Parasites In The Human Body: Classification, Diagnosis

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Parasites In The Human Body: Classification, Diagnosis
Parasites In The Human Body: Classification, Diagnosis
Video: Parasites In The Human Body: Classification, Diagnosis
Video: Microbiology of Parasites 2023, February

Every modern person at least once in his life faced the problem of parasites in the body. The number and variety of parasites that, in the literal sense of the word, cannot live without us, is simply enormous. Parasites in the human body use it as a source of food and habitat until they completely deplete it, but at the same time do not betray their presence.

Parasites are microscopic in size or can grow up to several meters in length, but even then their vital activity in the body cannot always be felt. A person, as a rule, does not feel them and does not even know about their presence within himself. Meanwhile, they are able to live in a human body for years and even decades, thereby causing irreparable harm to it.


Parasites in the human body pose a serious danger and pose a great threat to human health, since they disrupt the work of internal organs and systems, provoke a malfunction of the immune system and interfere with the full absorption of nutrients, vitamins and trace elements. In some cases, the situation is so serious that it can even lead to death.


  1. Types of relationships between organisms
  2. Parasitism and parasites
  3. Parasite classification
  4. How parasites enter the human body
  5. Features of the device
  6. How to identify parasites in the body
  7. External and internal manifestations
  8. Diagnosis of parasites
  9. How to remove parasites from the human body

Types of relationships between organisms

In nature, there are several types of relationships between organisms, which have a variety of effects on each other.

The impact of one species on another can be either neutral or positive, or negative. In addition, there are various combinations of such relationships. Distinguish:

  • symbiosis;
  • neutralism;
  • antibiosis.

Symbiosis is a form of relationship between two organisms, from which both benefit.

Neutralism is a type of biological connection, which consists in the habitation of two organisms in the same territory, but at the same time they are not connected with each other and do not directly affect each other.

Antibiosis is an antagonistic type of biological relationship in which one type of population limits the capabilities of another, negatively affecting it. One of the most negative types of antibiosis is parasitism.

Parasitism and parasites

Parasitism is a form of antibiosis in which members of one species use the organism of another species as a temporary or permanent habitat and source of nutrients.

Biological organisms that live off another organism are called parasites.

Parasites do not kill their host, but for a long time use it as a source of food and habitat. Parasites include:

  • parasitic worms;
  • pathogenic bacteria;
  • protozoa;
  • mushrooms;
  • viruses.

Host organisms can be:

  • bacteria;
  • protozoa;
  • plants;
  • animals;
  • person.

In the process of development, parasites go through several stages of development from eggs and larvae to an adult (mature, invasive), which indicates their longevity and the need to change 2–3 hosts.


Parasite classification

All parasites are divided into obligate and optional.

Obligate parasites either die outside the host's body or exist in an inactive state. For example: viruses. They lead an exclusively parasitic lifestyle, that is, they are completely dependent on the host and activate their activities inside it.

Facultative parasites lead a parasitic lifestyle, but if necessary, they can exist in an absolutely normal form in the external environment. For example: pathogenic fungi and bacteria.

By the nature of the relationship with the host organism, they are divided:

  • true parasites;
  • false parasites;
  • superparasites.

True parasites are the same obligate parasites for which the parasitic lifestyle is the only form of survival. However, there are parasites that can be both obligate (permanent) and optional (temporary). For example: lice, fleas, intestinal worms.

False parasites are freely living organisms that, if accidentally ingested, are able to live in it for some time and harm it. For example: house fly larvae in human intestines.

Superparasites are parasites that live in other parasites. For example: bacteria and viruses in other parasitic insects that live in other organisms.

Depending on the duration of interaction with the host organism, there are:

  • persistent parasites;
  • temporary parasites.

Permanent parasites are organisms that spend their entire life cycle in the host organism, depositing larvae in it. For example: roundworms, tapeworms, lice.

Temporary parasites live and feed on the host at a certain stage of development. For example: larvae in wolf fly and adults (adult insects) in fleas and mosquitoes.

According to their location in the host's body, parasites are divided into:

  • ectoparasites;
  • endoparasites.

Ectoparasites are organisms that live on the skin of the host. For example: lice, fleas, ticks.

Endoparasites are organisms that reside inside the host's body. Endoparasites are divided into:

  • intracavitary parasites;
  • tissue parasites;
  • intracellular.

Intracavitary parasites are organisms that are located in cavities that connect with the external environment, for example: ascaris, whipworm in the human intestine.

Tissue parasites are a type of organisms that are located in closed cavities and tissues of the host organism, for example: for example, liver flukes, cysticercus of tapeworms.

Intracellular parasites are localized in the cells of the host organism, for example: malaria plasmodia, toxoplasma.


By distribution in the environment, parasites are:

  • ubiquitous, ubiquitous;
  • tropical, which are only common in hot, tropical climates.

