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 protozoa kingdom 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 single cell of a certain shape, some can change it, the cell has organelles that maintain vitality.Unicellular microorganisms have adapted to move by means of cilia, flagella or pseudopods.
Due to their small size and structural characteristics, protozoa can live even in the most protected tissues of the body.Parasites of the protozoan kingdom cause diseases of varying severity, some of which can even lead to death.
Getting rid of unicellular organisms is made difficult by the fact that they can cover themselves with a protective shell (cyst) and wait for conditions unfavorable for their existence.
Classification of the simplest inhabitants of the human body
Unicellular parasites are divided into 4 classes, depending on the cell structure and way of life.
Table "Classes and representatives of protozoan parasites"
| Class | Short description | Representatives |
| Flagellate | The cells are oval in shape, have a flagellum for movement, move forward with a cord, so they can penetrate deeply into the liquid medium.Colonies of flagellates can reach 10 thousand individuals.Most species live in tropical and subtropical climates. | Leishmania, Giardia, Trichomonas, Trypanosoma. |
| Sardcodae (Rhizopods) | Movements are performed with the help of pseudopods and have a variable body shape. | Dysenteric amoeba |
| Sporozoans | They got their name because of the presence of a spore phase in their development.Localized in tissues and cells, they can cause hepatitis or anemia. | Piroplasmas, Babesia, Coccidia, Plasmodium falciparum. |
| Ciliates | It moves with the help of cilia, it can live attached or swim freely | Balantidium |
Depending on the localization location, unicellular parasites are divided into 2 types:
- endogenous (live in internal organs and systems);
- exogenous (select the skin as the 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 former manifesting as constant festering ulcers on the body, and the latter causing inflammation and bleeding.Leishmania enters the body through warm-blooded animals or mosquito bites and affects the skin, heart, kidneys, blood and bone marrow.
- Giardia, the causative agent of giardiasis, affects the lining of the intestines or gall bladder.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 the habitat - oral, intestinal and genital or urogenital), causes trichomoniasis.After infection, a person feels itching in the area of the reproductive system, and a 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), cerebrospinal fluid, blood and spleen, due to 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, which affects the mucous membrane of the large intestine.A clear sign of this parasite is diarrhea with mucus and blood.This disease often ends in death.
What diseases are caused by rhizomes and sporozoa?
Sporozoan class
- Plasmodium malaria enters the blood and liver and causes malaria.Symptoms of the disease are fever, chills or fever, disorders of the central nervous system, and death is possible.It is transmitted by the bite of malaria mosquitoes, and it 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 appears without symptoms, then disorders in the work of certain organs are observed.
Sardcode classes
Dysenteric amoeba is the causative agent of amebiasis, which affects the mucous membrane of the large intestine, and less often the bladder and skin.It can be asymptomatic, or it can be signaled by vomiting, diarrhea mixed with blood and a low temperature (up to 37.5 degrees).Symptoms appear 7-10 days after the amoebas enter the body.
Extraintestinal forms of the disease affecting the liver, lungs or other organs are rarer.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 natural openings in the human body.
There are four main ways (routes) of human infection with a parasitic disease:
- contact-household is opened in case of unhygienic conditions and non-observance of personal hygiene rules (during handling or use of household items, bathing in dirty water, cysts enter the human body and begin to develop), trypanosomes and trichomonas are transmitted through this method;
- through products contaminated with parasites (meat, especially wild animals, fish, dairy products), 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, hands of the owner and through them into the body of the new carrier (this route of infection is especially common in children: contact with animals, eating unwashed 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 route is called transplacental, because the parasites penetrate through the placenta;
- together with contaminated blood (blood transfusion and other medical procedures, injections, including narcotic ones, during intimacy) - contact with blood;
- during intercourse - genital tract.
Prevention of infection
To prevent infection with single-celled organisms, a person must follow a series of simple rules:
- proper thermal processing of fish and meat, control of milk;
- You can eat only those products that have passed a sanitary inspection;
- washing the fruit before eating and simply soaking it in water is not enough;it is necessary to wash them well and, if possible, pour boiling water over them;
- avoiding casual sexual contacts;
- prevention of insect bites (use of special creams, mosquito nets);
- regular medical examinations due to suspicion of infection and for prevention;
- increasing immunity, including the consumption of garlic, oranges, carrots, green tea, dried fruits, rice porridge;
- basic knowledge about which protozoa parasitize the human body and how they get there.
It is easy to follow these rules, the main thing is regularity.
Data on parasite groups, examples of which unicellular parasites live, help to prioritize among the listed preventive measures.
With proper prevention, and in case of illness - surgical treatment, parasites will not harm your body.