Helminths

Helminthiases, or diseases caused by helminths, are among the most common among humans. According to approximate 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 equate the incidence of helminthiasis with the spread of influenza and ARVI.

Doctors estimate the scale of worm infection in our country at 270 cases per 100, 000 inhabitants, but the actual incidence, according to experts, is several times higher. This is due to the fact that many times the person does not even notice that an unwanted guest has installed himself in his body. If helminths do not manifest at all, the disease can go undiagnosed for decades.

all about helminths

Worms, helminths or parasitic worms?

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

Consequently, helminths are parasitic worms. The term "helminths" itself was already introduced by Hippocrates. Among people, these nasty creatures are also called worms - from the ancient Greek, meaning parasitic worm.

So, speaking of helminths, we won't be mistaken in 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 types of helminths that can parasitize in 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 especially the small intestine, where you can find roundworms, pinworms, three varieties of tapeworms, tapeworms, hookworms, etc. Vlasoglav alone occupies the large intestine.

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

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

Types of helminths that live in humans

Helminths, whose types are most interesting to physicians, are divided into two main types: flat and round (nematodes). The classification is based on the cross section of the worm's body: in round worms it is shaped like a circle, and in flat worms it is flattened towards the conditional back to the conditional abdomen. Flatworms are divided into two classes: worms (trematodes) and tapeworms (cestodes).

• Nematodes. Most nematodes are inhabitants of the human intestine. This group includes roundworms, pinworms, trichinae, whipworms, etc. , very different from each other in size - from a few millimeters to 1, 5 meters. They all have their own well-developed digestive system. Nematodes have both males and females. It is not difficult to tell them apart in adults: females are usually twice the size and, moreover, in males, the "tail" is twisted towards the "abdomen".
• Trematodes. The body of trematodes resembles the shape of a leaf or a lancet and cannot be compared in size to other helminths: they are small worms, from a few millimeters to 3, 5-5, 5 cm in length. Unlike roundworms, trematodes have a pair of suckers in their mouths and abdomen. Your digestive system is in its infancy. A significant part of the species in this group are hermaphrodites, that is, they combine the characteristics of both sexes. The exception is schistosomes, which have both males and females.
• Baskets. Cestodia are worms, which are a long ribbon broken into short segments, at one end of which 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 that's not surprising, because tapeworm lengths can reach 10-11 meters. They don't need a digestive system, they absorb 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 an intermediate host (it can be animals, fish, molluscs and, of course, humans), and the carrier 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. The worm's eggs fall to the ground, where they wait until, by the will of fate, they are brought into the body of their future owner. Geohelminths include whipworms, roundworms, hookworms, etc.
• Biohelminths have this stage and can have multiple hosts. Examples include trichinella, tapeworms, schistosomes, all flatworms, etc.

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

Furthermore, depending on which hosts play a key role in the life of helminths, anthroposes 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 helminthiasis, whose causative agents can exist successfully without a person, but at the same time our species is also susceptible to them, and if infection does occur, the worms will not interfere with life and prosperity. This category includes opistorrchiasis, diphylobotriasis, etc.

How does helminth infection occur?

Most of the time, people are infected by worms, so to speak, orally, that is, by swallowing helminth eggs. The most notable example is pinworms, whose eggs a child can catch in a litter box (a form of household contact to spread infection). The food pathway (through food) is characteristic of roundworms - through contaminated vegetables or fruits and trematodes that enter the body when eating contaminated seafood or meat, but poorly thermally processed, etc.

However, food is not the only route to helminth infection. Eggs can enter the human body through dust inhalation. And hookworms and schistosomes enter the body through the skin - and they're called contagious worms, and the route of infection is percutaneous. And because schistosomiasis can be contracted by swimming in a lake, this route of infection is also called the aquatic one.

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

Helminth infection can also occur through contact with animals - infected dogs and cats. Usually, people catch roundworms (pox, etc. ) and tapeworms from animals. Pets, in the process of licking, carry helminth eggs by their fur. A person, after petting one of these animals and not washing their hands immediately, runs the risk of injecting an infection into their mouth. Another option for worm infestation is cleaning the litter box without gloves.

How do helminths affect the body?

mechanical impact

This category includes any helminth actions where the integrity of the host's tissues is violated. For example, adult helminths with hooks and suction cups fix themselves with help, while damaging the gastrointestinal mucosa. As a result, tissue erosion occurs in the area where the worm is located, 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, so-called migratory larvae can also cause bleeding and inflammation in the damaged areas - which makes it easier for them to penetrate deep into tissue. And helminths in the intestines often cause appendicitis to develop, intestinal obstruction, and even rupture.

