The simplest surveys show that often ideas about the danger of ticks and the tick-borne encephalitis they carry are rather vague not only among school-age children, but also among adults. That is why newsletters and stands with the headings "Beware of Ticks!" actively used in clinics, kindergartens and schools.
The following will provide key information about the dangers associated with tick bites, as well as the rules of behavior in nature, the observance of which can significantly reduce the risk of attacks by these parasites and the likelihood of contracting various infections from them. Parts of this article can be used for the production of bulletins, memos, stands. On the basis of it, it is possible to conduct classes in preschool educational institutions, parent consultations and classroom hours in schools.
So, let's see what you need to know first about ticks and the dangers to humans associated with their bites ...
Caution: ticks!
Bites of ixodid ticks are one of the often underestimated dangers that a person may encounter when going out into nature, staying in the countryside, and even just while walking in the green areas of cities in the spring and summer season. With the bites of these arthropods, it is possible to infect a person with deadly infections, and the treatment of the diseases they cause is difficult and does not always end successfully.
At the same time, even with a high number on the territory, ticks are hardly noticeable, and they can wait both in the wild and in parks and courtyards within the city. Thanks to the anesthetic injected into the wound, their bites are painless, and often the parasite is found only at the stage of bloodsucking, when the infected saliva has already entered the wound.
It is important to understand that, unlike stinging insects that attack a person in self-defense, ticks attack people intentionally, since their survival and reproduction directly depend on bloodsucking. Millions of years of evolution have provided the parasite with a very efficient body structure and behavioral tactics, which together provide a high chance of finding a victim (host).
This means that in order to protect yourself from tick bites, you need not only to behave correctly in nature (this is not enough!), but also to take special measures, which we will talk about a little later.
Ticks and tick-borne encephalitis
Ticks are arthropods that belong to the class of arachnids. Today, there are more than 54 thousand species of them in the world (moreover, some experts believe that the real number of tick species, taking into account forms that have not yet been described, can be many times greater).
Different types of ticks differ significantly in lifestyle, feeding methods and habitats. Most of them are completely harmless to humans, and some are even beneficial for agriculture.
The greatest danger to humans is the so-called ixodid ticks - a relatively small group of species that are highly specialized parasites of large animals and humans. They feed on blood, and in order to saturate, grow, develop and reproduce, they must necessarily consume the blood of host animals.For this reason, the way of life, body structure and habits of ticks are maximally adapted to lie in wait for animals, attack and suck out the maximum amount of blood possible for these arthropods.
In itself, the bloodsucking of ticks, although unpleasant for humans, does not pose a significant danger. In only a small number of people, bites can cause severe allergic reactions. Those types of ticks, whose bites are extremely painful and allergenic, are not very common in Russia.
The most dangerous are infections, the pathogens of which develop in the organisms of ticks and can be transmitted to humans through a bite. Of these infections, two are the most significant:
- Tick-borne encephalitis;
- Lyme borreliosis (Lyme disease).
Both of them can lead to the death or disability of an infected and ill person if he is not provided with medical assistance in a timely manner.
In addition to these diseases, ixodid ticks also carry anaplasmosis, Marseilles fever, tularemia and some other diseases.
Tick-borne encephalitis is considered the most dangerous of the tick-borne diseases. This disease is quite difficult to treat, while due to brain damage, irreversible neurological and mental disorders are possible, and in the most severe cases, the death of a sick person.
Not every Ixodes tick is a carrier of these diseases, and not even every bite of a truly infected tick leads to the development of the disease. According to statistics, even in the most epidemiologically dangerous regions, only 6% of ticks belonging to the carrier species of encephalitis and borreliosis are infected with these infections. And out of 100 people bitten by infected parasites, only 5-6 get encephalitis or borreliosis.
On a note
These numbers seem small: in fact, out of 10,000 tick bites, only 20-25 lead to infection. However, in reality, even with such a low infectivity, ticks are dangerous because of their large number. In late spring - early summer, in the grass layer of 1 hectare of a sparse deciduous forest, there can be several million ticks of different ages, and during a normal hour-long walk, several dozen parasites can get on a person’s clothes or body. People who, for one reason or another, are constantly in nature (workers in agriculture and forestry, landscapers, fish farm workers, gardeners), are bitten regularly by ticks, and even urban residents are bitten on relatively rare trips to nature.
The greater the number of ticks at the same time started bloodsucking on a person, the higher the likelihood of infection. According to statistics, the most severe cases of tick-borne encephalitis were recorded among hunters and fishermen, from whose bodies, after leaving for nature, several dozen attached parasites were removed.
In Russia, Ukraine and Belarus, the main types of tick-borne encephalitis vectors are:
- Dog tick (Ixodes ricinus), common in the European part of Russia, Ukraine and Western Europe;
- Taiga tick (Ixodes persulcatus), living in Siberia and the Far East.
