Parasites - who is the host in the body?

Parasites are organisms that survive and supply their needs at the host's expense and cause diseases and conditions in the host.

Parasite invasions have been known for a long time and despite advances in medicine, are still common among humans and animals today. Almost every person, at least once in their life (especially in childhood) gets a parasitic disease.

Roundworm - parasitic roundworm

A large proportion of chronic diseases of various organs and systems, including allergic reactions and autoimmune processes, which can be caused by parasites, are associated with the wide spread ofparasites.

Among the parasites, there are many species - they can be both extremely small and reach a length of 10-14 m. They are united by lifestyle as well as the following characteristics:

  • High fertility.
  • Constantly perfecting the mechanism of distribution and adaptation to live in the host, human or animal body.

What is a parasite?

  1. The simplest parasites are single-celled organisms.
  2. Helminths are multicellular parasites, including worms:
    • flatworms (liver, cat and other flukes);
    • roundworms (pinworms, roundworms, roundworms, . . . );
    • tapeworms (beef, pig and pig tapeworms, broad tapeworms, etc. ).
  3. Arthropods are ectoparasites, which are characterized by an exoskeleton, segmented body, and limbs.

Terrible simplicity and unattractive appearance

Many protozoa cause diseases that affect both humans and animals. The simplest parasites include: amoeba, leishmania, giardia, plasmodia, toxoplasma. Among them, the most common parasitic invasive pathogen is Giardia. The opinion of doctors about this single cell remains twofold. Some consider Giardia completely harmless, others blame them for many, if not all, diseases of the host organism.

There are also protozoa that, once entered the body, do not cause slow parasitic invasions, but life-threatening diseases such as malaria, leishmaniasis.

The definition of lice, ticks and fleas as ectoparasites of animals and humans is due to the fact that they are on the surface of the skin. If the pathogen is not infected and does not tolerate it, just being present on the patient's body can cause inconvenience to the patient. By themselves, they do not cause significant harm to the body.

Roundworm men and women

Furthermore, we will talk most about helminths, since there is a lot of controversy about their timely detection in the body and how to treat this particular group of parasites, which are concerned with invasions of the worms. helminths are promoted by advertising that encourages people to search and find symptoms and diseases that may not exist.

A parasite, a host?

Parasites can have one or more hosts. In the second case, one of them is an intermediate - an animal or person in the body where the intermediate stage of development of the parasite takes place, which is involved in asexual reproduction. For many species of parasites, the presence of an intermediate host is essential for survival.

Macrobiotics take place in the final stage of development of the parasite - the stage of sexual reproduction, which is called the terminal stage.

Biological helminths, in order to go through their entire development cycle, they are forced to visit multi-species organisms, and some helminth species do not undergo any changes in the body of the intermediate host- they are called helminths.

How can you get sick?

Infections can occur in many different ways. This can be due to ingestion of parasite reproductive material (cysts, eggs, larvae) by ingestion of contaminated food or water, and also by violation of hygiene measures - by dirty hands. , close contact with pets (children often suffer from this). Less commonly, you can get parasitic disease from breathing in the dust or eggs of the pest. Among the helminths there are those whose larvae can enter the body of animals or humans directly through the skin, such as hookworms, the causative agent of strongyloidiasis, which can be infected during travel. bare feet.

There are many routes by which parasites can enter the human body.

The spread of parasitic infections is facilitated by both climatic and social factors, including poor hygiene education levels of the population, violations in hygienic processing of certain products, and poor hygiene practices. products, as well as eating habits. For example, in places where the consumption of wild or animal meat that has not undergone sanitary and veterinary control is common, high levels of trichiasis persist.

The environment in the host's body

The parasite affects most organs and tissues. It all depends on what conditions are needed to survive at a certain stage of the life cycle. Depending on the local area, helminths are divided into tissue (gastrointestinal tract) and intestinal (intestinal tract).

The former includes trichinosis, toxocariasis, echinococcosis. At the same time, in the host body, the parasites are introduced into the internal organs, and this form will be called viscera. And also for many pathogens, specific damage to a particular organ system or even a particular target organ is characteristic.

For example, the worm Toxocara, the causative agent of toxocariasis, affects the organ of vision, especially in school-age children. At the same time, there is no significant change in the general condition, only a decrease in visual acuity and partial loss of visual field, it is possible to develop strabismus. Such manifestations usually develop over several months. An important feature is that only one eye is always affected. With a competent and careful ophthalmological examination, timely detection and identification of the disease is quite possible.

The common habitat of helminths in the human body is the intestinal tract.

Types of glowworms include gnathostomiasis, roundworms, eyeworms, fascioliasis, and others. These helminths are located in the lumen of hollow organs.

For many species of helminths, the usual habitat is the digestive system, specifically one of its parts.

Thus, flagellates live in the large intestine, roundworms live in the upper part of the thin intestine, and dwarf tapeworms live in the lower part of it.

What determines the nature of the development of the disease?

  • How the parasite enters the host's body.
  • parasitic population density.
  • The degree of adaptation to the human or animal body.
  • The state of the host organism (strength of immunity, presence of concomitant pathology).

Manifestations of parasitic infection

In the early stages of the disease, microbial reactions are due to the entry of foreign antigens and the immune system's response to them. According to the patient, in many cases, fever without cause occurs, which can persist for more than a week if the condition improves periodically. Depending on the location of the parasite in the body, other symptoms will appear, including loss of appetite, belching, nausea, abdominal pain, unstable stools, diarrhea, yellowing of the dura and skin, discoloration of urine and stools . When a pest is detected in the lungs, symptoms resembling bronchopneumonia or even bronchial asthma can occur. From the side of the nervous system, convulsions, paralysis, paralysis are not uncommon.

Parasites under the microscope

In the chronic phase of parasite infestation, metabolic disturbances often manifest themselves, as the pathogen feeds on the host and utilizes its nutrients. Absorption in the digestive system is usually impaired in affected animals or humans. Affected organisms are depleted, anemic, and may show signs of beriberi.

In addition, the pathogen poisons the macroorganism with the products of its vital activity, causing symptoms of intoxication in the host.

Parasitic diseases may not cause acute symptoms, but have a slow, prolonged course, often requiring long-term compensation. And only when the defenses of the affected organ are exhausted do alarming symptoms appear.

Interaction with the affected organism

Helminths, among other things, have a strong effect on the host organism's immune system, which means that the latter becomes more vulnerable to various infections, its recoverywill come later and the course of the disease will be more difficult than in a healthy person.

The effect of parasites on the child's body is especially detrimental. Children become stressed, erratic, sleep disturbed, quickly exhausted. Both physical and mental development are slowed down. Perhaps the emergence of allergic diseases, the pathological process is simultaneously aggravated.

Although the condition is serious, the infestation of the parasite only leads to death in severe cases, since the parasite is completely dependent on the host, death to the pest organism is potentially fatal. mortality is high, so the organs of the affected animal or person are weakened by the parasite, but not killed.

Parasitic invasions may not manifest in any way or manifest very brightly. Timely understanding and establishing an accurate diagnosis is a task that is only possible for the parallelism of doctor and patient, these diseases can be very insidious.