According to biological and epidemiological characteristics, parasites are divided into:

  • geohelminths are parasites that go through the initial stage of development in the human body, and then in the external environment (for example, the earth);
  • biohelminths are parasites in which the development cycle takes place not only in the human body, but also in the organisms of other creatures. The person is usually the final owner, and sometimes the intermediate.
  • contact helminths are released from the host organism as mature or semi-mature, as a result of which its re-infection or infection of another person is possible (autoinvasion, reinvasion).

How parasites enter the human body

There are many favorable factors that contribute to the entry of parasites into the human body:

  • dirty hands;
  • animal hair;
  • poorly prepared foods (nutritional factor);
  • contact and household factor;
  • transmissible;
  • percutaneous.

Dirty hands are the main source of parasitic infection. There are a number of diseases called dirty hand diseases. The larvae of worms, first on the skin of the hands, and then in the mouth, cause characteristic symptoms from the gastrointestinal tract. The route of transmission of these infections is called fecal-oral. Thus, helminths enter our body during contact helminthiasis. For example, ascaris eggs enter the human body through dirty hands, poorly washed vegetables, fruits, berries, herbs, and are also carried by flies.


Animals and their fur are a source of infection with ascaris and lamblia worms. For example, pinworm eggs that have fallen from the fur of an animal remain viable for a long time (up to about 6 months) and, once on carpets, things, bedding, children's toys and hands, penetrate the food tract.

Also, through wet breath, dogs and cats are able to disperse the eggs of parasites at a distance of 3 - 5 meters. In addition, fleas exist on the fur of dogs and cats, which also carry the eggs of worms.

The alimentary method of infection with parasites is carried out:

  • through poorly washed vegetables and fruits;
  • poorly cooked food (most often meat);
  • contaminated water.

For example, improperly cooked shish kebab, jerky or homemade bacon can infect a person with trichinosis and echinococcus, and poorly cooked dry fish or caviar can cause infection with opisthorchiasis and broad tapeworm.

The transmission method of infection occurs with the help of blood-sucking insects, for example: ticks, mosquitoes, lice, fleas, bedbugs.

The contact - household route of infection is carried out through an infected person or animal, through contact or when using common household items.

Percutaneous infection occurs while swimming in water bodies or contact with contaminated soil. The larvae enter the body through mucous membranes or human skin through contact with water or contaminated soil.

Features of the device

Almost all parasites are highly adaptable to survival. There are a number of factors that contribute to their high resilience:

  1. Long life expectancy. For example, helminths live in the human body for years, and sometimes just as long as the owner himself lives.
  2. Helminth eggs are able to survive for decades and not be destroyed in the external environment.
  3. The stage of development of the parasite also contributes to its lifespan. It goes through all stages of development, starting with the egg, continuing with the larva and changing the host, in case of a lack of nutrients.
  4. The ability of parasites to induce a state of immunodeficiency in the host, which allows pathogenic agents to penetrate from the outside, as well as "kindle" dormant internal infections.
  5. Helminths that enter the human gastrointestinal tract produce antienzymes, which allows them to escape their own death, but at the same time they disrupt the normal process of digestion and cause toxic and allergic reactions in their host: asthma, urticaria, dermatitis.
  6. The invulnerability of parasites is associated with the exchange of genetic information during sexual reproduction, which leads to the stability of their heterogeneous population.
  7. Wide vitality of helminths in many habitats: soil, water, animals, plants.
  8. Lack of effective methods of immunoprophylaxis, since parasites are capable of suppressing or modifying the immune response of the host organism.

How to identify parasites in the body

As a rule, a person asks such a question when his health is thoroughly undermined. It is common for a person to dismiss a problem at its initial stage until it develops into a serious form and affects his well-being.


Since parasites are divided according to their habitat in the body - the host into endoparasites and ectoparasites, the symptoms are divided into internal and external.

Ectoparasites are characterized by certain activities, which are manifested by the following symptoms:

  • skin rashes;
  • itching;
  • burning sensation;
  • hyperemia;
  • pain (if it was a bite);
  • the presence of a wound at the site of the bite.

Finding endoparasites is much easier. To do this, carry out the following actions:

  • visual identification (if there was penetration from the outside through the skin);
  • microscopic examination.

Detection of ectoparasites is a difficult task, because in the process of evolution, "dependents" have perfectly adapted to survival, while disguising themselves and not giving themselves away, they carry out destructive work in the host's body. After all, a person lives, for example, with worms from the time of the appearance of his species, and the stages in their development can take from several months to ten years. So how to determine the presence of parasites in the body?

External and internal manifestations

Since parasites have a long life span and actively multiply in the human body, they cause symptoms that are long-term, recurrent and chronic. The external manifestations of the activity of parasites include:

  • skin rash;
  • itching;
  • burning;
  • hyperemia;
  • feverish condition;
  • Quincke's edema.