The carriage of the virus in some other species of ixodid ticks has also been registered, but their epidemiological significance is much lower.
Dog and taiga ticks are outwardly very similar, and only a specialist can identify the differences between them.
For example, the photo below shows a dog tick:
And here is the taiga tick:
Moreover, under natural conditions, it is difficult for a non-specialist to distinguish encephalitis-carrying tick species from those that do not carry the virus. Therefore, it is generally accepted that any forest tick can potentially infect a person when bitten, and the ixodid ticks themselves are often called encephalitic in everyday life, which is not entirely correct.
Where do ticks live and how do they bite?
In summer and spring, adult ixodid ticks stay on the grass, lower branches of shrubs, on the ground, waiting for a person or any large animal to appear next to them. When the parasite senses an approaching prey, it stretches its front pair of legs forward and above itself, and if a person touches a blade of grass on which the parasite is located with clothing or body, it immediately clings to clothing or skin with its paws and clings to it. Then the parasite crawls to the most suitable part of the body, bites through the skin, reaches the blood vessel with its chelicerae, pierces it and begins to suck blood.
On a note
Also, ticks can move to humans from domestic animals (for example, when milking cows) and attack from the branches of low shrubs, but this rarely happens.
The structure of the body and mouth organs of the tick is such that after the start of bloodsucking, the parasite is very securely fixed in the skin, in which its head is almost completely immersed. It is very difficult to remove it from the body - in many cases, if removed incorrectly, the body of the parasite comes off the head. If after this the head is not removed from the skin, an abscess and suppuration may develop in this place.
The tick sucks blood for a long time - from several hours if it is a small immature individual (nymph), up to 3-4 days if it is an adult individual (imago).Females feed especially for a long time, they need a large amount of food for the development of eggs. The digestive system and the body of the tick are adapted to receive a large amount of blood, and therefore, during feeding, the size of the arthropod can increase several times, and the weight - hundreds of times.
If the parasite has successfully sucked blood, it detaches from the host and falls to the ground. After that, adult females look for a secluded place under stones, in cracks in the ground, under leaf litter, where they lay from several hundred to several thousand eggs and die.
The eggs hatch into larvae, which attack mainly rodents and insectivorous mammals, and after saturation they molt into nymphs. Nymphs feed on hares, dogs, cats, hedgehogs, less often on ungulates and humans, then molt and turn into adults. At this stage, after saturation, males often mate with females directly on the body of the host, and fertilized females repeat the reproductive cycle.
The photo shows a mouse with several mites embedded in its skin:
It is adult ticks that most often attack humans. However, any individual at any stage of development can be infected with tick-borne encephalitis virus.
To move to a new stage of the life cycle, as well as for reproduction, each individual must necessarily drink blood once.
In the largest numbers, ticks inhabit meadows, vast forest glades, river valleys, pastures, including mountain pastures. Nevertheless, they are very numerous in parks (including within the boundaries of large cities), in summer cottages and in gardens, in forest belts. The higher the grass in one place or another and the less often the soil is plowed there, the more favorable the conditions for the life of ticks here.
In Russia, Ukraine, Kazakhstan and Belarus, the peak of tick activity and the largest number of their bites are recorded in May, June and July. In the southern regions, pocus can be observed already from the end of March, and in the northern regions they are recorded until August.
Where and when can you get tick-borne encephalitis?
You can become infected with tick-borne encephalitis during the season of tick activity in any epidemically dangerous region where these parasites live. A bite with transmission of infection can occur:
- In the park, in the wastelands between the houses;
- In the garden, in the garden, on the plot;
- In the forest or on the river bank;
- In a meadow, pasture during a hike or picnic;
- In a mountain valley (for example, in Altai or in the Sayan Mountains).
The main conditions for the existence and activity of ticks are the presence of grass in which they hide and from which they attack people, as well as various shelters on the ground - leaves, pieces of wood, stones, just cracks. The higher the grass in one place or another and the more shelters on the ground, the more ticks there are, as a rule, and the higher the likelihood of their attacks.
Also, the likelihood of bites is higher in the wild, where a large number of different tick hosts (rodents, insectivores and ungulates) live.
The tick-borne encephalitis virus does not pose a threat to the tick and does not kill it. Therefore, being infected at any stage of its life cycle, a tick can pose a danger to humans for the rest of its life.
The peak incidence of tick-borne encephalitis and Lyme disease coincides with the peaks of tick activity in nature. The greatest number of infections is recorded from May to July, and in warm and hot weather the parasites are most active, and bites occur most of all.
Reminder for parents
Tick-borne encephalitis can be contracted not only by a tick bite, but also by drinking fresh milk. Goats get encephalitis from ticks, and the virus particles spread throughout their bodies and enter their milk. The use of such milk in food without heat treatment can cause infection. Cows, unlike goats, do not suffer from encephalitis, but the virus can also enter their milk from biting ticks.
