Where are the dangerous ticks. Tick ​​- description, species, where they live, what they eat, photo

Many modern people living in cities do not even know where ticks live, believing that forests, parks and just areas with tall grass do not pose a danger. However, as practice shows, ignorance of the dangers of a particular area can have an extremely negative impact on health, because some varieties of ticks are carriers of dangerous diseases that can not only cause disability, but also lead to death.

natural habitat

Ixodid ticks go through several stages of development throughout their lives. The size of an adult female, as a rule, is about 3-4 mm, while males rarely exceed 2.5 mm. It is worth noting that in the process of feeding, females can reach about 10 mm. Ticks on the way to adult life go through several stages of development. After hatching from the egg, the larva begins to wait for its prey, which usually becomes a small rodent or other arthropod.

A well-fed larva after feeding falls to the ground and transforms into a nymph. In the future, the nymph undergoes several molts and becomes an adult. Usually ticks feed only 1 time per developmental stage, but at the same time this process may continue long time. In the vast majority of cases, the female ixodid tick immediately after feeding begins to search for a suitable partner and then lays about 17 thousand eggs in the ground, which later become larvae. Reproduction of ticks is possible only with an abundance of food, that is, when the female accumulates a sufficient supply nutrients for egg production.

Despite the popular belief that ticks only live where there are trees, this is not entirely true. The area of ​​distribution of varieties of ticks that can attack humans extends almost throughout Russia and the CIS countries, and in addition, these dangerous insects are common in northern China and in some European countries, including they are found in the Baltic States, Scandinavia, France, Austria , Poland and the Czech Republic.

Where are the pests hiding?

The larvae usually occupy a position on the blades of grass, located approximately 10-15 cm above the ground, where they wait for the passing rodents.

Nymphs can climb large blades of grass. Adult ticks occupy not only tall grass, but also shrubs no more than 1.5 m high. At each stage of its life, the tick feeds only 1 time. Usually, ticks get on their prey only when an animal or person hooks on a blade of grass or a branch on which the tick sits. At this moment, the tick begins to cling to its prey with claws and suckers, and then continues to travel through the body of an animal or person to identify suitable place for a bite.

If the fall on the prey was unsuccessful, the tick again climbs onto a nearby blade of grass or bush and continues to patiently wait for a new victim, which will be nearby and accidentally knock it onto its clothes or wool. Ticks are whimsical to weather conditions. These creatures wake up during the period when the air temperature at night warms up from +5 to +7°C. Peak activity of ticks in different climatic zones falls in April-June. At this time, ticks try to find their prey and bite. However, with the onset of the summer heat, ticks hide. The second burst of tick activity, as a rule, occurs at the end of August - beginning of September, when the first warm autumn rains create a favorable humid environment.

What is dangerous infection for humans?

• tick-borne encephalitis;
• Lyme disease;
• relapsing fever;
• spotted fever;
• Crimean hemorrhagic fever;
• babesiosis.

This is far from full list diseases that can develop after a tick bite. Some diseases that develop as a result of tick bites can be vaccinated, for example, against tick-borne encephalitis. If after a tick bite there are signs of a general deterioration in health, you should immediately consult a doctor. Only timely assistance after a tick bite can reduce the risk of developing diseases that can provoke serious complications.

Preventive actions

Despite the fact that ticks are small and it is very difficult to notice them sitting on the grass, certain precautions can be taken to avoid bites. If you plan to visit places where tick inactivity is possible, you must use special means protection from them. The most convenient are sprays,. Such sprays need to be sprayed not only open areas bodies, but also clothes and shoes.

In addition, it is very important to wear clothing for a walk in the forest that would prevent ticks from accessing the body. If the trousers that you plan to wear do not have elastic bands, the legs must be tucked into socks. It is advisable to cover the head with a headdress. In addition, it is advisable to wear a trowel with elasticated sleeves and a turtleneck under it, as the neck will protect the body from ticks.

To avoid a dangerous disease, you need to know where it lives Tick-borne Encephalitis and what are the consequences of his bite.

Encephalitis is a disease of the central nervous system that has a viral nature. The infection is transmitted by an infected tick at the time of the bite.

History of Encephalitis Infection Research

In 1935, the People's Commissariat of Health of the USSR sent a scientific expedition to the Far East. The reason was outbreaks of an unknown disease in the taiga regions. The disease arose suddenly, proceeded hard, the brain was affected. Mortality was high. Local residents got sick less often than visitors. The development of the Far East was complicated.

