Digenetic Flukes: Structure, General Characteristics And Methods Of Treatment

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Digenetic Flukes: Structure, General Characteristics And Methods Of Treatment
Digenetic Flukes: Structure, General Characteristics And Methods Of Treatment

Video: Digenetic Flukes: Structure, General Characteristics And Methods Of Treatment

Video: Digenetic Flukes: Structure, General Characteristics And Methods Of Treatment
Video: Helminths: Cestodes and Trematodes (transmission, clinical importance, and treatment) 2024, March
Anonim

Page content

  • Structure and appearance
  • Habitat and life cycle
  • Ways of infection in humans
  • Symptoms and manifestations
  • Treatment methods
  • You can defeat parasites!

Digenetic flukes are a type of flatworms (helminths), about 40 species of which are included in the class of flukes (flukes) and cause parasitic diseases in humans. Depending on their localization in the human body, they are subdivided into hepatic, blood, pulmonary flukes and trematodes localized in the small intestine.

Structure and appearance

The structure of these parasites has its own characteristics due to their lifestyle. Most of these helminths are leaf-shaped, which in some species approaches rounded (see photo).

What to do in such a situation? To get started, we recommend reading this article. This article details the methods of dealing with parasites. We also recommend contacting a specialist. Read the article >>>

The body of the helminth, located in the musculocutaneous bag, is equipped with two suction cups: an oral one at the front end and an abdominal one closer to the center, which allow the worm to be securely fixed in place of localization.

Interestingly, the presence of two suckers gave reason to call these helminths flukes, since initially it was mistakenly believed that both of them lead to the mouth.

Cuticular spines, located on the upper layer of the epithelium, serve as an additional means of anchoring in the host's body.

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The structure and appearance of representatives on the example of an echinococcus tapeworm

The body of the flukes themselves is a combination of several systems:

  • the digestive system, consisting of the mouth, pharynx, esophagus and two "blind" intestinal canals; waste goes out through the mouth because there is no anus; the main supplier of energy for trematodes is glycogen, the reserves of which can be up to 60-65% of their body weight;
  • the excretory system, which consists of the thinnest tubes leading from the cells, which are grouped into larger tubules, and these, in turn, into the collecting ducts, reaching the passage at the back of the body of the worm;
  • nervous system, consisting of a nerve node with lateral branches in the form of paired pillars, located on the peritoneum, back and sides, and between the latter there is a bond. At the larval stage, the receptors of the epithelium and the eyes perform the function of peculiar sense organs;
  • reproductive system, the structural features of which are unique. Trematodes are hermaphrodites and have genitals that are common to both sexes. However, in the blood of mammals, and therefore of humans, a rather small female is placed by a larger male in a kind of pocket in the fold of his body, where she is not only held throughout her life, but also produces thousands of eggs.

The eggs of trematodes, covered with a dense impermeable shell, have an oval, sometimes irregular shape with a cap at the end - when it is time for the larva to hatch, the cap swings open and releases it outside.

Some of these helminths may have spines or processes on the egg. Eggs can vary in color from yellowish to dark brown, almost black.

It is interesting that in the eggs of many species of trematodes, embryonic development begins already while in the uterus, and therefore the egg that has entered the external environment contains an already formed larva, which is quite ready for independent existence.

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It looks like fluke eggs

Habitat and life cycle

Trematodes are most commonly found in Africa, the Middle East, Latin America (including the Caribbean), China, and East Asia. In Russia, they are registered in the Ob-Irtysh and Amur basins.

The life cycle includes several stages:

  1. The eggs are laid by the female in the body of the definitive (final) host, from where they go out into the external environment with feces, urine or sputum. Miraditsii (first larval stage), located in the egg, is either swallowed by the first intermediate host, or hatches independently and moves with the help of cilia.
  2. The first intermediate host (most often a mollusk) swallows the egg. Further in its body, the larva either leaves the egg, or, depending on the species, continues its development and enters the sporocyst stage (second larval stage).
  3. Thanks to special cells, a redium (third larval stage) is formed from it, and from it - a cercarium (fourth larval stage), the structure of which practically corresponds to adults.
  4. Cercariae leave the intermediate host, piercing its body with a sharp thorn located on the tail, and start free swimming in search of the next host. Some of them attach to aquatic plants, forming adolescaria; some penetrate under the skin of the inhabitants of the reservoir (fish, crayfish, waterfowl, etc.) and wait for absorption by the final host, man or animal, where they turn into an adult - marita, provoking the development of trematodes.

Ways of infection in humans

It should be noted right away that there are several options for infection with trematodes:

  • consumption of contaminated meat and fish that have not undergone proper heat treatment;
  • bathing in contaminated water bodies, where cercariae can enter the body through disturbed skin (abrasions, scratches, cracks, etc.);
  • upon contact with algae or other objects in the water, on which adolescaria are fixed;
  • when using kitchen utensils (knives, cutting boards, etc.), on which previously infected fish or meat was cut.
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Most often, parasites enter the body as a result of eating contaminated meat or fish

Symptoms and manifestations

Take a test for the presence of a parasite in the body

Symptoms Answer Temperature increase Yes Not Weakness Yes Not Diarrhea with blood Yes Not Drastic weight loss Yes Not Diarrhea and vomiting Yes Not Seizures Yes Not Feeling of choking and insomnia Yes Not Enlarged liver Yes Not The appearance of seals in the abdominal cavity Yes Not Convulsions up to epileptic seizures Yes Not

Different types of flukes cause different types of trematodes, which are usually accompanied by skin rashes and itching, eosinophilia, abdominal pain and nausea.

However, similar symptoms are found in many diseases, so it is necessary to very carefully record all manifestations of the disease. Their specific characteristics are especially important here.

Infection with blood flukes is accompanied by:

  • an increase in temperature;
  • severe sweating, feeling of weakness;
  • diarrhea, often with blood;
  • weight loss that cannot be explained;
  • constant coughing.

Infection with pulmonary trematodes is accompanied by:

  • diarrhea and vomiting;
  • fever with chills and intense sweating;
  • headaches;
  • convulsive attacks.

Infection with hepatic trematodes is accompanied by:

  • an increase in body temperature;
  • a feeling of suffocation and insomnia;
  • enlargement of the liver.

Infection with intestinal flukes is accompanied by:

  • diarrhea;
  • the appearance of seals in the abdominal cavity;
  • bleeding (in some cases);
  • convulsions up to epileptic seizures.

Treatment methods

Before starting the treatment of trematodes, it is necessary to carry out a differential diagnosis in order to know which digenetic flukes have affected the body. Along with the collection of anamnesis, laboratory tests of blood (including biochemical), feces, urine, and sometimes sputum, in which eggs may be found, are carried out.

If an infection with a pulmonary fluke is suspected, an X-ray examination is prescribed, with other types - an ultrasound of the abdominal cavity.

The general characteristics of therapeutic tactics are as follows:

  • preparation is carried out first;
  • then directly a course of therapy;
  • treatment is completed with a recovery course.

Modern medicine has a rich arsenal of anthelmintic drugs, but only a doctor should prescribe them after determining the type of trematode.

Self-medication will not only be ineffective, but can also lead to very serious consequences, since almost all such drugs are quite toxic. Traditional medicine should be used not as an alternative, but as an adjunct to drug treatment.

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