Despite their microscopic size, human protozoan parasites are one of the most dangerous microorganisms that can cause serious diseases.
General information about representatives of protozoa
The kingdom 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 with a specific shape, some can change it, the cell has organelles that maintain viability.Unicellular microorganisms have adapted to locomotion by means of cilia, flagella or pseudopods.
Due to their small size and structural features, protozoa can live even in the most protected tissues of the body.Parasites in the protozoan kingdom are the causative agents of 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 be covered by a protective shell (cyst) and await conditions unfavorable to their existence.
Classification of the simplest inhabitants of the human body
Unicellular parasites are divided into 4 classes, depending on the cell's structure and way of life.
Table "Classes and representatives of protozoan parasites"
| class | Short description | Representatives |
| Flagellates | The cells are oval in shape, have a flagellum for movement, move forward with a string and thus can penetrate deep 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) | Movements are performed using 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.Localized in tissues and cells, they can cause hepatitis or anemia. | Piroplasmas, Babesia, Coccidia, Plasmodium falciparum. |
| Ciliates | Move using cilia, can live attached or swim freely | Balantidium |
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 their 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 flagella
- Leishmania causes cutaneous leishmaniasis (Pendinsky ulcer) and visceral leishmaniasis, the first appearing as constant rotting sores on the body, and the second causing 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 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 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 main 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 Chag's disease).It affects the lymph nodes (they enlarge), cerebrospinal fluid, blood and spleen, as a result of which the function of the spleen and liver is disturbed, the patient suffers from drowsiness and may die.
Ciliate class
Balantidia is the cause of balantidiasis, which affects the lining 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
- The malaria plasmodium enters the blood and liver and causes malaria.Symptoms of the disease are fever, chills or fever, disturbances in the central nervous system, and death is possible.It is transmitted through the bite of malaria mosquitoes and 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, which affects the lining of the colon and less commonly the bladder and skin.It can be asymptomatic or it can signal itself with vomiting, diarrhea mixed with blood and low-grade fever (up to 37.5 degrees).Symptoms appear 7-10 days after 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.
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 pathways (pathways) of human infection with a parasitic disease:
- the contact-household route opens in case of unhygienic 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 through this route;
- through products contaminated with parasites (meat, especially wild animals, fish, dairy products), they can be disinfected using 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 penetrate 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);
- communicable (malaria) - transmission of protozoan parasites through bites along with saliva from the carrier.
Much less often, parasites enter the body in the following ways:
- from mother to fetus during pregnancy, this route is called transplacental, as parasites enter through the placenta;
- together with contaminated blood (blood transfusion and other medical procedures, injections, including narcotic, during intimacy) - blood contact;
- during intercourse - sexual channel.
Prevention of infection
To prevent infection with single-celled organisms, a person must follow a number of simple rules:
- correct heat treatment of fish and meat, milk control;
- You can only eat the products that have passed sanitary inspection;
- washing fruits before eating and simply dipping them in water is not enough;you must wash them thoroughly and, if possible, pour boiling water over them;
- avoidance of casual sexual contacts;
- prevention of insect bites (use of special creams, mosquito nets);
- regular medical examinations for suspected infection and for prevention;
- increased immunity, including through consumption of garlic, oranges, carrots, green tea, dried fruit, rice porridge;
- basic knowledge of which protozoa parasitize the human body and how they get there.
It is easy to follow these rules, the main thing is regularity.
Information about groups of parasites, examples where unicellular parasites live, helps to choose priority among the mentioned preventive measures.
With proper prevention, and in case of disease - surgical treatment, parasites will not harm your body.