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It is estimated that up to one in six ticks can be infected with the tick-borne encephalitis virus (TBE), and it takes just a few minutes to become infected. TBE is a serious disease of the central nervous system that can lead to severe complications and even death. The only effective form of preventing TBE is vaccination.
Five degrees above zero
Although in Poland the “tick season” usually begins in spring and ends in late autumn, taking into account climate changes, especially warming, ticks threaten us all year round. In fact, it is enough for the temperature to rise to five degrees, and tick activity to increase and they start looking for hosts. It is worth remembering, because dangerous arachnids can be found not only in forests, but also in city parks, meadows and home gardens.
This is evidenced by the results of the study “Ticks in city parks”, carried out by the National Institute of Hygiene in Warsaw, both in the Bielany Forest and in Łazienki Królewskie, the risk of being bitten by ticks was very high. Also in Poznań: Uroczysko Golęcin and Uroczysko Malta were characterized by a very high risk. Similarly, the City Beach in Olsztyn.
Not only Lyme disease …
Why is it better not to play with the tick? Contrary to appearances, Lyme disease, of which we hear so much, is not the only threat. There are many more tick-borne diseases! One of these is tick-borne encephalitis (TBE), a disease of the central nervous system caused by the TBE virus with symptoms of meningitis, encephalitis, or both.
And although in the public consciousness KZM is wrongly perceived as a “disease of foresters”, as emphasized by prof. dr hab. med. Joanna Zajkowska from the Department of Infectious Diseases and Neuroinfections, University Teaching Hospital in Białystok, anyone can get sick. If we are exposed to a tick bite, we are also threatened by the tick-borne encephalitis virus. The risk of contracting TBE virus increases every time we go for a walk with our dog, go jogging in the morning, or go for a bike ride.
Statistics prove that TBE is an epidemiological problem with a significant impact on public health. According to data from epidemiological reports, in most countries in close proximity to Poland, the number of reported cases of TBE is higher than in previous years. This can be seen in the statistics from Germany, the Czech Republic and Slovakia. A record increase was also recorded in Switzerland, where 73 percent was confirmed. more cases of TBE infections than in 2019, and in Germany, where there were almost 60% more infections!
The Czechs, Lithuania, Latvia and Estonia have a lot of registered cases of TBE. We have fewer registered cases – about 200-300 a year, but research shows that the number is underestimated. Most are registered in Podlasie, Lublin and Lesser Poland. However, it must be remembered that the disease is recorded all over Poland – the further west of the country – the less – comments Prof. Zajkowska.
Various contamination scenarios
Experts emphasize that TBE infection may take a different course. Why some pass the infection asymptomatically and others suffer and even die from it remains a mystery. One thing is for sure: even a quick tick removal may not protect us from the disease. The TBE virus, unlike the bacteria that cause Lyme disease in the middle intestine of the tick, is found in arachnid saliva and after a few minutes it enters the human body.
The disease may be mild, but also involving the central nervous system. Its severe course is especially dangerous for children because their brain is in the process of maturation. Even minor damage to it can have huge consequences for children in the future. TBE is also particularly dangerous for the elderly and those with impaired immunity (treated for psoriasis, rheumatoid arthritis or other autoimmune diseases). They do not have the body’s defenses to stop virus replication. The course of the disease can then be dramatic. Although it must be remembered that in young, healthy people, the disease can also involve the central nervous system and paralysis, and it is really difficult for doctors to tell why this is happening – comments Prof. Zajkowska.
Serious complications of TBE are irreversible
As prof. Zajkowska, the course of TBE infection can be compared to a triangle placed with the base down – a pyramid. Its bottom is the most common situation – after entering our body, the KZM virus is eliminated at the very beginning.
Another “scenario” of infection, one floor above, is the so-called flu-like form, the first stage of the disease – viremia, fever, muscle pain. All this happens up to 28 days after the tick bite and at this stage the infection may stop.
If the disease ends in the period of flu-like symptoms, there are no further complications. The virus then does not reach the central nervous system, is eliminated in the periphery and does not cause permanent damage. If, on the other hand, our body cannot cope with the infection, then after the flu-like period there is a day, two breaks (sometimes there are no such breaks) and symptoms from the central nervous system appear – this is the next floor.
Then most often the patients have meningitis, which is manifested by high fever, severe headache, nausea, vomiting. Patients then go to the hospital. If the patient is less fortunate, the meninges and the brain become inflamed with involvement of the centers in the brain, i.e. with disturbed consciousness. There may also be inflammation of the meninges, brain and spinal cord and nerve roots – in various configurations – adds the specialist.
The most dangerous complications at the top of the pyramid are the rarest, but they always have serious consequences.
The most common complication of nerve root involvement is paralysis of the shoulder plexus. It can be unilateral or bilateral paralysis. It will manifest itself in such a way that the sick person cannot raise his hands up, that is, the mobility of the hands is kept but not the hands cannot be raised. Added to this is the so-called a symptom of a flabby neck. Paralysis can also affect the lower limbs, cranial nerves, and the respiratory center. With the latter paralysis, if the patient manages to survive, he will need constant breathing support – lists Professor Zajkowska.
Unfortunately, serious complications of TBE are irreversible. In the case of those influencing motor skills, it is only possible to improve the patient as part of rehabilitation.
Motor damage caused by complications can be reduced to some extent by rehabilitation. With a few rehabilitation cycles, limb mobility is improved, but the full fitness is not regained. Damage such as muscle atrophy cannot be “repaired” at all. Muscle mass does not rebuild, which makes the limbs weaker. It cannot be rehabilitated – points out the specialist.
Prevention instead of risk
Although modern medicine has not yet found a cure for TBE, we can protect ourselves against the disease by vaccination. The TBE vaccine is one of the best vaccines available on the medical market. Its effectiveness is up to 99%. This is evidenced by the fact that Polish foresters, who have been vaccinated regularly since 1993, do not suffer from TBE. There are no serious undesirable post-vaccination reactions among them.
Importantly, not only those who work or live in the forest should get vaccinated. As prof. Zajkowska, there are two groups of indications. The first one is determined by the region of residence and being.
Inhabitants of the eastern provinces of Poland should be vaccinated, especially those who live outside large cities – emphasizes the professor.
Our activity is also an indication for vaccination. People who go for a walk with their dog, run in a park or forest, mushroom pickers, garden owners – generally those who spend time in nature should get vaccinated. Children should also be vaccinated against TBE.
Most children are infected between the ages of 5-6. If we often go to the park with our child, spend time in nature, it is worth vaccinating the child against TBE. There is no risk associated with vaccination, and we are not able to predict the effects of the disease, especially the neurological ones – warns prof. Zajkowska.
To prevent tick bites, wear appropriate clothing, high boots and a head covering that cover the skin. When staying in forests or city parks, it is advisable to use repellants, i.e. tick repellants. After returning from walks, the skin should be carefully inspected, especially the places most often selected by ticks, such as: groin, armpits, the inside of the arms, the area behind the auricles.