A.G. Panov, a military doctor, a neuropathologist, having studied the clinic, at first mistakenly mistook this disease for Japanese encephalitis. The mistake was that they get Japanese encephalitis from mosquitoes. The seasonality of the disease, its prevalence in forest areas was noted.

A year later, an expedition led by Professor L.A. was sent to the infected area. Zilber, head of the recently established virological laboratory in Moscow.

Overcoming the hard natural conditions, exposed to the risk of laboratory contamination, by mid-August 1937, members of the expedition had studied a new infectious disease. It turned out the following:

1. 1 Tick-borne encephalitis belongs to a natural focal infection.
2. 2 The infection enters the bloodstream with a bite, which is found in taiga regions.
3. 3 The clinical picture of the disease is described - symptoms and general pathological processes.
4. 4 The therapeutic effect of immune sera has been experimentally proven.
5. 5 Hares, mice, chipmunks and other forest rodents serve as natural reservoirs of the encephalitis pathogen. In the bodies of animals, the virus lives and persists. Encephalitis mites bite the animal and suck up the virus, which spreads to all organs of insects.

During the period of intensive work on a false denunciation, Professor L.A. was arrested. Zilber with his associates. They were accused of spreading Japanese encephalitis in the Far East. Further work was carried out under the guidance of Academician E.N. Pavlovsky.

Encephalitis mites are found in areas with a humidity level of 80% or more. Deciduous and mixed forests are the most suitable place. In Europe in last years they perfectly took root in city parks, forest parks, garden plots. There are known episodes of infection in the highlands and northern regions.

On the territory of Russia, the main carriers are 2 types of ticks - the dog or forest tick and the taiga tick. You can meet the taiga tick in the forests of Siberia and the Far East. to the Urals and Western Siberia accounts for 80% of the total number of cases throughout Russia. Canine encephalitic tick is common in the European part of Russia and the countries of Central and Northern Europe. In the Leningrad region, cases of the disease from bites of both species are known.

There are 2 types of foci of infection:

• natural - infection occurs in uninhabited and underdeveloped forest areas;
• anthropurgic - associated with human life.

Until the 50s of the last century, the disease was classified as professional, since it was mainly people whose production activities were connected with the forest that got sick.

At present, the frequency of infection among citizens and villagers almost the same.

The optimal habitat is grass cover near the ground. These are the edges of the forest, meadows and glades, the banks of rivers and lakes, overgrown with tall grass and shrubs. They do not live in wetlands. Dry pine forests are not a suitable place for them. The presence in the forest of animals whose blood serves as a source of food is a prerequisite.

The greatest concentration of insects is near the forest paths. With the onset of cold weather, when the temperature drops from 5˚C, insects fall into suspended animation and hibernate, burrowing into foliage or moss.

Ticks feel comfortable in major cities. Thickets of grass in the park or on garden plot, blockages of debris and branches attract mouse-like rodents, and after them, ticks.

Ticks sit on grass or shrubs at a height of up to 1.5 m. It crawls onto the human body from below. The insect reacts to the approach of a person at a distance of 5-10 m.

To avoid infection, do the following:

• get a prophylactic vaccination in the clinic;
• regularly cut the grass on city and country lawns;
• avoid dumps of branches and cut grass, as well as take measures to destroy infected insects and rodents;
• in places of suspected infection, wear anti-encephalitis clothing;
• returning from a forest or a park, examine the most vulnerable parts of the body - the neck, armpits, inguinal region;
• pets also need to be vaccinated and regularly examined upon returning from a walk.

Infection with tick-borne encephalitis occurs in the first minutes of suction.

Causes and consequences of the disease

The virus is able to survive low temperatures. When the temperature rises to 100 ˚C, it dies within 2 minutes. People, dogs, monkeys, goats get sick.

You can become infected in the following cases:

• In 80% of cases - as a result of a tick bite;
• when drinking raw milk from infected goats;
• infection in laboratory tests.

Residents of cities and visitors are the most vulnerable.

Outbreaks of spring-summer encephalitis occur at the end of May-beginning of June. The forest tick, unlike the taiga tick, has 2 active peaks - spring-summer and summer-autumn. Having penetrated into the blood, the virus enters the central nervous system. 2 days after the bite is found in the brain tissue. After 4 days, a peak of its concentration is observed.