Finally, cysticercosis, which has entered the brain and is actively growing there, compresses tissue, which can lead to a person's death.

host malnutrition

First, the helminths themselves "steal" their host, consuming the food they ate. Second, some human helminths feed on blood - this is what hookworms and whipworms do, or they take in the substances needed for hematopoiesis. Therefore, in the context of a parasitic infection, anemia can occur.

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

Poisoning the human body with helminthic toxins

The metabolic products of the worm and tapeworm destroy erythrocytes, and roundworm secretions cause capillary expansion and, as a result, hemorrhage.

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

Allergy to helminth proteins

Helminths are foreign organisms 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 may regard them as antigens. During sensitization to these antigens, antibodies are formed - immunoglobulins IgE and IgG-4. These antibodies, when in contact with mast cells, basophils and eosinophils, cause their destruction. At the same time, there is the release of substances that trigger allergic reactions (allergy mediators) - histamine, serotonin, heparin, etc.

Suppression of body defenses

The negative effect of helminths on the body may be indirect. Tapeworms, located, as mentioned above, in the small intestine, can cause a decrease in gastric 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 acquired by them in the course of adapting to a narrow circle of hosts. But suppressing the human immune system increases vulnerability to other infections and illnesses.

Cancer Risks

Some chronic helminthiasis significantly increase the likelihood of cancer. The parasites, in the course of their vital activity, destroy tissues and organs and thus cause the development of malignant tumors in this location. Cancer often develops in the context of opistorchiasis, schistosomiasis, clonorchiasis, etc.

Stages of the helminthiasis course

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

During helminthiasis, there are 4 main phases:

• Acute (early) phase of helminthiasis. At this stage, the causative agent of the infection enters the human body, which leads to the organism's sensitization to helminth proteins. The first symptoms of helminths appear 2 to 4 weeks after infection. Normally, during this period, allergic reactions occur - 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 the adult stage and is finally determined to be a permanent dwelling place, after which the helminthiasis passes into a chronic stage.
• Chronic phase (late). At this stage, the adult helminths actively reproduce, producing tens and hundreds of thousands of eggs and larvae, which enter the external environment or spread to other organs in the body. Helminths in children can cause muscle cramps, seizures - epileptic, hysterical, etc. Doctors note that all of these signs of helminthiasis are non-specific and similar to the symptoms of dozens of other illnesses, so it's impossible to diagnose them. More precisely, there are several helminths whose symptoms are very characteristic, but even they must be checked through a series of tests.
• Exodus Phase. This term means the patient's complete recovery or disability in the context of complications of helminthiasis. These include malignant tumors in opistorchiasis and schistosomiasis, liver cirrhosis, etc.

Helminths: symptoms of infection

How helminth invasion (the invasion of helminths into your body) will affect the human body is determined by many factors: the method of penetration, the extent of infection, the duration of the disease and the lifespan of the helminth, the characteristics of itsnutrition and developmental cycle.

In general, doctors distinguish the following symptoms of helminth infection, in the presence of which you should see a doctor and get tested:

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

The question arises: if helminths have taken root in the body, will the symptoms of the infection be visible immediately or only after some time? Are there 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 within a month, or two, and after a few years. That is, during this time, no signs of helminth infection will be visible.

Manifestations of helminth infection in children

Helminths are more common in children than adults. This is explained by the lack of hygiene 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 a grandmother's dacha, someone else's toy played by an infected child, and so on.

What are the most frequently recorded complaints 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 region - 36%.

Less frequently, in a context of helminth infection, children developed immunological disorders (19%) and bruxism, ie, teeth grinding (16%). It's a paradox, but these two symptoms are generally considered by the population to be signs of helminths.

Diagnosis of helminthiasis

What are tests for helminths?

It must be understood that helminth analysis alone is not sufficient. None of the existing methods for detecting parasitic worms can serve as a basis for a definitive diagnosis. According to doctors, in some cases, a positive result can only be achieved for the 8th to 10th time! The reasons can be many: the females lay eggs at different intervals that do not coincide with the sampling times, the biomaterial samples ended up being empty because they were collected in the wrong place, the disease was at such a stage that it was determined by the methods thatwere selected almost impossible, etc.

