Tick-borne Encephalitis (TBE) is a disease caused by a virus transmitted by tick bites. You will also get Tick-borne Encephalitis by eating or consuming unpasteurized milk items (such as milk and cheese) from tainted goats, sheep or cows.
Tick-borne Encephalitis (TBE) is a bacterial infectious disease of the central nervous system. The condition is most often manifested as meningitis, encephalitis, or meningoencephalitis. Long-lasting or lifelong neuropsychiatric effects are observed in 10% to 20% of contaminated patients.
The number of recorded cases has risen in most countries. Tick-borne Encephalitis (TBE) presents a significant health threat to Europe as the number of reported human cases of Tick-borne Encephalitis (TBE) in all endemic areas of Europe has risen by almost 400 per cent over the last three decades.
The tick-borne encephalitis virus is known to infect a wide variety of hosts, including ruminants, insects, rats, carnivores, horses and humans. The disease may also transmit from animals to humans, with ruminants and dogs being the primary source of human infection.
As of 2011, the disease has been the most widespread in Central and Eastern Europe and Northern Asia. Approximately ten to twelve thousand cases are reported annually, but the rates vary greatly from one area to another.
Most of the fluctuations are due to variations in the host population, notably in the case of deer. In Austria, the comprehensive free vaccine policy since the 1960s decreased the occurrence by about 85 per cent in 2013.
In Germany, there were at least 95 cases (2012) and a maximum of 584 cases (2018) of Tick-borne Encephalitis (or FSME as it is called in German) in the 2010s. More than half of the confirmed cases in 2019 have meningitis, encephalitis or myelitis.
The risk of infection has been shown to increase with age, particularly in people over 40 years of age and has been higher in men than in women.
The majority of cases were in Bavaria (46 per cent) and Baden-Württemberg (37 per cent), even fewer in Saxony, Hesse, Niedersachsen and other states.
A total of 164 Landkreises are declared FSME-risk zones, covering all of Baden-Württemberg except the City of Heilbronn.
In Sweden, the majority of cases of Tick-borne Encephalitis (TBE) occur in a band running from Stockholm to the west, especially around lakes and the surrounding Baltic Sea region.
This represents the broader population engaged in outdoor activities in these regions. Overall, the projected probability for Europe is approximately 1 case per 10,000 human-months of forest activity.
While in certain areas of Russia and Slovenia, the incidence of cases can be as high as 70 cases per 100,000 people per year.
Travellers to infectious areas do not always become cases, with just 5 cases recorded among U.S. travellers returning from Eurasia between 2000 and 2011 at a pace as low as that of 2016 in the U.S.
Centers for Disease Control and Prevention recommended vaccine only for people who are widely infected in high-risk areas.
Table of Contents
- Symptoms of the Tick-borne Encephalitis (TBE)
- Cause of Tick-borne Encephalitis (TBE)
- Transmission of Tick-borne Encephalitis (TBE)
- Diagnosis of Tick-borne Encephalitis (TBE)
- Treatment of Tick-borne Encephalitis (TBE)
- Who’s at risk of Tick-borne Encephalitis (TBE)?
- What will travellers do to avoid Tick-borne Encephalitis (TBE) from happening?
- Prevent tick bites
Symptoms of the Tick-borne Encephalitis (TBE)
Any of the pathogens remain asymptomatic. In case of clinical disease, the incubation time for Tick-borne Encephalitis (TBE) lasts 2–28 days (most typically 7–14 days) accompanied by 1–8 days of general cold symptoms, such as weakness, headache and general malaise, generally associated with a fever ≥38 ° C.
During an asymptomatic period of 1–20 days, up to 15 % of patients undergo a second phase of the illness marked by fever sometimes reaching 40 ° C and symptoms of central nervous system involvement, such as meningitis (e.g. temperature, fatigue and stiff neck), encephalitis (e.g. somnolence, agitation and sensory disturbances), myelitis or radiculitis.
Encephalitis that occurs during this second phase can result in paralysis, permanent sequelae, or death.
Approximately 1% of cases with neurological pathologies may die; higher fatality rates have been recorded by the Russian Federation and may be due to a particular subtype of the virus.
The seriousness of disease rises with the age of the patient, but deaths have been reported in all age ranges. There is no particular remedy for Tick-borne Encephalitis (TBE).
Cause of Tick-borne Encephalitis (TBE)
Tick-borne Encephalitis (TBE) is caused by the tick-borne encephalitis virus, a member of the Flavivirus family.