As a result of a bite, the incubation period (the time from infection to the appearance of the first signs of the disease) is 7-21 days. With laboratory infection or through milk, the incubation period lasts up to 7 days.

The severity of the disease depends on the following factors:

• the body's ability to exhibit protective and immunological properties;
• virulence (degree of pathogenicity) of the virus;
• the number of bites - single bites are less dangerous;
• geography - tick-borne encephalitis in the western regions of Russia and in countries of Eastern Europe flows more easily than Far East and in Siberia.

If the bitten person has been vaccinated, the virus binds and the disease stops. The virus lives in females, males, nymphs and larvae. The tick transmits the virus to its offspring.

Invasion is observed in 70 regions of the country every year dangerous insects.

Experts call the three most dangerous diseases that can be obtained after a tick bite - tick-borne encephalitis, ixodic borreliosis and Crimean hemorrhagic fever. The consequences of these infections are especially terrible. How to protect yourself from infectious insects during their greatest activity?

First casualties

Warm spring days are not only the time for nature walks, barbecues and the beginning of the summer season, but also the period of the greatest activity of dangerous insects. It usually lasts until the end of summer, but the peak is in April-June. The year before last, in many regions there was simply an abnormal invasion of ticks. This was facilitated by a rather warm and little snowy winter.

Spring also turned out to be favorable, there was a lot of greenery and sunny days. What all living things need. So, going out of town, to the country or to the park, you need to remember the simplest security measures.

Every year, epidemiologists in most regions of the country, long before the onset of spring, begin to warn of the need to be vaccinated against tick-borne encephalitis. They have been preparing for the dangerous spring-summer season since autumn. Unfortunately, not all tick-borne diseases can be vaccinated.

From iscode tick-borne borreliosis(ICB) and Crimean hemorrhagic fever (CHF) vaccines have not yet been invented, and it is very easy to catch this infection. Judge for yourself, after the May holidays, according to Rospotrebnadzor, 39,165 people from 70 regions turned to hospitals in the country after being bitten by ticks, including 11,320 children.

And each region has its own danger. Tick-borne encephalitis can be caught in almost the entire territory of the Crimea, in Siberia, in the North-Western District, St. Petersburg and Karelia, the Volga region, and many areas of the Central District. In the Moscow region and Moscow, as well as in Krasnodar Territory tick-borne borreliosis is more terrible. In other southern regions - in Rostov region, Volgograd, in the Caucasus, you can catch hemorrhagic fever. So, choosing to summer rest, this must also be taken into account.

For example, for the May holidays of 2016, the most more number bitten by ticks recorded in the Sverdlovsk, Kemerovo, Irkutsk, Tyumen, Irkutsk, Tomsk, Vologda, Leningrad regions, Krasnoyarsk, Altai and Primorsky territories.

11 cases of tick-borne encephalitis were registered in the Pskov, Irkutsk, Novgorod regions, the Krasnoyarsk Territory, the Republic of Khakassia and 11 cases of Crimean hemarrhoidal fever in the Rostov region. There are two deaths. Most were infected with tick-borne borreliosis. 84 cases of ITB were registered - in Kaliningrad, Moscow, Lipetsk, Belgorod, Kaluga, Vologda, Samara, Sverdlovsk, Irkutsk Tyumen regions, in Udmurtia, the republics of Tatarstan, Tyva, Krasnodar and Zabaikalsky territories and St. Petersburg.

According to experts, despite the fact that in Moscow and the Moscow region, St. Petersburg and other large cities, forest park areas are annually treated with acaricidal preparations, it is still impossible to secure all green areas. According to the Office of Rospotrebnadzor for the city of Moscow, last year borreliosis ticks were found in some of the most crowded parks: in Kuzminki, Serebryany Bor, on Losiny Island, in Izmailovsky, Krylatsky, in the forest area of ​​Zelenograd and even Yekaterininsky.

After the May holidays before last year, 1,296 people with tick bites have already applied to medical organizations in Moscow, 234 of them are children. In the laboratory of the Center for Hygiene and Epidemiology FBUZ, specialists examined 296 ticks and 21 of them turned out to be infected with tick-borne borreliosis. According to the statistics of experts, usually the total number of insects is from 10 to 20% infected with borrels. But tick-borne encephalitis in the Moscow region can only be caught in the Taldom and Dmitrovsky districts, as well as in neighboring regions - Tver, Ivanovo, Kostroma.

