Helminths

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

Doctors estimate the extent of infection with worms in our country at 270 cases per 100 thousand of the population, but the actual incidence, according to experts, is several times higher. This is because often a person does not even notice that an uninvited guest has settled in his body. If the helminths do not manifest themselves in any way, then the disease will not be diagnosed for decades.

Everything about helminths

Parasitic worms, helminths or worms?

This huge group of living things 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 live in another organism - in its tissues and organs. After all, we are talking about worm-like creatures that are ideally adapted to live long in the body of an infected animal and reproduce effectively.

Accordingly, helminths are parasitic worms. The term "helminths" was once introduced by Hippocrates. Among the people, these nasty creatures are also called worms - from the ancient Greek word that simply means a parasitic worm.

So, if we talk about helminths, we will not be mistaken and call them worms or parasitic worms. And when we talk about helminthiasis, these diseases can also be called "parasitic infections".

A variety of helminths in humans

In total, scientists are aware of 287 types of helminths that can parasitize on humans. Only 65 species have been identified in our country, 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, where you can find ascaris, pinworm, three types of tapeworm, broadband worm, hookworm, etc. Vlasoglav single-handedly occupies the large intestine.

In the liver, more precisely in its bile ducts, as well as in the gall bladder, leeches, opisthorchis etc. are found. The lung fluke settles in the lungs. Trichinella affects the muscles. The adult pork 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 the urogenital system.

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

Types of helminths that live in humans

Helminths, the types of which are the most interesting for 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 has the shape of a circle and in flat worms it is flattened in the direction from the conditional back to the conditional belly. Flatworms are further divided into two classes: leeches (trematodes) and tapeworms (cestodes).

• Nematodes. Most nematodes are inhabitants of the human intestine. This group includes roundworms, pinworms, Trichinella, whipworms, etc. , which differ greatly in size - from a few millimeters to 1. 5 meters. They all have their own well-developed digestive systems. Nematodes have both males and females. In adults it is not difficult to tell them apart: females are usually twice as large, and in addition, in males the "tail" is turned towards the "belly".
• Trematodes. The body of trematodes is similar in shape to a leaf or a lancet, and in size it cannot be compared with other helminths: these are small worms, from a few millimeters to 3. 55. 5 cm long. Unlike roundworms, trematodes have a pair of suction cups in their mouth and abdomen. Your digestive system is still in its infancy. A significant part of the species from this group are hermaphrodites, that is, they combine the characteristics of both sexes. The exception are schistosomes, which have both males and females.
• Cestodes. Cestodes are worms that are a long ribbon that is broken into short segments, at one end there is a head with hooks and suction cups. These worms live exclusively in the small intestine - their entire body does not fit into any other organ. And this is not surprising, because the length of tapeworms can reach 10-11 meters. They don't need a digestive system at all as they get everything they need from the food a person eats. All tapeworms are hermaphrodites.

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

Depending on whether a certain species of worm has reached a stage of development in the body of an intermediate host, one also speaks of bio- and geohelminthiasis.

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

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

In addition, depending on which hosts play a key role in the life of helminths, anthropo- 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 agent 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 do not disrupt life and prosperity. This category includes opisthorchiasis, diphyllobothriasis, etc.

How does a 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 pinworms, the eggs of which a child can pick up in a sandpit (a contact household route to spreading infection). The food route (via food) is characteristic of roundworms - through contaminated vegetables or fruits and trematodes that enter the body when eating contaminated but poorly thermally processed seafood or meat, etc.

However, food is not the only way helminths get infected. Inhaling dust can cause eggs to enter the human body. Hookworms and schistosomes enter the body through the skin - and they are called contagious worms, and the route of infection is percutaneous. And since the schistosome can be ingested while swimming in a pond, this route of infection is also called aquatic.

The filamentous plant lives in the tropics, it is also usuryeria that spreads with the help of a mosquito bite. And this is a vector-borne route of infection.

