helminths

Helminthiases, or diseases caused by helminths, are among the most common among humans. According to rough estimates by experts from the World Health Organization, one in four people on the planet is infected with one or another helminth. And it's not surprising, because you can get this infection almost anywhere in the world. Doctors identify the incidence of helminthiasis with the spread of influenza and ARVI.

Doctors estimate the extent of worm infection in our country in 270 cases per 100 thousand inhabitants, but the real incidence, according to experts, is several times higher. This is due to the fact that often a person does not even notice that an uninvited guest has settled in her body. If helminths do not manifest themselves in any way, the disease could remain undiagnosed for decades.

All about helminths

Parasitic worms, helminths or worms?

This large group of living beings has several names at the same time. We are talking first of all about parasites, that is, living organisms that live at the expense of others. Furthermore, we are talking about endoparasites, that is, living inside another organism, in its tissues and organs. Finally, we are talking about worm-like creatures, which are ideally adapted to live in the body of an infected animal for a long time and reproduce effectively.

Consequently, helminths are parasitic worms. The very term "helminths" was once introduced by Hippocrates. Among the people, these unpleasant creatures are also called worms - from the ancient Greek word, which means just a parasitic worm.

So, speaking of helminths, we will not go wrong, calling them worms or parasitic worms. And if we are talking about helminthiasis, these diseases can also be called "parasitic infections".

A variety of helminths in humans

In total, scientists know 287 types of helminths that can parasitize humans. In our country only 65 species have been identified and only 24 species are among the most common.

Helminths in humans live throughout the body, and each species has its own preferences.

Basically, worms prefer the gastrointestinal tract and mainly the small intestine, in which roundworms, pinworms, three varieties of tapeworms, broad tapeworms, hookworms, etc. can be found. Vlasoglav alone occupies the large intestine.

In the liver, more precisely in its bile ducts, as well as in the gallbladder, flukes, opisthorchis, etc. can be found. . Pulmonary fluke settles in the lungs. Trichinella affects the muscles. The adult pig tapeworm lives in the small intestine and its larvae (cysticercus) are found in the eyes and central nervous system. Schistosomes (helminths of the tropics) prefer the veins of the gastrointestinal tract and the genitourinary system.

Heartworms are generally ubiquitous - found in the lymphatic system and closed body cavities - in the retroperitoneal space, pericardial sac, and their larvae are usually found in the blood or skin.

Types of helminths living in humans

Helminths, the types of which are most interesting to doctors, are divided into two main types: flat and round (nematodes). The classification is based on the cross section of the body of the worm: in round worms it has the shape of a circle, and in flat worms it is flattened in the direction from the conditional to the conditional abdomen. Flatworms are further divided into two classes: flukes (trematodes) and tapeworms (cestodes).

• Nematodes. Most nematodes are inhabitants of the human intestine. This group includes roundworms, pinworms, Trichinella, whipworms, etc. , Very different in size from each other - from a couple of millimeters to 1. 5 meters. They all have their own well-developed digestive systems. Roundworms have both males and females. It is not difficult to distinguish them in adults: females are generally twice as large, and in addition, in males, the "tail" is twisted towards the "abdomen".
• Trematodes. The body of the flukes resembles the shape of a leaf or a lancet and is not comparable in size with other helminths: they are small worms, from a few millimeters to 3. 5-5. 5 cm long. Unlike roundworms, flukes have a pair of suckers in their mouth and abdomen. Their digestive system is in its infancy. A significant part of the species of this group are hermaphrodites, that is, they combine the characteristics of both sexes. The exception is schistosomes, which have both males and females.
• Cestodes. Tapeworms are worms, which are a long ribbon fragmented into short segments, at one end of which is a head with hooks and suckers. These worms live exclusively in the small intestine - their entire body does not adapt to any other organ. And this is not surprising, because the length of tapeworms can reach 10-11 meters. They do not need a digestive system at all, as they absorb everything they need from the food a person eats. All tapeworms are hermaphrodites.

The organism in which helminths at the larval stage live is called the intermediate host (it can be animals, fish, mollusks and, of course, humans) and the carrier of adult forms is called the final host.

Depending on whether a certain type of worm has a stage of development in the body of an intermediate host, they also speak of bio and geohelminthiasis.

• Geohelminths do not have such a stage. The eggs of the worms fall into the ground, where they wait until, by the will of fate, they are carried into the body of the future owner. Geohelminths include whipworms, roundworms, hookworms, etc.
• Biohelminths have such a stage, and there may be several hosts. Examples include Trichinella, tapeworms, schistosomes, all flatworms, etc.

