Among the dangerous organisms that settle inside a person and harm his he alth, a significant place is occupied by parasitic protozoa. These are single-celled animals that have adapted to existence at the expense of others. They are quite numerous, in total there are about 30 different types of individuals that specialize specifically in humans. More common in other vertebrates and invertebrates.
Parasitic protozoa: structural features
Externally and internally, these organisms have exactly the same structure as all other unicellular organisms. They have only one structural unit, but it is able to perform all the vital functions necessary for normal life. Namely:
- grows and develops;
- reproducing;
- eating;
- breathes;
- has excitability and irritability;
- moving.
Therefore, we can say with confidence that parasitic protozoa are completely independent, integral living organisms. What makes them different from everyone elseunicellular in that they have lost the digestive vacuole due to a parasitic way of life, as well as the contractile one. In addition, most often deprived of the organelles of movement.
Reproduce quite quickly, asexually. The mother cell simply, upon reaching maturation, breaks up into several daughter cells. They lead independent lives immediately after education.
How do parasites feed in the host organism? It depends on the individual characteristics of each species, but basically their food is blood or intestinal contents. They absorb substances with the entire surface of the body due to the reduction of the vacuole.
Classification and representatives of simple parasites
The various representatives of the organisms under consideration can be classified as follows.
| Class | Representatives |
| Sporozoans | malarial plasmodium, coccidia, gregarines, piroplasmids |
| Roots | dysenteric amoeba, intestinal, oral amoeba |
| Flagellates | Trichomonas, Giardia, Trypanosomes, Leishmania |
| Ciliates | balantidia |
All these organisms are the cause of human protozoan diseases. All of them are parasitic protozoa that are very dangerous for life and he alth. The table includes only the most common representatives. In fact, there are more rare ones, there are quite a lot of them.
Leishmania
Today, the figure reflecting the number of people affected by this parasite is simply terrible - 12 million. This oval-shaped immobile intracellular representative of the protozoa has a small flagellum. However, it moves very slowly and over short distances.
Settling inside the cells of the host, which for Leishmania is an insect and a mammal, including humans, they cause a gradual death of the structure. In humans, on the skin, in the place where Leishmania lives, an open gaping ulcer is formed, constantly festering. This disease is called rubber or Baghdad ulcer. It is treated very difficult and long, with surgical intervention.
The single-celled mosquitoes carry this group, so foci of leishmaniasis are found in the countries of the tropics and subtropics.
Giardia
Class of parasitic protozoa, which include Giardia - Flagella. The most dangerous representative for people is intestinal giardia, which causes a dangerous disease - giardiasis.
Adults parasitize in the upper intestine. It is here that they absorb all the nutrients that a person consumes by pinocytosis. Also, this organism is able to form cysts. In this state, they can survive ultraviolet radiation and exposure to toxic substances. However, low and high temperatures are deadly for them.
Cysts are located in the large intestine, so they are excreted with solid waste products. They are infected throughmud, water. Therefore, the rules of personal hygiene are especially important in the prevention of giardiasis.
How dangerous is this parasite? In the process of life, Giardia releases toxic decay products that strongly poison the body from the inside.
Parasitic rhizomes
This class includes different types of amoeba:
- intestinal;
- dysentery;
- oral.
These parasitic protozoa cause dangerous diseases in humans, which in some cases can even end in death.
Dysentery amoeba is a representative of hot countries. It is in them that she is the most common parasite. Its feature, like all amoeboids, is the absence of shell and skeletal formations. Therefore, she moves with the help of false legs. Reproduces by simple division. It is able to form cysts, also living in the human body. Multiple division occurs within this structure.
Causes the disease amoebiasis. The inner walls of the intestines are affected, on which amoebas leave bleeding ulcers. A person has bloody loose stools, pains inside the body. Diagnosing dysenteric amoeba is difficult. Therefore, she is a very dangerous representative of parasites.
Unlike the considered form, the intestinal amoeba is present in the body of almost every person and lives with him in harmony. Does not emit toxic substances and does not perforate the intestinal walls. Therefore, special discomfort anddoes no harm to he alth.
The oral amoeba is an inhabitant of plaque and caries formations. It feeds on bacteria, can consume red blood cells. Its exact meaning for humans is not yet clear.
Balantidia coli
This organism is a representative of the Ciliates class. A rather large oval unicellular organism that settles in the intestines of people. It is here that he masters and perforates the wall of the organ, causing the occurrence of bleeding, festering wounds. Cysts of this protozoan easily enter the bloodstream. This is how settlement occurs throughout the body.
How do parasites of this species feed? Exactly the same as other representatives. They absorb nutrients in the human intestines by the entire surface of the body. It reproduces by asexual division into several cells. Forms cysts, which also parasitize in humans.
Infection with protozoan cysts occurs when mucous membranes come into contact with dirty hands, when drinking raw water. The disease caused by these creatures is called balantidiasis. Accompanied by vomiting with blood, diarrhea, weakness, severe colic in the abdominal cavity.
Trichomonas
Parasitic protozoa that live in the genitourinary system of women and men. By themselves, they may not cause harm, but they are a hiding place for pathogenic bacteria and other pathogenic organisms. They are able to disguise themselves as human cells, so the immune system itself is not capable of destroying them.
The disease thatcauses directly trichomonas, called trichomoniasis. It is sexually transmitted and threatens infertility for both men and women.
Signs of disease in children
The worst thing is when parasites appear in children. Symptoms of their occurrence are as follows:
- general weakness;
- fatigue;
- pallor;
- headaches;
- loss of appetite;
- bad dream;
- irritability;
- liquid stool;
- vomiting and others.
The most important thing is to pay attention to them and not let everything take its course. Moreover, according to the latest data, parasites in children are in the first place among diseases. Symptoms are a sure sign that you should think about it and see a doctor.
