Parasites - who is the host in the body?

Parasites are organisms that exist and provide for their needs at the expense of the host and cause diseases and conditions in it.

Parasitic invasions have long been known and, despite advances in medicine, are common in humans and animals today. Almost every person has suffered from a parasitic disease at least once in their life (especially in childhood).

Ascaris - a parasitic tapeworm

Much of the chronic disease of various organs and systems, including allergic reactions and autoimmune processes that can be triggered by parasites, is associated with the widespread spread of parasitoses.

There can be a wide variety of parasites - they can be microscopic and can reach a length of 10-14 m. Their lifestyle and the following qualities unite them:

  • High reproductive capacity.
  • Distribution and adaptation mechanisms in the host, whether human or animal, are continually improved.

What are parasites?

  1. The simplest parasites are unicellular.
  2. Helminths are multicellular parasites, including worms:
    • flatworms (liver, felines and other mites);
    • tapeworms (pinworm, tapeworm, whipworm, etc. );
    • tapeworms (bovine, porcine and dwarf tapeworms, broad tapeworms, etc. ).
  3. Arthropods are parasites belonging to ectoparasites characterized by an external chitin skeleton, segmental body, and limbs.

Terrible simplicity and unattractive appearance

Many unicellular organisms cause diseases that affect both humans and animals. The simplest parasites are: amoeba, leishmania, giardia, plasmodia, toxoplasma. Among them, the most common pathogen causing parasite invasion is Giardia. Doctors' opinion of this unicellular remains twofold. Some consider Giardia to be completely harmless, others blame it on many, if not all, of the host’s diseases.

There are also protozoa that, when introduced into the body, do not cause sluggish parasitic invasions, but life-threatening diseases such as malaria and leishmaniasis.

The designation 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 with and does not tolerate any disease, its mere presence in the body can cause discomfort to the patient. They do not in themselves cause significant damage to the body.

Male and female human nematodes

In addition, we will talk mostly about intestinal worms, as there is a lot of discussion about their timely detection in the body and the treatment of this particular group of parasites, advertisements for helminthic invasions that encourage people to find possibly non-existent symptoms and diseases.

A parasite, a farmer?

The parasite may have one or more hosts. In the latter case, one of the intermediates is an animal or a person in whose body there is an intermediate stage of development of the parasite associated with asexual reproduction. For many parasite species, the presence of an intermediate host is essential for survival.

The macro-organism in which the final stage of development of the parasite - the stage of sexual reproduction - takes place is called final.

Biohelm samples, in order to go through their entire developmental cycle, are forced to visit a variety of organisms, and some worms do not undergo any change in the body of the intermediate host — these are called geohelms.

How to be sick?

The infection can occur in several ways. This can be the ingestion of the parasite's reproductive material (cysts, eggs, larvae) due to the consumption of contaminated food or water, as well as violations of hygiene measures - from dirty hands, close contact with pets. (children often suffer from this). Less commonly, you can get a parasitic disease if you inhale the pest's eggs or cysts with dust. Wormworms include those whose larvae can penetrate the skin or animal directly through the skin, such as hookworms, the pathogens of ankylostomiasis, which can become infected when walking barefoot.

Parasites can enter the human body through a number of routes.

The spread of parasitic infections is facilitated by both climatic and social factors, including poor public health and hygiene education, violations of the health processing of certain products, and eating habits. For example, where the consumption of meat from domestic or wild animals that has not undergone health and veterinary inspections is widespread, the incidence of trichinosis remains high.

Habitats in the host

Parasites affect almost all organs and tissues. It all depends on what conditions are necessary for survival at a certain stage of the life cycle. Depending on the localization, helminthiases are divided into tissues (extraintestinal) and luminal (intestinal).

The former include trichinosis, toxocariasis, echinococcosis. However, in the host, parasites enter the internal organs and this form is called visceral. And many pathogens are characterized by specific damage to a particular organ system or even a specific target organ.

For example, Toxocara geohelmans, pathogens of toxocariasis, affect the visual organs, especially in school-age children. At the same time, there is no significant change in the general condition, only a decrease in sharpness and loss of part of the field of view, strabismus. Such manifestations usually last for several months. An important feature is that only one eye is always involved. With competent and careful ophthalmic examination, it is possible to detect and determine the disease in time.

In the human body, helminths are a popular habitat for helminths.

Illuminated helminthiasis include trichuriasis, ascariasis, opisthorchiasis, fascioliasis, and others. These helminths are found in the lumen of the hollow organs.

For many worm species, the usual habitat is the digestive system, namely one of its classes.

So the whipworm is in the colon, the tapeworm in the upper part of the small intestine, and the dwarf tapeworm in the lower part.

What determines the nature of the disease?

  • How the parasite enters the host.
  • parasite population density.
  • The degree of adaptation to the human or animal body.
  • Host condition (strength of immunity, presence of concomitant pathology).

Manifestations of parasitic infections

At the onset of the disease, the reactions of the macroorganism result from the penetration of foreign antigens and the response of the immune system to them. In many cases, the patient reports an unmotivated fever that lasts for more than a week with periodic improvement. Depending on the location of the parasite in the body, other symptoms may occur, which may include loss of appetite, belching, nausea, abdominal pain, stool instability, diarrhea, jaundice of the sclera and skin, and discoloration of urine and feces. . If a pest is found in the lungs, manifestations reminiscent of bronchopneumonia or even bronchial asthma are possible. Convulsions, paresis, and paralysis are not uncommon on the nervous system.

Parasite under the microscope

In the chronic phase of parasite invasion, metabolic disorders often occur because the pathogen feeds at the expense of the host and utilizes its nutrients. Absorption in the gastrointestinal tract is often impaired in the animal or person concerned. The affected organism is exhausted, anemia, beriberi manifestations may appear.

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

Parasitosis may not cause acute symptoms, but with a slow, prolonged course, often with long-term compensation. And only when the defenses of the affected organism are exhausted do alarming symptoms appear.

Interaction with the organization concerned

Among other things, helminths have a predominant effect on the host's immune system, which means that the latter becomes more vulnerable to various infections, recovers later, and the course of the disease becomes more difficult than the host's immune system. healthy.

The effects of parasites on the child's body are particularly harmful. The children are nervous, capricious, sleep disturbed, and quickly exhausted. Both physical and mental development are delayed. Perhaps the onset of allergic diseases, the course of concomitant pathology is exacerbated.

Despite the severity of the condition, parasite invasion only leads to death in advanced cases, as the parasite is completely host-dependent and is likely to be fatal to the pest, resulting in a weakening of the affected animal or person. by the parasite, but was not killed.

Parasitic invasions must not manifest in any way or appear very brightly. Timely recognition and making a correct diagnosis can only be done for the doctor and the patient in tandem, these diseases can be very insidious.