Human protozoan parasites, despite their microscopic size, are one of the most dangerous microorganisms that can cause serious diseases.
General information about representatives of protozoa
The kingdom of protozoa has a large number of representatives (about 15 thousand species), many of which are human parasites.
Another name accepted in medicine and biology for this kingdom is unicellular organisms.
These creatures consist of a cell of a certain shape, some can modify it, the cell has organelles that maintain viability.Unicellular microorganisms have adapted to locomotion using cilia, flagella or pseudopodia.
Due to their small size and structural features, protozoa can live even in the most protected tissues of the body.Parasites from the protozoa kingdom are causative agents of diseases of varying severity, some of them can even lead to death.
The elimination of unicellular organisms is complicated by the fact that they are able to cover themselves with a protective shell (cyst) and wait out conditions unfavorable for their existence.
Classification of the simplest inhabitants of the human body
Single-celled parasites are divided into 4 classes, depending on cell structure and lifestyle.
Table “Classes and representatives of protozoan parasites”
| Class | Brief description | Representatives |
| Flagellates | The cells are oval in shape, have a flagellum to move, move forward with a rope, thus being able to penetrate deep into the liquid medium.Flagellated colonies can reach 10,000 individuals.Most species live in tropical and subtropical climates. | Leishmania, Giardia, Trichomonas, Trypanosoma. |
| Sardcodae (rhizopods) | Movements are performed using pseudopodia and have a variable body shape. | Dysenteric amoeba |
| Sporozoa | They get their name from the presence of a spore stage in their development.Located in tissues and cells, they can cause hepatitis or anemia. | Piroplasms, Babesia, Coccidia, Plasmodium falciparum. |
| Ciliates | Moves using cilia, can live attached or swim freely | Balantidium |
Depending on the location, single-celled parasites are divided into 2 types:
- endogenous (living in internal organs and systems);
- exogenous (choose the skin as the place of residence).
Human protozoan parasites can travel throughout the body and infect various organs and tissues.
What diseases are caused by flagellates and ciliates?
Class Flagellates
- Leishmaniasis causes cutaneous leishmaniasis (Pendinsky's ulcer) and visceral leishmaniasis, the former manifests itself as constantly decaying ulcers on the body and the latter causes inflammation and bleeding.Leishmania enters the body through warm-blooded animals or a mosquito bite and affects the skin, heart, kidneys, blood and bone marrow.
- Giardia, the causative agent of giardiasis, affects the mucosal tissues of the intestines or gallbladder.After the defeat, people begin to suffer from asthma, mental disorders (most often depression), and the skin becomes dry.Giardia is common in countries with warm climates.
- Trichomonas (depending on habitat - oral, intestinal and genital or urogenital) causes trichomoniasis.After infection, a person feels itching in the area of the reproductive system and pathological discharge from the genitals is observed.The greatest danger of this disease is the high risk of developing infertility.
- Trypanosoma causes African or American trypanosomiasis (the first is sleeping sickness, the second is Chags disease).It affects the lymph nodes (they enlarge), the cerebrospinal fluid, the blood and the spleen, which disrupts the functioning of the spleen and liver, the patient suffers from drowsiness and may die.
Ciliated class
Balantidia is the causative agent of balantidiasis, affecting the mucous membrane of the large intestine.A clear sign of the presence of this parasite is diarrhea accompanied by mucus and blood.This disease often ends in death.
What diseases are caused by rhizomes and sporozoans?
Sporozoan class
- The malaria plasmodium enters the blood and liver and causes malaria.Symptoms of the disease are fever, chills or fever, central nervous system disturbances, and death is possible.It is transmitted through the bites of malaria mosquitoes and is transmitted by humans.
- The causative agent of toxoplasmosis is toxoplasma, which affects the central nervous system, digestive organs, muscle tissues and eyes.At first, this occurs without symptoms, then disturbances in the functioning of certain organs are observed.
Class sard code
Dysenteric amoeba is the causative agent of amoebiasis, affecting the mucous membrane of the large intestine and, more rarely, the bladder and skin.It can be asymptomatic or present with vomiting, diarrhea mixed with blood and low fever (up to 37.5 degrees).Symptoms appear 7 to 10 days after the amoebae enter the body.
Extraintestinal forms of the disease, which affect the liver, lungs or other organs, are less common.This disease is common in Asian and tropical countries.
Routes of infection
Single-celled parasites enter our body in different ways: through the skin or through natural openings in the human body.
There are four main routes (routes) of human infection with parasitic disease:
- the contact-household route opens in cases of unsanitary conditions and non-compliance with the rules of personal hygiene (when shaking hands or using household items, bathing in dirty water, cysts enter the human body and begin to grow), trypanosomes and trichomonads are transmitted through this route;
- thanks to products contaminated by parasites (meat, particularly wild animals, fish, dairy products), they can be disinfected by heat treatment;an example of a disease transmitted in this way is toxoplasmosis;
- fecal-oral route: parasites leave the body with feces or vomit, then enter water, food, household items, the owner's hands, and through them into the body of a new carrier (this route of infection is especially common in children: contact with animals, eating unwashed fruits, playing in a dirty sandbox);
- communicable (malaria) – transmission of protozoan parasites through bites with the carrier's saliva.
Much less often, parasites enter the body in the following ways:
- from mother to fetus during pregnancy, this path is called transplacental, because parasites penetrate through the placenta;
- with contaminated blood (blood transfusion and other medical procedures, injections, including narcotics, during intimacy) - contact with blood;
- during sexual intercourse - sexual tract.
Infection prevention
To prevent infection with single-celled organisms, a person must follow a number of simple rules:
- proper heat treatment of fish and meat, milk control;
- You can only eat products that have passed health inspection;
- washing fruits before eating them and simply soaking them in water is not enough;you need to wash them thoroughly and, if possible, pour boiling water over them;
- avoiding casual sexual contact;
- prevention of insect bites (use of special creams, mosquito nets);
- regular medical examinations in case of suspected infection and for prevention purposes;
- increase immunity, especially through the consumption of garlic, oranges, carrots, green tea, dried fruits, rice porridge;
- basic knowledge of the protozoa that parasitize the human body and how they get there.
It is easy to follow these rules, the main thing is regularity.
Information on parasite groups, examples of single-celled parasites, helps to choose priority among the mentioned preventive measures.
With proper prevention and in case of illness - surgical treatment, parasites will not harm your body.