ist jedoch äußerst gering.

Bei einer Allergie auf Hühnereiweiß sollte die FSME-Impfung nur nach sorgfältiger Abwägung von Nutzen und Risiken erfolgen.

A passive vaccination against TBE was also available in Germany until 2003. After administration of this vaccination, there were isolated cases of severe cases of TBE. This vaccination is no longer available since the protective effect was not proven.