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

Less frequently, urine is needed for diagnosis (schistosomiasis of the genitourinary system, enterobiasis), a study for helminths of the patient's muscles (trichinosis) is performed with a sample of material by biopsy method.

How is faeces tested for helminth eggs?

For the analysis of helminths, 50 g of the patient's stool is sufficient (about 1 tablespoon). Today at 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 ankylostomiasis - maximum 4 hours after collection). If necessary, you can store a stool sample for helminths for no longer 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 samples to be stored for several months.

Perianal scraping - analysis of helminth eggs

Perianal scaling is used to diagnose helminthiasis, such as enterobiasis, taeniasis, teniarinchiasis, etc. Unlike stool analysis for helminths, scraping material is collected from the skin around the anus using a cotton swab, wooden spatula, glass rods, or tape. The procedure for collecting material for analysis of helminth eggs is done early in the morning, and the patient should not wash either at night 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. The female moth lays eggs at regular intervals, and if you don't get the "right time" you can be sure there are no eggs - no worms.

Analysis of duodenal content (bile)

Bile collection is performed with an empty stomach tube. Because this method is invasive (as opposed to methods such as feces to helminth eggs, urine collection, and perianal scraping), it is only prescribed for strict indications when there is reasonable suspicion of a specific helminthiasis. Bile is examined for strongyloids and hookworm larvae, and individual portions of bile are also analyzed for the presence of helminth eggs that live in the pancreas and hepatic ducts.

Blood Test for Helminths

In addition to the above methods, there are also so-called serological methods for diagnosing helminthiasis. In that 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 greater sensitivity (90%) among all other methods. That is, it allows you to determine very accurately what kind of helminths a person is infected with and allows you to detect them, even if there are few of them. The reliability of the ELISA is 60%. The ELISA is extremely relevant for the detection of so-called tissue helminthiasis, in which worms parasitize inside the patient's organs and tissues (trichinosis, toxocariasis).

Instrumental methods for diagnosing helminths

It is not always possible to detect helminths using the above laboratory diagnostic methods, including immunological methods of analysis. Some parasitic worms have a dense capsule that is 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. Certain types of worms have their own means of protection - antienzymes. These worms that can reproduce sexually exchange genetic information. Given the speed of their reproduction and generational renewal, it is not surprising that such helminths over time become less vulnerable to means of detection and treatment of parasitic infections.

If stool analysis for helminths, blood and other methods has not been effective, then such parasites can be detected using instrumental diagnostic methods - X-ray, ultrasound, CT scan, etc. liver and spleen tissues, enlarged lymph nodes in the latter, finally, in some cases - echinococci, large tangles-clumps of intestinal worms - you can see the parasites themselves.

Helminthiasis treatment

Traditional medicine, through trial and error, discovered a series of plants with anthelmintic properties: poplar, pumpkin, chamomile, tansy, male fern, etc. It is made:

• cucurbitin (pumpkin seeds);
• wormwood annual artemisinin);
• ascaridol (ambrosia);
• santonin (citrus wormwood);
• thymol (thyme);
• Pelotierin (pomegranate root);
• carvacrol (oregano, thyme, bergamot);
• diospirol (persimmon);
• arecoline (arec palm);
• pyrethrins (Dalmatian chamomile);
• tremulacin (poplar);
• nicotine (tobacco) and its anabazine isomer (tobacco and leafless corral);
• emetine (emetic root).

And today, a considerable proportion of anthelmintic medicines contain the same active substances that once provided the anthelmintic effect to decoctions and tinctures.

conclusions

• Helminthiasis is one of the most common diseases in the world. Anyone in your 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, then the disease may be asymptomatic for many years without manifesting at all.
• Even a regular medical checkup every 3 years or having a checkup once a year does not guarantee that a person really does not have helminths.
• The signs of worms in the body can be very similar to the symptoms of other illnesses. So if treating bowel diseases and other similar conditions for some reason persistently doesn't help, you should consider testing for helminths.
• According to the results of an analysis for helminths, a diagnosis of helminthiasis is not made, as both false-positive and false-negative results are possible. You shouldn't try to do an examination independently and randomly - it's better to consult a doctor: based on all symptoms, nutritional data and travel data, he will select tests that will let you know exactly whether a person has helminths or not.
• You cannot prescribe helminth pills independently. A remedy for worms may have contraindications for a specific patient and cause serious harm if used incorrectly.