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, every fourth person on the planet is infected with one or another helminth. And it is not surprising, because you can catch this infection almost anywhere in the world. Doctors equate the incidence of helminthiasis with the spread of influenza and ARVI.

Doctors estimate the rate of worm infection in our country as 270 cases per 100 thousand population, 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 is placed on his body. If helminths do not appear in any way, then the disease can remain undiagnosed for decades.

Everything about helminths

Parasitic worms, poisons or worms?

This broad group of living beings has several names at once. First of all, we are talking about parasites, that is, living organisms that live at the expense of others. In addition, 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 long in the body of an infected animal and reproduce effectively.

Accordingly, helminths are parasitic worms. The very term "helminths" was once coined by Hippocrates. Among humans, these nasty creatures are also called worms - from the ancient Greek word, simply meaning a parasitic worm.

So talking about 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 about 287 species 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 all over the body, and each species has its own preferences.

Basically, worms prefer the gastrointestinal tract and mainly the small intestine, in which you can find ascaris, pinworms, three types of worms, broad bands, worms, and so on. Vlasoglav occupies only the colon.

In the liver, more precisely in its bile ducts, as well as in the gallbladder, can be found lightning, opisthorchis, etc. Lung current is placed in the lungs. Trichinella affects muscles. Adult swine tapeworm lives in the small intestine, and its larvae (cysticercus) can be found in the eyes and central nervous system. Schistosomes (helminths from the tropics) prefer the veins of the gastrointestinal tract and genitourinary system.

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

Types of helminths that live 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 worm body: in roundworms it is circular in shape and in flatworms it is flattened in the direction from the condition back to the conditioned abdomen. Flatworms are further divided into two classes: lightning rodents (trematodes) and tapeworms (cestodes).

• Nematodat. Most nematodes are inhabitants of the human intestine. This group includes roundworms, tapeworms, Trichinella, worms, etc. , Very different in size from each other - from a few millimeters to 1. 5 meters. They all have their own well-developed digestive system. Nematodes have male and female. It is not difficult to distinguish them in adults: females are usually twice as large, and in addition, in males, the "tail" is distorted towards the "belly".
• Trematodat. The body of trematodes resembles a leaf or a skin in shape and can not be compared in size with other helminths: these are small worms, from a few millimeters to 3. 5-5. 5 cm long. Unlike roundworms, trematodes have a pair of suckers in their mouth and abdomen. Their digestive system is in its infancy. A considerable part of the species from this group are hermaphrodites, that is, they combine the characteristics of both sexes. Exceptions are schistosomes, which have both males and females.
• Cestodet. Cestodes are worms, which are a long band cut into short segments, at one end of which there is a hooked head and sucker. These worms live exclusively in the small intestine - their whole body does not fit into any other organ. And this is not surprising, because the length of the worms 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 the helminths live in the larval stage is called an intermediate host (they can be animals, fish, mollusks, and, of course, humans), and the bearer of the adult forms is called the final host.

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

• Geohelminths do not have such a stage. Worm eggs fall to the ground, where they wait until, by the will of fate, they are brought to the body of the future owner. Geohelminths include worm worms, roundworms, hookworms, and so on.
• Biohelminths have such a stage and may have several hosts. Examples include Trichinella, stripes, schistosomes, all flatworms, etc.

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

In addition, depending on what awaits hosts a major role in the life of helminths, anthroponoses and zoonoses are isolated.

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

How does helminth infection occur?

Most often, people become infected with worms, so to speak orally, that is, by swallowing helminth eggs. The most striking example is the pinworms, the eggs of which a child can take in a sandbox (a contact-way to spread the infection from the family). The food route (through food) is characteristic of roundworms - through contaminated vegetables or fruits and trematodes that enter the body when eating contaminated but poorly processed seafood or meat, etc.

However, food is not the only route of helminth infection. Eggs can enter the human body through the absorption of dust. And rash worms and schistosomes enter the body through the skin - and they are called contagious worms, and the route of infection is percutaneous. And since schistosomes can be acquired 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 spreads with the help of mosquito bites. And this is a pathway transmitted by the vector of transmission of infection.