Geography of distribution of tick-borne encephalitis: the most dangerous regions
Tick-borne encephalitis is registered in the middle zone of Eurasia and in some states of Australia.
The area of distribution of the disease in Eurasia runs in a narrow strip from the North Sea in the west to the Sea of Okhotsk in the east. Its foci and individual cases of infection are known in the Netherlands, Finland, Germany, Ireland, Poland, the Czech Republic, Latvia, Lithuania, Estonia, Yugoslavia. The disease is widespread throughout Ukraine and Belarus, but in Ukraine more or less constant outbreaks are recorded only in Transcarpathia.
In Russia, the disease is recorded throughout the European part south of Karelia, in the Urals and in southern Siberia. The band of distribution of tick-borne encephalitis stretches across the country and reaches the Far East, capturing the northern regions of Kazakhstan, Mongolia and China. Isolated cases of infection were noted in Kyrgyzstan.
Of the regions of Russia, the most severe epidemiological situation is noted in the Sverdlovsk, Tomsk, Irkutsk and Omsk regions, the republics of Khakassia, Tuva and Buryatia, in the Krasnoyarsk Territory. The largest number of cases of bites and infections transmitted by ixodid ticks is recorded here.At the same time, in the Far East, the maximum level of lethality of the disease is noted with an overall lower infection rate.
What to do after a tick bite?
In most cases, tick bites are noticed at the stage when the parasite has already attached itself to the skin. The tick sucks blood for a very long time, and therefore it is difficult not to notice it on the body (although this also happens - on various trips and expeditions, when people do not undress and do not swim for a long time). If the body is examined at least once a day, all sucking bloodsuckers can be detected.
If a tick is found on the skin, it should be removed as soon as possible. If he has not yet stuck, then just shake it off, and if he has already stuck, then you need to remove it from the skin. This can be done in several ways:
- Take out with the help of a special extractor - a tool in the form of a spatula with a groove, with which the tick is captured at the point of contact with the skin and removed with a gentle movement;
- Remove with thread. A tightening loop is made on it in the middle, it pounces on the parasite and tightens at the point of contact with the skin. Then, with gentle movements to the sides, the body of the tick loosens in the wound and gradually stretches out;
- Take out with fingers. In this case, the tick is captured by the body and rotates in the wound. At the same time, its proboscis ceases to be retained in the tissues and the parasite is easily removed.
After removing the tick, the wound must be treated with any antiseptic: alcohol solution of iodine, hydrogen peroxide, medical alcohol.
If, for one reason or another, the head of the parasite remains in the wound, you should try to remove it, just as a splinter is removed.If this was not possible, then it is advisable to see a doctor who can remove the remnants from the skin and properly treat the wound.
It is advisable to save the removed tick and submit it to the laboratory for research within 24 hours. The analysis will accurately determine whether the tick was infected with the tick-borne encephalitis virus or Borrelia.
On a note
Laboratories in which relevant research is carried out operate at sanitary and epidemiological stations, hospitals and clinics in all major cities. The address of the nearest point where you can take a tick for analysis can be found by calling the department of Rospotrebnadzor in a particular area.
If tests show that the parasite is infected with the tick-borne encephalitis virus, the affected person must be taken to a medical facility. Here he will undergo emergency prophylaxis, which consists in the introduction of an immunoglobulin preparation into the body. This tool blocks the further development of the infection and prevents the disease.
Important!
Specific prevention measures are effective only during the first 4 days after the bite, but in the best case, the victim needs to be given immunoglobulin in the first two days.
If it is not possible to deliver the bitten person to a hospital or clinic, it is necessary to remember exactly (or rather write down) the date of the bite. In the future, when the first signs of the disease appear, the victim should be taken to a medical facility as soon as possible, and the doctor should be informed of the date of the bite. This will help you take the most effective treatment measures.
Emergency prophylaxis of Lyme borreliosis is not required, since this disease is relatively easy to treat, and when the first symptoms appear, it is quickly treated.
Signs of infection with tick-borne encephalitis and other tick-borne infections
After a tick bite, it is necessary to carefully monitor the condition of the bitten person for at least a month, and if he shows signs of tick-borne infections, promptly deliver him to the hospital.
The incubation period of tick-borne encephalitis and Lyme borreliosis lasts 7-14 days, but in Lyme disease it can be much longer in some cases - up to a year or more.
The main symptoms of tick-borne encephalitis:
- Typical fever with fever, malaise, nausea, pain in the head and muscles;
- Violation of coordination of movements;
- Fainting, dizziness;
- Neck stiffness.
