Human protozoan parasites, despite their microscopic size, are one of the most dangerous microorganisms that can cause serious illnesses.
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 for this kingdom, accepted in medicine and biology, is unicellular organisms.
These creatures consist of a cell of a certain shape, some can change it, the cell has organelles that maintain viability.Single-celled microorganisms have adapted to locomotion using cilia, flagella, or pseudopods.
Due to their small size and structural characteristics, protozoa can live in even the most protected tissues of the body.Parasites from the protozoan kingdom are agents that cause diseases of varying severity, some of which can even lead to death.
Getting rid of unicellular organisms is complicated by the fact that they are able to become covered 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 way of life.
Table “Classes and representatives of protozoan parasites”
| Class | Brief description | Representatives |
| Flagellates | The cells have an oval shape, have a flagellum for movement, advance in a string, and can thus penetrate deeply into the liquid medium.Flagellate colonies can reach 10 thousand individuals.Most species live in tropical and subtropical climates. | Leishmania, Giardia, Trichomonas, Trypanosoma. |
| Sardcodae (rhizopods) | The movements are carried out with the help of pseudopods and have a variable body shape. | Dysenteric amoeba |
| Sporozoa | They got their name due to the presence of a spore stage in their development.Located in tissues and cells, they can cause hepatitis or anemia. | Piroplasmas, Babesia, Coccidia, Plasmodium falciparum. |
| Ciliates | Move with the help of cilia, can live trapped or swim freely | Balantidium |
Depending on the location, unicellular parasites are divided into 2 types:
- endogenous (lives in internal organs and systems);
- exogenous (choose the skin as a place of residence).
Human protozoan parasites can move throughout the body and infect various organs and tissues.
What diseases are caused by flagellates and ciliates?
Class Flagellates
- Leishmania causes cutaneous leishmaniasis (Pendinsky's ulcer) and visceral leishmaniasis, the first manifests itself as constantly rotting ulcers on the body and the second 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 mucous 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 hot climates.
- Trichomonas (depending on the 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 (enlarge), cerebrospinal fluid, blood and spleen, as a result of which the functioning of the spleen and liver is disturbed, the patient suffers from drowsiness and may die.
Ciliate class
Balantidia is the causative agent of balantidiasis, affecting the mucous membrane of the large intestine.A clear sign of this parasite is diarrhea with mucus and blood.This disease usually ends in death.
What diseases are caused by rhizomes and sporozoa?
Class of sporozoans
- The malaria plasmodium enters the blood and liver and causes malaria.Symptoms of the disease are fever, chills or fever, central nervous system disorders, and death is possible.It is transmitted through bites from malaria mosquitoes and is transmitted by humans.
- The causative agent of toxoplasmosis is toxoplasma, which affects the central nervous system, digestive organs, muscle tissue and eyes.At first it occurs without symptoms, then disturbances in the functioning of certain organs are observed.
Class sardcode
Dysenteric amoeba is the causative agent of amoebiasis, affecting the mucous membrane of the large intestine and, less commonly, the bladder and skin.It may be asymptomatic or manifest with vomiting, diarrhea mixed with blood and low fever (up to 37.5 degrees).Symptoms appear 7 to 10 days after the amoebas enter the body.
Less common are extraintestinal forms of the disease, which affect the liver, lungs or other organs.This disease is common in Asian and tropical countries.
Infection routes
Single-celled parasites enter our body in different ways - through the skin or through natural openings in the human body.
There are four main forms (routes) of human infection with a parasitic disease:
- the contact-household route opens in case of unsanitary conditions and non-compliance with the rules of personal hygiene (during handshakes or using household items, bathing in dirty water, cysts enter the human body and begin to develop), trypanosomes and trichomonas are transmitted via this route;
- through products contaminated with parasites (meat, especially 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, the body of a new carrier (this route of infection is especially common among children: contact with animals, eating dirty fruit, playing in a dirty sandbox);
- transmissible (malaria) – transmission of protozoan parasites through bites together 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, as the parasites penetrate the placenta;
- together with contaminated blood (blood transfusion and other medical procedures, injections, including narcotic drugs, during intimacy) - contact with blood;
- during sexual intercourse - sexual intercourse.
Infection prevention
To prevent infection with single-celled organisms, a person must follow a number of simple rules:
- adequate heat treatment of fish and meat, milk control;
- You can eat only those products that have passed sanitary inspection;
- washing fruits before eating and simply soaking them in water is not enough;you need to wash them well and, if possible, pour boiling water over them;
- avoid casual sexual contacts;
- prevention of insect bites (use of special creams, mosquito nets);
- regular medical examinations for suspected infection and for prevention;
- increase immunity, including through the consumption of garlic, oranges, carrots, green tea, dried fruits, rice porridge;
- basic knowledge of which protozoa parasitize the human body and how they get there.
It's easy to follow these rules, the main thing is regularity.
Information about groups of parasites, examples of where single-celled parasites live, helps to choose priority among the preventive measures mentioned.
With proper prevention, and in case of illness - surgical treatment, parasites will not harm your body.