How to defend yourself

Specialists of the Ministry of Emergency Situations and Rospotrebnazor advise everyone who goes to the country or to nature in May days to observe the most elementary safety rules. First, treat clothes and all equipment with modern acaricidal and acaricidal-repellent agents. You can find their names on the special site Encephalit.ru. Remember that repellents only repel ticks, while acaricides kill them. People who are allergic to various chemicals must be handled with the utmost care. But without it, you will be much worse off.

For Muscovites, this is especially true, because in the capital itself and the Moscow region there is the peak of activity ixodid ticks, which are the main carriers of tick-borne encephalitis and tick-borne borreliosis, which is also called Lyme disease. All outings must be carefully prepared.

Ixodid ticks (Ixodidae) are one of the most famous families of the subclass Ticks (Acari). They are found on all continents and live within almost all distinguished natural and climatic zones. Ixodids live even outside the Arctic Circle, which indicates their high adaptability and ability to survive in extreme conditions.

Greatest species diversity ticks are characteristic, first of all, of the forests of the tropics and subtropics (due to the relatively high level humidity, complex longline composition of vegetation and richness of possible hosts).

We will talk further about exactly where and in what months of the year the risk of meeting ticks is greatest ...

Where are ixodid ticks found?

Ticks concentrate where there are the necessary microclimatic indicators and where their potential hosts live. Within the main natural zones, these bloodsuckers are distributed in a mosaic pattern, and can often form massive concentrations of numbers.

At the same time, it should be borne in mind that ticks migrate insignificantly in the horizontal direction - they take a wait-and-see attitude, and resort to active pursuit only in exceptional cases.

Below in the photo, ticks are clearly visible in a bird around the eyes:

Thus, the main habitats of ticks are:

• forest trails;
• well-heated and moist forest edges and forest clearings;
• pastures;
• parks and squares in cities, lawns;
• kitchen gardens, gardens in the country, which are often visited by pets and people.

Therefore, this group of species has developed special adaptations to counteract the harmful effects of environment. These resistances are expressed in the choice of habitats, and here two groups of ticks are distinguished:

• pasture bloodsuckers;
• burrow bloodsuckers.

Pasture and burrow bloodsuckers

In search of better microclimatic conditions, some species of ticks took a simplified path and settled in the burrows of their hosts, where it is always warm enough, humid and there is food. Other species have adapted to life in forests and open spaces.

On a note

On a note

With a lack of water in the body, ticks descend on wet substrates and absorb moisture throughout the body.

It is a common misconception that ticks fall from trees and shrubs. In reality, they do not climb trees, but are exclusively in the grassy layer. Therefore, it is juicy, tall grass in places of frequent movement of animals and people that poses the greatest danger.

As for burrow mites, they live almost exclusively in the burrows and nests of their owners, and for this reason they usually do not pose a danger to humans. These include, first of all, Argas ticks, less often similar species are also found among Ixodids.

The life cycles of ticks are quite complex, which is associated with the peculiarities of metamorphosis and the need to search for and change hosts. At the same time, the vital activity of the same species differs significantly within different natural zones, and directly depends on the microclimatic indicators of habitats. The rhythms of life cycles are entirely dependent on the seasonal dynamics of abiotic factors, such as daylight hours, humidity, temperature, etc.

On a note

The most primitive are continuous cycles, in which synchronization with seasonal rhythms is minimized. This type of ontogenesis is characteristic of species living in a warm and humid tropical climate or in the burrows of animals and birds, where fluctuations in microclimatic parameters are insignificant.

The most complex cycles are characteristic of ticks, which need special adaptations in order to survive favorable conditions environment (primarily winter temperatures).

The longest and most complex cycles of development are characteristic of the European taiga and forest tick, whose ranges have shifted far to the north, much further than the ranges of other species. Normally, for the full development of each stage of ontogenesis, it takes about 1 year, so the minimum period of development from an egg to an adult is 3 years, and the maximum is 6 years.

Imagoes, mostly adult and hungry females, attack large mammals and humans in April-May, and the peak of aggressiveness falls on the second decade of May. At this time, they are waiting for their prey in tall grass in pastures, near ponds, forest paths, in parks and squares in cities.

On a note

Often, the eggs are attached to grassy vegetation, less often the female lays them directly on the fur of animals - then the hatched larvae will not need to look for a host.

The eggs laid in summer hatch into larvae that feed on small rodents and birds. They are tiny and have only 3 pairs of limbs, so they are sometimes confused with insects.