Some scientists now, by the mechanism of transmission, distinguish a third group of worms - contagious helminths, which include pinworms (geohelminths) and dwarf tapeworms (biohelminths). These parasites are spread by contact with an infected person.

In addition, depending on which hosts play a key role in the life of helminths, anthroponoses and zoonoses are isolated.

• The first category includes helminthiasis, in which a person is an obligatory stage in his life cycle: ascariasis, enterobiasis, etc.
• Zoonoses include helminthiases, the causative agents of which can successfully exist without a person, but at the same time our species is also susceptible to them, and if an infection occurs, the worms will not interfere with life and prosperity. This category includes opisthorchiasis, diphyllobothriasis, etc.

How does helminth infection occur?

Most often, people are infected with worms, as it were, orally, that is, by swallowing helminth eggs. The most striking example is pinworms, the eggs of which a child can collect in a sandbox (a home way of spreading the infection). The food pathway (through food) is characteristic of nematodes - through contaminated vegetables or fruit and flukes that enter the body when eating contaminated but thermally poorly processed fish or meat, etc.

However, food is not the only route of helminth infection. Eggs can enter the human body by inhaling dust. And hookworms and schistosomes enter the body through the skin - and they are called contagious worms, and the route of infection is percutaneous. And since schistosome can be picked up while swimming in a pond, this route of infection is also called aquatic.

In the tropics, the filamentous plant lives, it is also wuchereria, which is spread with the help of a mosquito bite. And this is a route of transmission of vector-borne infection.

Helminth infection can also occur through contact with infected animals - infected cats and dogs. Usually, people get roundworms (toxocar, etc. ) and tapeworms from animals. Pets, in the process of licking, carry helminth eggs through their fur. A person, having stroked such an animal and not washing his hands right away, risks injecting himself with an infection in his mouth. Another option for worm infestation is to clean the litter box without gloves.

How do helminths affect the body?

Mechanical impact

This category includes any action of helminths in which the integrity of the host's tissues is violated. For example, adult helminths with hooks and suckers repair themselves with their help, damaging the gastrointestinal mucosa. As a result, tissue erosion develops in the area of localization of the worm, ulcers are formed and the nutritional processes of the mucous membrane are disrupted, which can even lead to its death (necrosis).

Moving through the body, the so-called migratory larvae can also cause bleeding and inflammation in damaged areas - this makes it easier for them to penetrate deep into the tissues. And helminths in the intestines often provoke the development of appendicitis, intestinal obstruction and even its rupture.

Finally, the cysticercus, which has entered the brain and is actively growing in it, compresses the tissues, which can lead to the death of a person.

Host malnutrition

First, the helminths themselves "rob" their host, consuming the food they ate. Secondly, some human helminths feed on blood themselves - this is what hookworms and whipworms do, or they take the substances necessary for hematopoiesis. Therefore, against the background of a parasitic infection, anemia can develop.

With prolonged chronic infection with helminths, which absorb metabolically valuable nutrients, a calorie-protein deficiency is diagnosed.

Poisoning of the human body with helminthic toxins

The metabolic products of whipworm and tapeworm destroy erythrocytes and ascarid secretions cause capillary expansion and, consequently, hemorrhages.

Some parasitic worms begin to pose a greater danger after death, releasing substances with necrotic and hemotoxic properties.

Allergy to helminth proteins

Helminths are organisms foreign to us, so our body perceives many proteins secreted by them (in the process of vital activity or after death) as a potential danger and can consider them as antigens. In the course of sensitization to these antigens, antibodies are formed: immunoglobulins IgE and IgG-4. These antibodies, in contact with mast cells, basophils and eosinophils, cause their destruction. At the same time, there is a release of substances that trigger allergic reactions (allergy mediators) - histamine, serotonin, heparin, etc.

Suppression of the body's defenses

The negative effect of helminths on the body can be indirect. The tapeworms, located, as mentioned above, in the small intestine, can cause a decrease in gastric acidity. And this significantly reduces the protection against the penetration of pathogenic bacteria into the body.

Many helminths have immunosuppressive abilities, that is, they suppress the body's defenses, thus ensuring a comfortable existence for a long time. This is an evolutionary adaptation acquired by them in the course of adapting to a small circle of hosts. But the suppression of the human immune system leads to greater vulnerability to other infections and diseases.

Cancer Risks

Some chronic helminthiases significantly increase the likelihood of cancer. Parasites in the course of their vital activity destroy tissues and organs, and thus provoke the development of malignant tumors in this place. Cancer often develops against the background of opisthorchiasis, schistosomiasis, clonorchiasis, etc.

Stages of the course of helminthiasis

What are the signs of helminthiasis? After the worms have entered the body, the symptoms of infection will depend on the stage of the disease.