Helminth infection can also occur through contact with infected animals - cats and dogs. Usually, humans get roundworms (toxocarium, etc. ) and tapeworms from animals. Pets, in the process of licking, hold helminth eggs through their fur. A person, after petting such an animal and not washing his hands immediately afterwards, risks injecting an infection into his mouth. Another option for worm infection is to clean the garbage can without gloves.

How do helminths affect the body?

Mechanical impact

This category includes any action of helminths in which the integrity of the host tissues is compromised. For example, adult helminths with hooks and suction cups are fixed with their help, while damaging the gastrointestinal mucosa. As a result, tissue erosion develops in the area of worm localization, ulcers form and the nutritional processes of the mucosa are disrupted, which can also lead to its death (necrosis).

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

Finally, the cystic, which has entered the brain and is actively growing there, squeezes the tissue, which can lead to a person’s death.

Malnutrition of the host

First, the poisons themselves "rob" their host, consuming the food they have eaten. Second, some human helminths feed on their own blood - this is what fat worms and worms do, or they get the substances needed for hematopoiesis. Therefore, against the background of a parasitic infection, anemia may develop.

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

Poisoning of the human body with helminth toxins

Metabolic products of worms and tapeworms destroy erythrocytes and ascaris secretions cause capillary dilation and, as a result, hemorrhages.

Some parasitic worms begin to pose an increased risk after death, releasing substances with necrotic and hemotoxic properties.

Allergy to helminth proteins

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

Suppression of body defense

The negative effect of helminths on the body can be indirect. Tapeworms, located, as mentioned above, in the small intestine, can cause a decrease in stomach acidity. And this significantly reduces 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 gained by them during adaptation to a narrowly defined host circle. But suppressing the human immune system leads to increased susceptibility to infections and other diseases.

Risks of cancer

Some chronic helminthiasis significantly increases the likelihood of cancer. Parasites during 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, clonorrhea, etc.

Stages of the course of helminthiasis

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

During helminthiasis, there are 4 main stages:

• Acute (early) stage of helminthiasis. At this stage, the causative agent of the infection enters the human body, which leads to the sensitization of the body to helminth proteins. The first symptoms of helminths appear 2-4 weeks after infection. Usually during this period, allergy-like reactions develop - itchy skin rash, conjunctivitis, cough, swollen lymph nodes, inflammatory processes in the joints, tests show an increased concentration of eosinophils, etc.
• Latent phase (latent). At this stage, the helminth develops into an adult state and is eventually defined by a place of permanent residence, after which the helminthiasis progresses to a chronic stage.
• Chronic phase (late). 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 pain, seizures - epileptic, hysterical, etc. Doctors note that all these signs of helminthiasis are not specific and are similar to the symptoms of dozens of other diseases, so it is impossible to diagnose them. More precisely, there are some helminths, the symptoms of which are very characteristic, but even they should be checked using a number of tests.
• Exodus phase. This term means either complete recovery of the patient, or his disability against the background of complications of helminthiasis. These include malignant tumors in opisthorchiasis and schistosomiasis, liver cirrhosis, etc.

Helminths: symptoms of infection

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

Generally, physicians distinguish the following symptoms of helminth infection, in the presence of which you should consult a physician and undergo an examination:

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

The question arises: if helminths are placed in the body, will the symptoms of the infection appear immediately or only after a while? Are there poisons that are difficult to detect signs of infection? Doctors point out that with a non-intensive invasion, the first symptoms of helminthiasis can appear within a month, or two, and after a few years. That is, during this time, no sign of infection with helminths 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 hygienic skills, as well as close contact with the environment, which can be a source of helminth eggs. Such an environment could be a sandbox on a playground, beds in grandma’s dacha, someone else’s toys played by an infected child, and so on.

Which complaints are most often recorded when children are infected with intestinal nematodes:

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

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

Diagnosis of helminthiasis

What are helminth tests?