Helminth infection can also occur through contact with animals - infected cats and dogs. Usually humans get roundworms (Toxocar etc) and tapeworms from animals. Pets carry helminth eggs through their fur when licking. A person who has petted such an animal and does not immediately wash their hands afterwards risks getting an infection in the mouth. Another option for worm infestation is to clean the litter box without gloves.

How do helminths affect the body?

Mechanical shock

This category includes all actions of helminths that violate the integrity of the host's tissues. Adult helminths with hooks and suction cups, for example, fix themselves with their help and damage the gastrointestinal mucosa in the process. As a result, in the area of the localization of the worm, tissue erosion develops, ulcers are formed, and the nutritional processes of the mucous membrane are disturbed, which can even lead to its death (necrosis).

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

Eventually, the cysticercus, which has invaded the brain and is actively growing there, compresses the tissues, which can lead to a person's death.

Host malnutrition

First, the helminths themselves "steal" their host by consuming the food they ate. Second, some human helminths feed themselves on blood - hookworms and whipworms do, or they ingest the substances necessary for hematopoiesis. Therefore, against the background of parasitic infection, anemia can develop.

In the case of prolonged chronic infection with helminths, which absorb metabolically valuable nutrients, a protein-calorie deficiency is diagnosed.

Poisoning of the human body with helminth poisons

The metabolic products of the whipworm and tapeworm destroy erythrocytes, Ascaris secretions cause capillary dilation and, as a result, bleeding.

Some parasitic worms pose an increased risk after death and release substances with necrotic and hemotoxic properties.

Allergy to helminth proteins

Helminths are alien 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. When sensitizing to these antigens, antibodies are formed - immunoglobulins IgE and IgG-4. Upon contact with mast cells, basophils and eosinophils, these antibodies cause their destruction. At the same time, substances are released 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. Tapeworms located in the small intestine, as mentioned above, can cause a decrease in stomach acid. 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 and thus ensure a comfortable life for a long time. This is an evolutionary adaptation that they acquire in the course of adapting to a narrowly limited range of hosts. However, the suppression of the human immune system leads to an increased susceptibility to other infections and diseases.

Cancer risks

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

Phases of the course of helminthiasis

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

There are 4 main phases during helminthiasis:

• Acute (early) phase of helminthiasis. At this stage, the causative agent of the infection penetrates the human body, which leads to a sensitization of the body to the proteins of the helminth. The first symptoms of helminths appear 2-4 weeks after infection. Usually during this period allergic reactions develop - itchy rashes, conjunctivitis, cough, swollen lymph nodes, inflammatory processes in 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 ultimately determined to have a permanent place of residence, after which the helminthiasis moves 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 get into the external environment or spread to other organs of the body. Helminths in children can provoke muscle spasms, seizures - epileptic, hysterical, etc. Doctors note that all these signs of helminthiasis are non-specific and resemble the symptoms of dozens of other diseases, making them impossible to diagnose. More precisely, there are several helminths, the symptoms of which are very characteristic, but they too should be checked with a series of tests.
• Exodus phase. This term means either the patient's full recovery 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 a helminth invasion (the invasion of helminths into its body) affects 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 the helminth, the properties of its nutritionaland development cycle.

In general, doctors distinguish the following symptoms of helminth infection, in the presence of which you should consult a doctor and undergo an examination:

• periodic frequent nausea and vomiting, abdominal pain;
• frequent allergies;
• Insomnia, chronic fatigue, irritability;
• Itching in the anal area;
• frequent urinary tract infections;
• chronic gastrointestinal diseases, dysbiosis;
• Symptoms of chronic poisoning of the body: frequent colds, blue circles under the eyes, paleness, enlarged lymph nodes;
• Vulvovaginitis;
• an increased level of eosinophils in the results of a blood test;
• retarded growth and weight.

The question arises: if helminths have settled in the body, do the symptoms of an infection become apparent immediately or only after a while? Are there any helminths that are difficult to spot, signs of infection? Doctors point out that with a non-intense invasion, the first symptoms of helminthiasis may appear in a month or two and after a few years. That is, no signs of helminth infection are visible during this time.