During helminthiasis, there are 4 main stages:

• Acute (early) phase of helminthiasis. At this stage, the causative agent of infection enters the human body, which leads to sensitization of the body to helminth proteins. The first symptoms of helminths appear 2-4 weeks after infection. Usually during this period, allergic-type reactions develop: itchy rashes, conjunctivitis, cough, swollen lymph nodes, inflammatory processes of the joints, analyzes show an increased concentration of eosinophils, etc.
• Latent (latent) phase. At this stage, the helminth develops into an adult state and is finally determined with a permanent dwelling place, after which the helminthiasis passes into a chronic stage.
• Chronic (late) phase. At this stage, adult helminths actively reproduce, producing tens and hundreds of thousands of eggs and larvae, which enter the external environment or spread to other organs of the body. Helminths in children can provoke muscle cramps, convulsions - epileptic, hysterical, etc. Doctors note that all these signs of helminthiasis are non-specific and are similar to the symptoms of dozens of other diseases, so it is impossible to diagnose them. More precisely, there are several helminths, the symptoms of which are very characteristic, but they too should be checked using a series of tests.
• Phase of the exodus. This term means the complete recovery of the patient or her disability against the background of the complications of helminthiasis. These include malignant tumors in opisthorchiasis and schistosomiasis, liver cirrhosis, etc.

Helminths: Symptoms of Infection

How the helminthic invasion (the invasion of helminths into his body) will affect the human body is determined by many factors: the method of penetration, the extent of the infection, the duration of the disease and the lifespan of thehelminth, the characteristics of its nutrition and development cycle.

In general, doctors distinguish the following symptoms of helminth infection, in the presence of which it is necessary to consult a doctor and undergo an examination:

• periodic frequent nausea and vomiting, abdominal pain;
• frequent allergies;
• sleep disturbances, chronic fatigue, irritability;
• itching in the anal area;
• frequent urinary tract infections;
• chronic gastrointestinal diseases, dysbiosis;
• symptoms of chronic intoxication of the body: frequent colds, blue circles under the eyes, pallor, swollen lymph nodes;
• vulvovaginitis;
• an increase in the level of eosinophils in the results of a blood test;
• growth and weight retardation.

The question arises: if the helminths have settled in the body, will the symptoms of the infection be immediately visible or only after a while? Are there any helminths that are difficult to detect signs of infection? Doctors point out that with a non-intensive invasion, the first symptoms of helminthiasis can appear in a month or two and after a few years. That is, during this period, no signs of helminth infection will be visible.

Manifestations of helminth infection in children

Helminths are more common in children than in adults. This is explained by the lack of hygiene skills and close contact with the environment, which can be a source of helminth eggs. Such an environment can be a sandbox on a playground, beds in a grandmother's dacha, someone else's toy played by an infected child, etc.

What complaints are most often recorded when children are infected with intestinal roundworms:

• dysfunction of the gastrointestinal tract - 75% of children;
• allergic reactions - 71%;
• sleep disturbances - 54%;
• appetite disorders - 44%;
• pain in the abdomen - 40%;
• itching in the anal area - 36%.

Less often, against the background of helminth infection, children developed immune disorders (19%) and bruxism, that is, grinding of teeth (16%). It is a paradox, but these two symptoms are generally regarded by the population as signs of helminths.

Helminthiasis diagnostics

What are the tests for helminths?

It should be understood that helminth analysis alone is not enough. None of the existing methods of detecting parasitic worms per se can serve as the basis for making a definitive diagnosis. According to doctors, in some cases, it is possible to get a positive result only for the 8-10th time! The reasons can be many: the females lay their eggs at different intervals that do not coincide with the sampling times, the biomaterial samples were found to be empty, because they were taken in the wrong place, the disease was in a phase that was determined by the methodswhich were selected almost impossible, etc.

The most common types of analyzes for helminths are the study of feces for helminth eggs, perianal scraping, analysis of duodenal contents, analysis of biomaterials from the patient's lungs, blood test for helminths, etc.

Less often, urine is required for diagnosis (schistosomiasis of the genitourinary system, enterobiasis), a study is conducted for helminths of the patient's muscles (trichinosis) with a sampling of material by a biopsy method.

How is feces tested for helminth eggs?

For the analysis of helminths, 50 g of the patient's feces is enough (this is about 1 tablespoon). Today in the pharmacy you can buy a special clean container for testing, where you will need to collect feces for helminth eggs. It is best to deliver the sample to the laboratory on the same day (for strongyloidosis and hookworm - no later than 4 hours after collection). If necessary, it is possible to store a sample of feces for helminths for no more than a day at a temperature from 0 to 4 ° C, it is absolutely impossible to freeze it. In principle, special preservatives can be used that allow samples to be stored for up to several months.

