Human protozoan parasites, despite their microscopic size, are one of the most dangerous microorganisms that can cause serious diseases.
General information on representatives of protozoa
The protozoan 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 organism.
These creatures consist of a cell of a certain shape, some can change it, the cell has organelles that maintain vitality.Unicellular microorganisms have adapted to locomotion using cilia, flagella, or pseudopodia.
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 are causative agents of diseases of varying severity, some of them can even lead to death.
Getting rid of unicellular organisms is complicated by the fact that they are able to cover themselves with a protective shell (cyst) and wait for unfavorable conditions for their existence.
Classification of the simplest inhabitants of the human body
Single-celled parasites are divided into 4 classes, depending on the structure of the cell and lifestyle.
Table “Classes and representatives of protozoan parasites”
| Class | Brief description | Representatives |
| Scourged | The cells are oval in shape, have a flagellum for movement, advance with a cord, thus being able to penetrate deeply into the liquid environment.The flagellated colonies can reach 10 thousand individuals.Most species live in tropical and subtropical climates. | Leishmania, Giardia, Trichomonas, Trypanosoma. |
| Sardcodae (rhizopods) | The movements are performed with the help of pseudopods and have a variable body shape. | Dysenteric amoeba |
| Sporozoa | They got their name from the presence of a spore stage 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, can live attached or swim freely | Balantidio |
Depending on the location of localization, unicellular parasites are divided into 2 types:
- endogenous (lives in internal organs and systems);
- exogenous (choose 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
- Leishmaniasis causes cutaneous leishmaniasis (Pendinsky ulcer) and visceral leishmaniasis, the former manifests 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 mucous membranes of the intestine 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 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 former is sleeping sickness, the latter is Chags disease).It affects the lymph nodes (they enlarge), cerebrospinal fluid, blood and spleen, as a result of which the functioning of the spleen and liver is disrupted, the patient suffers from drowsiness and may die.
Ciliated class
Balantidia is the causative agent of balantidiasis, which affects the mucosa 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 sporozoans?
Sporozoic class
- Malarial 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 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 tissue and eyes.At first it manifests itself without symptoms, then disturbances in the functioning of some organs are observed.
Class sardcode
Dysenteric amoeba is the causative agent of amoebiasis, which affects the mucosa of the large intestine and, less commonly, the bladder and skin.It can be asymptomatic or present with vomiting, diarrhea mixed with blood and mild fever (up to 37.5 degrees).Symptoms appear 7-10 days after the amoebae 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.
Routes of infection
Single-celled parasites enter our body in several ways: through the skin or natural openings in the human body.
There are four main ways (paths) of human infection with a parasitic disease:
- the contact-household route opens in case of unsanitary conditions and failure to comply with the rules of personal hygiene (during shaking hands or using household items, bathing in dirty water, cysts enter the human body and begin to develop), through this route trypanosomes and trichomonas are transmitted;
- through products contaminated by parasites (meat, especially of 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, the owner's hands and through them into the body of a new carrier (this route of infection is especially common among 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 the mother to the fetus during pregnancy, this path is called transplacental, since the parasites penetrate through the placenta;
- together with contaminated blood (blood transfusions and other medical procedures, injections, including narcotic ones, during intimacy) - contact with blood;
- during sexual intercourse - sexual trait.
Prevention of infection
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 health inspection;
- washing fruit before eating and simply soaking it in water is not enough;you need to wash them carefully and, if possible, pour boiling water over them;
- avoid casual sexual contact;
- prevention of insect bites (use of special creams, mosquito nets);
- regular medical visits for suspected infection and for prevention;
- increase immunity, including through the consumption of garlic, oranges, carrots, green tea, dried fruits, rice porridge;
- basic knowledge about which protozoans 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 where unicellular parasites live, helps to choose the priority among the mentioned preventive measures.
With proper prevention, and in case of disease, surgical treatment, parasites will not harm your body.