It was isolated for the first time in 1937. There are also three subtypes of viruses: European or western tick-borne encephalitis virus (transmitted by Ixodes ricinus), Siberian tick-borne encephalitis virus (transmitted by I. persulcatus) and Far-Eastern tick-borne encephalitis virus, formerly known as Russian spring-summer encephalitis virus (transmitted by I. persulcatus).
Every year, Russia and Europe record 5,000–7,000 human cases.
Study on tick-borne infections, includingTick-borne Encephalitis (TBE), was performed by the former Soviet Union.
Transmission of Tick-borne Encephalitis (TBE)
Sheep ticks (Ixodes ricinus), such as this engorged female, spread the disease. It is spread by the bite of many species of infected forest ticks, including Ixodes scapularis, I. Ricinus and I are. Persulcatus or (rarely) by unpasteurized milk from contaminated cows.
Infection by goat milk eaten as raw milk or raw cheese (Frischkäse) was recorded in the German state of Baden-Württemberg in 2016 and 2017. None of the affected patients had a psychiatric condition.
Diagnosis of Tick-borne Encephalitis (TBE)
Detection of particular IgM and IgG antibodies in sera patients combined with traditional clinical symptoms are the primary method of diagnosis. Checking for the presence of antibodies in cerebrospinal fluid can be appropriate in more complex cases, e.g. during vaccination.
The PCR (Polymerase Chain Reaction) procedure is seldom used, since the tick-borne encephalitis RNA virus is most likely not present in sera or cerebrospinal fluid patients at the time of clinical symptoms.
Treatment of Tick-borne Encephalitis (TBE)
There is no clear antiviral medication for Tick-borne Encephalitis (TBE). A symptomatic brain injury requires hospitalization and compassionate treatment depending on the severity of the syndrome.
Anti-inflammatory medications, such as corticosteroids, can be regarded as symptomatic treatment under particular conditions. Tracheal intubation and respiratory assistance may be needed.
Who’s at risk of Tick-borne Encephalitis (TBE)?
Tick-borne encephalitis is found in many parts of Europe and Asia (from eastern France to northern Japan, from northern Russia to Albania).
Several thousand cases are reported per year, but there are undoubtedly several more cases that are not reported. The largest number of cases is occurring in Russia.
Other countries at high risk of disease include the Czech Republic, Estonia, Germany, Hungary, Latvia, Lithuania, Poland, Slovenia, Sweden, Switzerland, China, Japan, Mongolia and South Korea.
Travellers are most likely to get Tick-borne Encephalitis from April to November (mostly early and late summer) and when going to forested areas where ticks are abundant.
What will travellers do to avoid Tick-borne Encephalitis (TBE) from happening?
There is no Tick-borne Encephalitis-preventing vaccine available in the United States, but available in several other nations. Travellers expecting high-risk behaviours may suggest being vaccinated in Canada or in Europe.
High-risk activities include working or hiking in forested areas or woodland, adventure travel, or staying in countries where tick-borne encephalitis has been around for an extended period of time.
Travellers should take the following precautions to avoid tick-borne encephalitis:
Eat only pasteurized milk items (such as cheese and milk).
Prevent tick bites
- Cover exposed skin by wearing long pants, hats and long-sleeved.
- Tuck in your shirts, tuck pants into socks and wear protective shoes instead of sandals to prevent tick bites.
- Do not go to wooded and brushy areas with high grass, brush, and leaves. Walk in the centre of hiking trails.
- Use a repellent that contains at least 20% or more DEET for protection of several hours.
- Products containing DEET include Ultrathon, Off!, Cutter, and Sawyer.
- Always follow product directions and use as directed.
- If you are also using sunscreen, then apply sunscreen first, and insect repellent last.
- Do not ignore package directions when applying repellent on children. Do not apply repellent to their mouths, hands, and eyes.
- Use permethrin-treated clothing and gear (such as socks, tent boots, and pants). You can treat them by yourself or buy pre-treated clothing and gear.
- Treated clothing remains protective after several washings. See the product information to discover how long the protection will last.
- If treating items by yourself, follow the product guidelines carefully.
- Do not use permethrin on the skin directly.
Find and remove ticks from your body
- Bathe or shower as soon as possible after coming indoors.
- Check your entire body (under your arms, in and around your ears, in your belly button, behind your knees, between your legs, around your waist, and especially in your hair). Use a hand-held or full-length mirror to view all parts of your body.
- Be sure to remove ticks properly.
- Parents should check their children for ticks.
- Check your pets and belongings. Ticks can be on outdoor equipment and clothes.
If you feel sick and think you may have Tick-borne Encephalitis (TBE)
- Talk to your doctor or nurse if you feel seriously ill, especially if you have a fever.
- Tell them about your trip.