Perianal curettage - analysis for helminth eggs

Perianal scraping is used to diagnose helminthiasis such as enterobiasis, teniasis, teniarinchiasis, etc. Unlike stool analysis for helminths, scraping material is collected from the skin around the anus using a cotton swab, wooden spatula, glass eye sticks, or duct tape. The procedure for collecting material for the analysis of helminth eggs is carried out early in the morning, and the patient does not have to wash either in the evening or in the morning.

An important point: even a repeated analysis for helminths in this way does not guarantee the reliability of the result in case of enterobiasis. Female pinworms lay eggs at regular intervals, and if you don't catch the "right time", you can be sure there are no eggs - there are no worms.

Duodenal (bile) content analysis

Bile collection is done using an empty stomach tube. Since this method is invasive (unlike methods such as helminth egg feces, urine collection and perianal scraping), it is only prescribed for strict indications when there is a reasonable suspicion of specific helminthiasis. The bile is examined for strongyloids and hookworm larvae, and individual portions of bile are also tested for the presence of helminth eggs that live in the pancreas and liver ducts.

Blood test for helminths

In addition to the above methods, there are also so-called serological methods for the diagnosis of helminthiasis. In this case, a blood test is performed for helminths, more precisely for antibodies against them.

The main serological method today is the enzyme-linked immunosorbent assay (ELISA), which is distinguished by its high specificity and maximum sensitivity (90%) among all other methods. That is, it allows you to fairly accurately determine what kind of helminth a person is infected with and allows you to detect them, even if there are very few of them. The reliability of the ELISA is 60%. ELISA is extremely relevant for the detection of so-called tissue helminthiasis, in which worms parasitize within the patient's organs and tissues (trichinosis, toxocariasis).

Instrumental methods of diagnostics of helminths

It is far from always possible to detect helminths using the above methods of laboratory diagnostics, including the use of immunological methods of analysis. Some parasitic worms have a dense capsule resistant to external influences. They can also hide in tissues that are to some extent protected from the body's inflammatory reactions, such as the spinal cord. Some types of worms have their own means of protection - anti-enzymes. Those worms that can reproduce exchange genetic information sexually. Given the speed of their reproduction and the renewal of generations, it is not surprising that such helminths over time become less vulnerable to means of detecting and treating parasitic infections.

If the analysis of feces for helminths, blood and other methods did not give effect, in this case, such parasites can be detected using the methods of instrumental diagnostics: X-ray, ultrasound, computed tomography, etc. tissues of the liver and spleen, enlarged lymph nodes in the latter, finally, in some cases - echinococcus, large clusters-tangles of intestinal worms - it is possible to see the parasites themselves.

Treatment of helminthiasis

Traditional medicine, through trial and error, has discovered a number of plants with antihelminthic properties: aspen, pumpkin, chamomile, tansy, male fern, etc. effect:

• cucurbit (pumpkin seeds);
• artemisinin annual wormwood);
• ascaridol (ambrosia);
• santonina (citrine wormwood);
• thymol (thyme);
• pellet maker (pomegranate root);
• carvacrol (oregano, thyme, bergamot);
• diospirol (persimmon);
• arecolina (arec palm);
• pyrethrins (Dalmatian chamomile);
• tremulacina (aspen);
• nicotine (tobacco) and its anabazine isomer (tobacco and leafless barnyard);
• emetine (emetic root).

And today, a considerable part of anthelmintic drugs contain the same active ingredients that once provided the anthelmintic effect in decoctions and tinctures.

conclusions

• Helminthiasis is one of the most common diseases in the world. Any person in his environment with a 100% probability has people and animals infected with helminths.
• But if the number of individuals in the body is small, and the body itself is generally healthy, the disease can be asymptomatic for many years, without manifesting itself in any way.
• Even a regular medical examination every 3 years or testing once a year does not guarantee that a person does not really have helminths.
• The signs of worms in the body can be very similar to the symptoms of other diseases. Therefore, if the treatment of intestinal diseases and other similar pathologies for some reason persistently does not help, you should think about doing tests for helminths.
• According to the results of an analysis for helminths, the diagnosis of helminthiasis is not made, since both false positive and false negative results are possible. You should not try to independently undergo a random examination - it is better to consult a doctor: based on the totality of symptoms, nutritional data and travel data, he will select tests that will allow you to find out exactly whether a person is helminth or not.
• You can not independently prescribe helminth pills. A remedy for worms can have contraindications for a particular patient and cause great harm if used incorrectly.