It is important to know that the degree of allergy development depends on many factors:

  • the location of the parasite in the body;
  • contact of the parasite with tissues and vital organs;
  • the amount of toxins produced.

Disorders in the body during internal invasion include the following symptoms:

  • disturbances in the work of the gastrointestinal tract (nausea, diarrhea, belching);
  • weight fluctuations associated with lack of nutrients and decreased appetite;
  • craving for sweets due to metabolic disorders and general weakening of the body;
  • chronic fatigue syndrome, which is manifested by general fatigue, drowsiness, in some cases insomnia, impaired concentration and memory;
  • persistent headaches caused by weakness and intoxication;
  • teeth grinding in sleep (bruxism), especially in children;
  • swelling of the limbs;
  • nervous disorders and psycho-emotional disorders, since parasites can cause depression and irritability;
  • paroxysmal cough;
  • pain in muscles and joints;
  • painful pallor of the skin;
  • skin lesions (dermatitis, eczema, acne and acne).

It is especially important to know the general symptoms that are observed with intestinal parasitic invasion:

Disorders in the digestive tract, which are manifested by the following symptoms:

  • intestinal spasms;
  • irritable bowel syndrome;
  • flatulence;
  • constipation or diarrhea;
  • discoloration of feces;
  • itching in the anus;
  • visual detection of helminths;
  • the presence of worms in the vomit.

Since worms can reach significant sizes in the body, they can physically hinder the movement of feces and disrupt the work of other organs, for example, the bile ducts.

Parasites can cause disturbances in the functioning of a specific organ or system.


The most common violations are:

  1. Anemia.
  2. Lesions of the central nervous system.
  3. Liver abscesses.
  4. Purulent inflammation of the gallbladder and pancreas.
  5. Immunity malfunctions, up to the development of autoimmune reactions.
  6. Disturbances in the respiratory system.
  7. Diseases of the joints.

Diagnosis of parasites

All of the above symptoms cannot always accurately confirm the presence of parasites in the body, since this symptomatology can be observed in many diseases.

You can establish the presence of parasites in the human body by examining feces. However, this method is also unreliable, because the larvae of the parasite cannot always be seen through a microscope or skipped. In addition, not all parasites lay many eggs.

In order to detect the larvae of parasites in feces, it is necessary to take up to 8-10 times the analysis of feces. But if in this case the analysis did not show anything, and the doctor still had doubts, then a number of serological blood tests are prescribed, which will help identify helminth antibodies that appear in the blood within a few weeks after infection with parasites.

There are other methods of identifying "dependents", the so-called string test. A string with a capsule is inserted through the nose into the patient's intestine and removed after four hours along with the samples obtained.

Another method is colonoscopy, during which a specialist examines the condition of the inner surface of the colon using a special probe.

Experts have found that the most common parasites are helminths. In addition, they are all very hardy and fertile, and their goal is to destroy their master and extract the maximum benefit for themselves.


How to remove parasites from the human body

Getting rid of parasites is difficult, but possible. It is important to prioritize: it is necessary not only to know how to get rid of parasites, but also to understand what the treatment process itself is. It is carried out in three directions:

  1. Destruction of parasites at all stages of existence. That is, it is necessary to destroy not only adults, but also the larvae and their eggs.
  2. Normalization of the work of all organs and systems of the body.
  3. Recovery of the body.

Modern preparations based on herbal ingredients will help to satisfy all three of the above points:

  • "Metosept +";
  • "Regesol";
  • "Imkap";
  • "Fomidan";
  • "Vitanorm +";
  • "Maxipham +";
  • "Neuronorm";
  • "Baktrum".

All these drugs are modern drugs of the last generation and have a certain therapeutic effect. The use of these drugs in a complex allows you to combine their therapeutic effect and get a wonderful result.

Dosage and combination of drugs with each other is carried out on the basis of:

  • stages of parasitic invasion;
  • the general condition of the patient;
  • the presence of complications from a specific organ;
  • the severity of the disease.

The priority of anthelmintic drugs is based on:

  • efficiency;
  • security;
  • the possibility of combining several drugs for the best therapeutic effect.

Treatment with folk remedies is a very effective way to get rid of parasites. The most commonly used herbal cleansing tea, which neutralizes the harmful effects of parasites, cleanses the liver and gallbladder.

Tea is prepared as follows: take one tablespoon of the following plants: oak bark, buckthorn, wormwood, tansy. Then one tablespoon of the herbal mixture is poured with 500 ml of boiling water and left in a sealed container overnight. In the morning on an empty stomach, drink 100 g of the resulting tincture. Treatment continues for two to three weeks.

Pumpkin seeds are also very effective in fighting parasites. To get rid of parasites, they take 300 grams of pumpkin seeds, peel them, but at the same time leave as much transparent film as possible that envelops the seeds. Seeds should be eaten in the morning on an empty stomach. This recipe not only eliminates parasites, but also improves the functioning of the intestines, stomach, liver and gallbladder.

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