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, which is accepted in medicine and biology, is unicellular organisms.
These creatures consist of one cell of a certain shape, some of them can change it, the cell has organelles that maintain viability.Unicellular microorganisms have adapted to locomotion using cilia, flagella or pseudopods.
Due to their small size and structural features, protozoa can survive even in the most protected tissues of the body.Parasites of the protozoan kingdom are causative agents of diseases of varying severity, some of which can even lead to death.
It is complicated to get rid of single-celled organisms because they are able to be covered with a protective shell (cyst) and stay out under unfavorable conditions for their life.
Classification of the simplest inhabitants of the human body
Unicellular parasites are divided into 4 classes, depending on the structure of the cell and the way of life.
Table "Classes and representatives of protozoan parasites"
| Class | Brief description | Representatives |
| Flagellates | The cells have an oval shape, they have flagella for movement, they move forward with a cord, so they can go 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 made with the help of pseudopods and they have a variable body shape. | Amoeba dysenteric |
| Sporazoans | They got their name because of the presence of spores at a stage in their development.Localized in tissues and cells, they can cause hepatitis or anemia. | Piroplasmas, Babesia, Coccidia, Plasmodium falciparum. |
| Ciliates | Move with the help of cilia, can live attached or swim freely | Balantidium |
Depending on the site of localization, unicellular parasites are divided into 2 types:
- endogenous (live in the internal organs and systems);
- exogenous (choose the skin as their residence).
Human protozoan parasites can move throughout the body and infect various organs and tissues.
What diseases are caused by flagella and ciliates?
Class Flagellates
- Leishmania causes cutaneous leishmaniasis (Pendinsky 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 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 is observed from the genitals.The biggest risk associated with this disease is the high risk of developing infertility.
- African or American trypanosoma causes trypanosomiasis (the first is sleeping sickness, the second 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 affected, the patient suffers from drowsiness and may die.
Class Ciliate
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 do rhizomes and sporozoans cause?
Class sporozoon
- The malarial plasmodium 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 bites of malarial 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.
Sardcode class
Dysenteric amoeba is the causative agent of amoebiasis, which affects the mucous membrane of the large intestine, and less commonly, the bladder and the skin.It may be asymptomatic, or it may manifest 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 the 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 ways (pathways) of human infection with a parasitic disease:
- the household contact route opens in case of unsanitary conditions and non-compliance with 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), trypanosomes and trichomonas are transferred 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 way: parasites leave the body with feces or vomit, then get into water, food, household items, hands of the owner, and through them into the body of a new carrier (this way 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 along 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, as parasites enter through the placenta;
- together with contaminated blood (blood transfusion and other medical procedures, injections, including narcotic ones, during intimacy) - blood contact;
- during intercourse — sexual contract.
Prevention of infection
To prevent infection with unicellular organisms, a person must follow a few simple rules:
- proper heat treatment of fish and meat, milk control;
- You can only eat those products that have passed a sanitary inspection;
- it is not enough to wash fruit before eating, and immerse them in water;you must 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 by eating garlic, oranges, carrots, green tea, dried fruits, rice porridges;
- 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 of which live single-celled parasites, helps to choose priority among designated preventive measures.
With proper prevention, and in case of illness - surgical treatment, parasites will not harm your body.