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 of 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 of a certain shape, some can change it, the cell has organelles that maintain viability.Unicellular microorganisms have adapted to locomotion with the help of cilia, flagella or pseudopods.
Thanks 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 out unfavorable conditions for their existence.
Classification of the simplest inhabitants of the human body
Unicellular parasites are divided into 4 classes, depending on the structure and lifestyle of the cell.
table "Classes and representatives of protozoan parasites"
| class | Short description | representatives |
| Flagellates | The cells are oval-shaped, have a flagellum that promotes movement, and move forward with a cord, so they are able to penetrate deeply into the liquid medium.Flag colonies can reach 10,000 individuals.Most species live in tropical and subtropical climates. | Leishmania, Giardia, Trichomonas, Trypanosoma. |
| Sardcodea (rhizopods) | Movements are performed with the help of pseudopods and they have a variable body shape. | Dysenteric amoeba |
| Sporozoa | They got their name because of the presence of the spore stage in their development.Localized in tissues and cells, they can cause hepatitis or anemia. | Piroplasmas, Babesia, Coccidia, Plasmodium falciparum. |
| Cilia | It moves with the help of cilia, it can live attached or swim freely | Balantidium |
Depending on the place of localization, unicellular parasites are divided into two types:
- endogenous (lives in internal organs and systems);
- exogenous (their place of residence must be the skin).
Human protozoan parasites can move throughout the body and infect different organs and tissues.
What diseases are caused by ciliates and animals with ciliates?
Class ensigns
- Leishmania is caused by cutaneous leishmaniasis (Pendinsky's ulcer) and visceral leishmaniasis, the first manifests itself in the form of constantly rotting ulcers on the body, and the second causes 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 mucous membrane of the intestines or gall bladder.After the defeat, people begin to suffer from asthma, mental disorders (most often depression), and the skin dries out.Giardia is common in countries with hot climates.
- Trichomonas (depending on habitat - oral, intestinal and genital or urogenital) causes trichomoniasis.After infection, a person feels itching in the area of the reproductive system and notices abnormal discharge from the genitals.The greatest danger of this disease is the high risk of infertility.
- Trypanosoma causes African or American trypanosomiasis (the first is sleeping sickness, the second is Chags disease).It affects the lymph nodes (they enlarge), the cerebrospinal fluid, the blood and the spleen, as a result of which the functioning of the spleen and liver is disturbed, the patient suffers from drowsiness and may die.
Brilliant class
Balantidia is the causative agent of balantidiasis, which affects the mucous membrane of the large intestine.A clear sign of the parasite is diarrhea with mucus and blood.This disease often ends in death.
What diseases do rhizomes and sporozoa cause?
Class Sporozoa
- Plasmodium malaria enters the blood and liver and causes malaria.Symptoms of the disease include fever, chills or fever, central nervous system disorders, and death is possible.Malaria is spread through mosquito bites and is also 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 appears asymptomatic, and then disturbances in the functioning of certain organs can be observed.
Class sardcode
Dysenteric amoeba is the causative agent of amoebiasis, which affects the mucous membrane of the large intestine, less often the bladder and the skin.It can be asymptomatic, or it can be manifested by vomiting, diarrhea mixed with blood, and a low fever (up to 37.5 degrees).Symptoms appear 7-10 days after the amoebae enter the body.
Extraintestinal forms of the disease affecting the liver, lungs or other organs are less common.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 the natural openings of the human body.
There are four main ways (routes) of human infection with a parasitic disease:
- the contact-household path opens in case of non-hygienic conditions and non-observance of personal hygiene rules (cysts enter the human body and begin to develop when shaking hands or using household items, bathing in dirty water), trypanosomes and trichomonas are spread along this path;
- they can be disinfected by heat treatment through products contaminated with parasites (meat, especially wild animals, fish, dairy products);an example of a disease that spreads in this way is toxoplasmosis;
- faecal-oral route: the parasites leave the body with faeces or vomit, then get into water, food, household items, the hands of the owner, and through them into the organism of a new carrier (this route of infection is especially common in children: contact with animals, eating unwashed fruit, playing in a dirty sandbox);
- infectious (malaria) - transmission of protozoan parasites through a bite 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 route is called transplacental, since the parasites penetrate the placenta;
- together with contaminated blood (blood transfusion and other medical procedures, injections, including drugs, during intimacy) - contact with blood;
- during sexual intercourse - genital tract.
Prevention of infection
To prevent infection with single-celled organisms, a person must follow a number of simple rules:
- appropriate heat treatment of fish and meat, milk regulation;
- You can only consume products that have passed the health inspection;
- it is not enough to wash the fruits before eating and simply immerse them in water;they must be thoroughly washed and, if possible, pour boiling water;
- avoiding casual sex;
- prevention of insect bites (use of special creams, mosquito nets);
- regular medical examination for suspicion of infection and prevention;
- increasing immunity, including the consumption of garlic, oranges, carrots, green tea, dried fruits, rice porridge;
- basic knowledge about which protozoans are parasitic in 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 the life of single-celled parasites help to choose the priority among the named preventive measures.
With adequate prevention, in case of illness - with surgical treatment, parasites do not harm the body.