The photo below shows the larvae of the tick:

After feeding, the larvae look for a place for wintering: they mainly choose leaf litter and depressions in the bark of trees. There, in a state of diapause, small bloodsuckers wait out the winter. If the larva does not have time to feed before the onset of cold weather, it dies.

Sometimes the larvae have time to molt into nymphs before winter, but often molting also occurs only after leaving diapause. Each molt is accompanied by bloodsucking.

Tick ​​nymphs differ from larvae in their larger size and the presence of another (fourth) pair of legs. They are able to feed on larger animals such as dogs, cats, foxes, hares.

In the spring and summer-autumn period of the 3rd year from the beginning life cycle adults appear. They begin to feed immediately, or again go into diapause. Feeding is necessary for the female primarily for the maturation of eggs, so it is imperative that mating occurs before feeding. Males either do not feed at all, or feed for a very short time, since they perform only the function of inseminators.

The most common and massive in Russia and the CIS countries, common forest (dog) and taiga ticks carry a number of pathogens of extremely dangerous human diseases, such as:

• different forms of tick-borne encephalitis;
• tick-borne typhus;
• Lyme disease (borreliosis);
• tularemia and some others.

On a note

The tick infects its host already during suction, when it injects saliva containing pathogens of a particular infection under the skin. Moreover, the longer the tick is on the body, the more likely it is to get sick.

Symptoms of the disease do not appear immediately: the incubation period can last up to one month. In the case of tick-borne encephalitis, the development of the disease can proceed in different ways, but there are also common symptoms: more often there is a sharp increase in temperature, muscle and headaches. In case of tick-borne borreliosis hallmark infection is the appearance of the so-called migrating annular erythema - on the skin near the wound left after a tick bite, concentric rings of reddish, brown or yellow color(an example is shown below).

Prevention measures: how to protect yourself from the negative consequences of contact with ticks

On a note

Be that as it may, one should not relax either, since only the correct and timely measures taken will minimize the likelihood of undesirable consequences.

First you need to remove the tick. This is easy to do on your own, using, for example, tweezers or special devices to extract ticks.

After removing the tick, the wound must be disinfected (it can be treated with alcohol, brilliant green, iodine or hydrogen peroxide). It is recommended to wash your hands thoroughly with soap. The removed tick should be taken for analysis to ensure it is not infected and appropriate action taken if necessary (e.g. emergency prophylaxis tick-borne encephalitis consists of injections of gamma globulins).

Is there any reliable way protect yourself from a tick bite?

According to experts, repellents do not protect against ticks reliably enough. Even when applied according to the instructions, they fade after a few hours. Also remember that, despite all the claims of aerosol manufacturers, there are no anti-tick drugs that are applied directly to the body, and repellents that protect against mosquitoes and midges are powerless against ticks.

Currently, the most well-known method of preventing tick-borne encephalitis is vaccination for children from 3 years old and adults, which is recommended to be carried out 3.5 or (in extreme cases) 1.5 months before leaving for a dangerous region. However, we must not forget that with borreliosis and other bacterial and viral diseases(there are more than a dozen) transmitted by ticks, this vaccine will not work. For their prevention, other drugs are needed, which have not yet been created. In addition, vaccination has many contraindications.

Going to the cottage:

• take care of the right equipment - light clothes(it is easier to notice a tick on it) with tight-fitting cuffs, trousers tucked into shoes;
• on the suburban area try to keep the grass cut short;
• every morning walk through the area with the so-called flag, which you can make yourself from a large piece of flannel or waffle fabric attached to a stick. By running such a flag on the grass and turning the fabric over, you can collect lurking ticks;
• While walking, inspect yourself every 30 minutes to notice ticks that have landed on your skin or clothing in time.

Everyone is at risk

Alas, it is not. And although 70% of cases of tick-borne viral encephalitis are most often recorded in Siberia and the Urals, among the disadvantaged territories in terms of the incidence of this disease are Tver, Yaroslavl, Kostroma, Leningrad region and even several districts of the Moscow region. Among the natural foci of tick-borne borreliosis, in addition to the above, there are also Tomsk, Sverdlovsk, Vologda region. Every year in Russia over 500,000 applications are registered in medical institutions about bites. Tick ​​attacks are not uncommon in city parks.

The first period of activity of ticks begins in April and lasts until mid-June. The largest number bites are recorded in May. The second "wave" begins in August and ends only by October. Separate bites are recorded in March, and in November, and even in January.