It should be understood that helminth analysis alone is not enough. None of the existing methods for detecting parasitic worms on their own can serve as a basis for establishing a definitive diagnosis. According to doctors, in some cases, a positive result can only be achieved 8-10 times! There can be many reasons for this: females lay eggs at different intervals that do not coincide with the sampling moments, the biomaterial samples turned out to be empty because they were taken in the wrong place, the disease was at such a stage that it wasdetermined by methods that were chosen almost impossible, & c.

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

Less often, urine is needed for diagnosis (schistosomiasis of the genitourinary system, enterobiasis), a study was performed on the patient's muscle helminths (trichinosis) with a sampling of the material by a biopsy method.

How are feces for helminth eggs tested?

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

Perianal scraping - analysis for helminth eggs

Perianal abrasions are used to diagnose helminthiasis such as enterobiasis, teniasis, teniarinkiasis, etc. Unlike stool analysis for helminths, scratch material is collected from the skin around the anus using a cotton swab, wooden spatula, glass eye sticks or adhesive tape. The procedure for collecting material for analysis for helminth eggs is performed early in the morning, and the patient should not bathe himself 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 worms lay eggs at regular intervals, and if you do not catch the "right moment", then you can rest assured that there are no eggs - no worms.

Analysis of duodenal (bile) contents

Gallbladder collection is performed using an empty stomach tube. Since this method is invasive (unlike methods such as feces for helminth eggs, urine collection, and perianal abrasions), it is prescribed only for strict indications when there is reasonable suspicion of a specific helminthiasis. It has even been examined for strongyloides and worm larvae, and individual parts of the gallbladder have also been analyzed for the presence of helminth eggs living 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 to them.

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

Instrumental methods of helminth diagnosis

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 that is resistant to external influences. They can also be hidden in tissues that are to some extent protected from the body's inflammatory reactions - such is the spinal cord. Certain types of worms have their own means of protection - anti-enzymes. Those worms that can reproduce sexually exchange genetic information. Given the speed of their reproduction and the renewal of generations, it is not surprising that such poisons over time become less vulnerable to the 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 instrumental diagnostic methods - X-rays, ultrasound, computed tomography, etc. liver tissue and spleen, enlargement oflymph nodes in the latter, recently, in some cases - echinococcus, large groups-tangles of intestinal worms - you can see the parasites themselves.

Treatment of helminthiasis

Traditional medicine, through trial and error, discovered a number of plants with anthelmintic properties: aspen, squash, chamomile, tansy, male fern, etc. Later, in the days of scientific pharmaceutics, scientists isolated active substances from them that actually gave an effect:

• cucurbitin (pumpkin seeds);
• annual wormwood artemisinin);
• ascaridol (ambrosia);
• santonin (citrine wormwood);
• thymol (thyme);
• pelletierin (pomegranate root);
• carvacrol (oregano, thyme, bergamot);
• diospyrol (persimmon);
• arecolin (palm arec);
• pyrethrins (Dalmatian chamomile);
• tremulacin (aspen);
• nicotine (tobacco) and its isomer anabazine (tobacco and leafless garden);
• emetine (emetic root).

And today, a significant portion of anthelmintic drugs contain the same active substances that once provided the anthelmintic effect in decoctions and tinctures.

conclusions

• Helminthiasis is one of the most common diseases in the world. Every 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 is generally healthy, then the disease can be asymptomatic for many years, without manifesting itself in any way.
• Even a regular medical examination every 3 years or taking tests once a year does not guarantee that a person really has no poison.
• The signs of worms on 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 does not help consistently, you should think about taking tests for helminths.
• According to the results of an analysis for helminths, the diagnosis of helminthiasis has not been made, as both false-positive and false-negative results are possible. You should not try to undergo an independent examination independently by chance - it is better to consult a doctor: based on the totality of symptoms, nutritional data and travel data, he will choose tests that will make himpossible to find out exactly whether a person has helminths or not.
• You can not prescribe pills for helminths yourself. A worm medicine may have contraindications for a particular patient and cause serious harm if used incorrectly.