Similar symptoms develop in Lyme disease, but the most unambiguous sign of it is the so-called migrating erythema: a large red spot at the site of the bite, surrounded by a distinctly separated ring. At the site of erythema, many patients experience pain, itching, or burning.
Also, with Lyme disease, allergic reactions are pronounced: a rash on the skin, a flu-like syndrome.
Any of these signs are highly likely to indicate the onset of the disease. The sooner treatment is started, the higher the chance of a successful outcome.
Treatment in case of infection
Treatment of tick-borne encephalitis is a significant difficulty due to the lack of funds that allow you to quickly eliminate the viral infection in the body. In medical practice, immunoglobulin preparations are used, but at the stage of acute manifestation of symptoms, these drugs are already ineffective.
High doses of interferons used for intravenous infusions can have a positive effect, but do not guarantee the destruction of the pathogen, but only provide some protection for cells that have not yet been affected.For this reason, even in a clinical setting, the probability of curing the disease is not absolute.
Important!
The later and the more severe the patient is delivered to the clinic, the higher the likelihood of developing irreversible mental disorders and death.
Treatment of tick-borne encephalitis involves strict bed rest with limited motor activity, parallel symptomatic therapy to normalize the patient's condition, and taking antihistamines in case of allergy.
Lyme disease is also treated in a hospital, but with antibiotics. Its causative agent is sensitive to tetracyclines, penicillins, cephalosporins, so the doctor's choice is quite wide. If there is a risk of complications in the joints, heart or nervous system, long courses of bicillins are carried out.
Lyme disease can become chronic with ineffective treatment. In this case, the disease is often complicated by arthritis, osteoporosis and other joint disorders.
Ways to prevent tick bites and infection with tick-borne encephalitis
Competent behavior in nature and the observance of simple rules can reliably protect against tick bites.
In particular, in the second half of spring and in the first half of summer after being in nature, especially in places with uncut grass, it is necessary to conduct a mutual examination of the body. The adults examine the children and then each other, with particular attention to the legs, back, buttocks, groin, armpits, scalp borders, and behind the ears. When detected, ticks are shaken off or removed from the skin.
Such inspections are preferably carried out every 1-2 hours. In this case, ticks can be detected immediately after they hit the body, even before suction.
In places where signs “Attention, ticks!”, Or similar, are installed, it is better not to walk unnecessarily, and after a walk it is necessary to inspect the body.
In regions with a high risk of infection with tick-borne encephalitis, additional measures are required:
- You need to go out into nature in special clothes. Pants must be tucked into socks, or they must have elastic bands that tightly cover the leg. Underwear, shirt or jacket should be tucked into pants, there should also be elastic bands on the sleeves, under which the tick will not crawl. If you plan to stay in a forest with a lot of bushes, it is desirable that there is a hood on the jacket or jacket. All these measures will reduce the likelihood of a tick penetrating the skin;
- Clothing for going out into nature should be light-colored so that the parasite can be easily detected on it;
- Clothing or the body must be treated with repellents, preferably based on DEET - they are a reliable protection against ticks and other blood-sucking parasites.
Directly in nature, you should stay away from tall grass and shrubs.
In the most epidemiologically dangerous regions, it is advisable to make an anti-encephalitis vaccination, which will provide reliable protection against the disease even with a bite.
Prevention measures also include informing the population about the rules of behavior in nature and the prevention of tick bites. For this purpose it is useful:
- Conduct class hours and talks in schools on the topic of the correct behavior of schoolchildren in nature;
- Consult parents in preschools and schools about precautions to protect against tick-borne encephalitis;
- Produce noticeable and attention-grabbing sanitary bulletins, stands, posters, leaflets, booklets, folders with drawings and photographs that are hung or distributed in clinics, hospitals, schools and kindergartens, at the entrances of houses;
- Conduct briefings for educators in kindergartens and teachers in schools resting in various sanatoriums, prepare orders in advance for such briefings;
- At the beginning of the tick season, or before it, issue advisory articles in newspapers and reports on local television channels with warnings about the dangers of bites and recommendations on how to avoid them;
- Make notifications in schools about the need for vaccination of students and their parents in epidemiologically dangerous regions;
- Involve students in educational work - develop information stands and make warning signs, conduct thematic biology lessons with a demonstration of live ticks.
The picture below shows a variant of the information stand on the topic of tick-borne encephalitis:
The main responsibility for compliance with the rules of protection against tick bites and the prevention of tick-borne infections in children lies with the parents. Measures to protect yourself from infection are not officially mandatory even in the most dangerous regions. But on how diligently and to what extent both adults and children will observe these measures, their safety in nature and the likelihood of a successful outcome when bitten by a parasite depend.
Be careful in nature, beware of ticks and help protect your loved ones from them!
Useful video about the danger of ticks for humans
How to 99% protect yourself from tick bites in the forest
