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 of this kingdom, adopted in medicine and biology, is unicellular organisms.
These creatures consist of a single cell of a certain shape, some can change it, the cell has organelles that keep it alive.Unicellular microorganisms are adapted for movement 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 protozoan kingdom are agents of disease of varying severity, some of which can even cause death.
Getting rid of unicellular organisms is made difficult by the fact that they can cover themselves with a protective shell (cyst) and wait for unfavorable conditions for their existence.
Classification of the simplest inhabitants of the human body
According to the cell structure and way of life, unicellular parasites are divided into 4 classes.
Table "Classes and representatives of protozoan parasites"
| class | Brief description | representatives |
| Flagellates | The cells are oval in shape, have a flagellum for movement, move forward with a cord, so they can penetrate deep into the liquid environment.Flagellate colonies can reach 10 thousand individuals.Most species live in tropical and subtropical climates. | Leishmania, Giardia, Trichomonas, Trypanosoma. |
| Sardcodae (rhizopods) | Movements are carried out with the help of pseudopods and have a changing body shape. | Dysenteric amoeba |
| Sporozoans | They got their name because of 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 | Moves with the help of cilia, can live attached or swim freely | Ballantidium |
According to the location of localization, single-celled 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 do flagellates and cilia cause?
Class Flagellates
- Leishmania causes cutaneous leishmaniasis (Pendinsky's ulcer) and visceral leishmaniasis, the former manifesting as persistent festering sores on the body, 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, infects the mucous tissues of the intestines or gallbladder.After defeat, people suffer from asthma, mental disorders (most often depression) and 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.
- Trypanosomes cause African or American trypanosomiasis (the first is sleeping sickness, the second is Chagi's disease).It affects the lymph nodes (enlargement), cerebrospinal fluid, blood and spleen, as a result of which the functioning of the spleen and liver is disturbed, the patient suffers from drowsiness and may die.
ciliated class
Balantidia is the causative agent of balantidiosis, 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 sporozoa cause?
Sporozoan class
- Plasmodium malaria enters the blood and liver and causes malaria.Symptoms of the disease include fever, chills or fever, central nervous system disorders and possible death.It is transmitted by the bite of malarial mosquitoes and transmitted to humans.
- The causative agent of toxoplasmosis is Toxoplasma, which affects the central nervous system, digestive organs, muscle tissue and eyes.At first, it appears without symptoms, then there is a violation of the functioning of certain organs.
Class password
Dysenteric amoeba is the causative agent of amebiasis, which affects the mucous membrane of the large intestine and less often the bladder and skin.It can be asymptomatic, or it can indicate vomiting, bloody diarrhea and low-grade fever (up to 37.5 degrees).Symptoms appear 7-10 days after amoeba enters the body.
Less common are extraintestinal forms of the disease that affect the liver, lungs, or other organs.This disease is common in Asian and tropical countries.
Ways of infection
Single-celled parasites enter our body in different ways - through the skin or through natural openings in the human body.
There are four main ways (routes) of human infection with a parasitic disease:
- The contact-household route is opened in case of unsanitary conditions and insecurity of personal hygiene rules (when shaking hands or using household items, bathing in dirty water, cysts enter the human body and begin to develop), in this way trypanosomes and trichomonas are transferred;
- Products contaminated with parasites (meat, especially 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, hands of the owner and through them into the body of a new carrier (this route of infection is especially common in children: contact with animals, eating unwashed fruits, playing in dirty sand);
- Contagious (malaria) – transmission of protozoan parasites through a bite along with the carrier's saliva.
Very rarely, parasites enter the body in the following ways:
- During pregnancy, this path from mother to fetus is called transplacental, because the parasites enter the placenta;
- with contaminated blood (blood transfusions and other medical procedures, injections, including during narcotic intercourse) - contact with blood;
- during intercourse - genital tract.
Prevention of infection
To avoid infection with cellular organisms, a person should follow a few simple rules:
- proper heat treatment of fish and meat, control of milk;
- You can eat only those products that have passed sanitary inspection;
- Washing the fruit before eating and simply putting it in water is not enough;You should wash them well and, if possible, pour boiling water;
- avoiding casual sexual contacts;
- Prevention of insect bites (use of special creams, mosquito nets);
- regular medical examinations for suspected infection and prevention;
- increasing immunity, including by consuming garlic, orange, carrot, green tea, dried fruit, rice porridge;
- Basic knowledge of which protozoa parasitize the human body and how they get there.
Following these rules is easy, the main thing is regularity.
Information about groups of parasites, examples of where single-celled parasites live, helps us to choose the priority among the named preventive measures.
With proper prevention, and in case of illness - with surgical treatment, parasites will not harm your body.