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.
The second name of this world accepted in medicine and biology is unicellular organism.
These creatures have a cell of a certain shape, some can change it, the cell contains organelles that maintain viability.Single-celled microorganisms have adapted to locomotion using cilia, flagella, or pseudopods.
Due to their small size and structural features, protozoa can live in even the most protected tissues of the body.Parasites of the Protozoa kingdom are causative agents of diseases of varying severity, some of them can even lead to death.
Getting rid of single-celled organisms is complicated by the fact that they are able to become covered with a protective cover (cyst) and wait for unfavorable conditions for their survival.
Classification of the simplest inhabitants of the human body
Single-celled parasites are divided into 4 classes on the basis of cell structure and lifestyle.
Table "Classes and representatives of protozoan parasites"
| Class | Brief summary | Representative |
| flag bearer | The cells are oval in shape, they have a flagellum for movement, they move along a cord, thus being able to penetrate deeply into the liquid medium.Flagellate colonies can reach up to 10 thousand individuals.Most species live in tropical and subtropical climates. | Leishmania, Giardia, Trichomonas, Trypanosoma. |
| Sardacode (Rhizopods) | Movements are carried out with the help of pseudopods and their body shape is variable. | dysentery amoeba |
| sporozoans | They got this name due to the presence of a spore stage in their development.Localized in tissues and cells, they can cause hepatitis or anemia. | Piroplasma, Babesia, Coccidia, Plasmodium falciparum. |
| ciliates | Move with the help of cilia, can remain attached or swim independently | balantidium |
Depending on the place of localization, single-celled parasites are divided into 2 types:
- Endogenous (residing in internal organs and systems);
- Exogenous (choose the skin as their habitat).
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 ulcer) and visceral leishmaniasis, the former appearing as persistent festering ulcers on the body, and the latter causing inflammation and bleeding.Leishmania enters the body through the bite of warm-blooded animals or mosquitoes and affects the skin, heart, kidneys, blood and bone marrow.
- Giardia, the causative agent of giardiasis, affects the mucous tissues of the intestines or gall bladder.After defeat, people begin to suffer from asthma, mental disorders (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 biggest 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 Chagas' disease).It affects the lymph nodes (they become larger), 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.
ciliate class
Balantidia is the causative agent of Balantidiasis, which affects the mucous membrane of the large intestine.The obvious sign of this parasite is diarrhea with mucus and blood.This disease often ends in death.
What diseases are caused by rhizozoans and sporozoans?
sporozoan class
- 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 spread by the bite of malarial mosquitoes and spread 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 any symptoms, then disturbances in the functioning of some organs are observed.
class shardcode
Dysenteric amoeba is the causative agent of amoebiasis, which affects the mucous membrane of the large intestine, and usually the bladder and skin.It may be asymptomatic, or it may be characterized by vomiting, bloody diarrhea and low-grade fever (up to 37.5 degrees).Symptoms appear 7-10 days after the amoeba enters 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 through natural pores in the human body.
There are four main routes of human infection by parasitic diseases:
- In case of unsanitary conditions and non-observance of the rules of personal hygiene (when shaking hands or using household items, bathing in dirty water, cysts enter the human body and begin to develop), the contact-household path opens, trypanosomes and Trichomonas are transmitted through this path;
- Through products contaminated with parasites (meat, especially of 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 enter water, food, household items, hands of the owner and through them enter 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);
- Infectious (malaria) – transmission of protozoan parasites through bites with the saliva of the carrier.
Much less often, parasites enter the body in the following ways:
- This route, from mother to fetus during pregnancy, is called transplacental, because the parasites enter through the placenta;
- With contaminated blood (including blood transfusions and other medical procedures, injections, intoxicants, during intimacy) - blood contact;
- During sexual intercourse - sexual path.
infection prevention
To prevent infection with unicellular organisms, one must follow several simple rules:
- Proper heat treatment of fish and meat, milk control;
- You can eat only products that have passed sanitary inspection;
- It is not enough to wash fruits and simply soak them in water before eating;You need 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 checkups for suspected infections and prevention;
- increasing immunity, which includes 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.
These rules are easy to follow, the main thing is regularity.
Information about groups of parasites, examples of where single-celled parasites live, helps to choose priority among the named preventive measures.
With proper prevention, and in case of disease - surgical treatment, parasites will not harm your body.