Manifestations of helminth infection in children

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

What ailments 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, children against the background of infection with helminths developed immune disorders (19%) and bruxism, that is, teeth grinding (16%). It's a paradox, but these two symptoms are generally considered to be signs of helminths by the population.

Diagnosis of helminthiasis

What are the tests for helminths?

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

The most common types of analysis for helminths are examination 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 needed for diagnosis (schistosomiasis of the genitourinary system, enterobiasis), a study is carried out for helminths of the patient's muscles (trichinosis) with a sample of material through a biopsy method.

How is the 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 tests, in which you need to collect feces for helminth eggs. It is better to give the sample to the laboratory on the same day (in the case of strongyloidosis and ankylostomiasis - 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 0-4 ° C, freezing is absolutely impossible. In principle, it is possible to use special preservatives that allow samples to be stored for up to several months.

Perianal cockroaches - analysis for helminth eggs

Perianal scraping is used to diagnose helminthiasis such as enterobiasis, teniasis, teniarinchiasis, etc. In contrast to stool analysis for helminths, the scraping material is collected from the skin around the anus with a cotton swab, wooden spatula, glass eye stick or adhesive tape. The procedure for collecting material for the analysis of helminth eggs is carried out early in the morning, and the patient should not wash in the evening or in the morning.

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

Analysis of the contents of the duodenum (bile)

The bile is removed with an empty nasogastric tube. Since this method is invasive (as opposed to methods such as feces for helminth eggs, urine collection, and perianal scraping), it is only prescribed if there is a strict indication that there is a justified suspicion of a specific helminthiasis. The bile is examined for strongyloides and hookworm larvae, and individual portions of bile are also examined for the presence of helminth eggs that live in the pancreas and liver ducts.

Blood test for helminths

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

The most important serological method today is the Enzyme-Linked Immunosorbent Assay (ELISA), which is characterized by high specificity and the highest sensitivity (90%) among all other methods. That said, you can pretty much determine what type of helminths a person is infected with, and you can spot them, even if there are very few of them. The ELISA reliability is 60%. ELISA is extremely relevant for the detection of so-called tissue helminthiasis, in which worms parasitize in organs and tissues of the patient (trichinosis, toxocariasis).

Instrumental methods of helminth diagnostics

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

If the analysis of feces on helminths, blood and other methods did not show any effect, then in this case, using the methods of instrumental diagnostics - X-ray, ultrasound, computed tomography, etc. - tissues of the liver and can such parasites. detected spleen, enlargement of the lymph nodes in the latter, finally in some cases - echinococcus, large accumulations of intestinal worms - you can see the parasites for yourself.

Treatment of helminthiasis

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

• Cucurbitin (pumpkin seeds);
• Artemisinin annual wormwood);
• Ascaridol (ambrosia);
• Santonin (citrine wormwood);
• Thymol (thyme);
• Pelletierin (pomegranate root);
• Carvacrol (oregano, thyme, bergamot);
• Diospirol (persimmon);
• Arecoline (arec palm);
• Pyrethrins (Dalmatian chamomile);
• Tremulacin (aspen);
• Nicotine (tobacco) and its isomer anabazine (tobacco and leafless stall);
• Emetine (emetic root).

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

Conclusions

• Helminthiasis is one of the most common diseases in the world. Everyone around them has a 100 percent chance of having people and animals infected with helminths.
• However, if the number of individuals in the body is small, and the body itself 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 an annual test does not guarantee that a person really does not have helminths.
• Signs of worms in the body can be very similar to symptoms of other diseases. Therefore, if for any reason, for any reason, treatment for bowel disease and other similar conditions does not help, consider testing 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 undergo a random examination on your own - it is better to see a doctor: on the basis of the entirety of symptoms, nutritional data and travel dates, he will select tests that can be used to determine exactly whether a person is affected by helminths or helminthsNot.
• You cannot prescribe pills for helminths yourself. A remedy for worms can have contraindications for a particular patient and, if used incorrectly, cause serious harm.