Protozoa parasites

Among the simplest organisms, there are many parasites of animals and humans. Listed below are the parasitic protozoa that cause the most serious and common diseases.

Dysentery amoeba

The dysentery amoeba is similar to the common one, but is smaller and has shorter and wider rhizomes. It enters the human digestive system through the mouth in the cyst stage. In the large intestine, the amoeba leaves the cyst and feeds on bacteria without harming humans. In the future, this simplest organism begins to invade the intestinal wall, feed on red blood cells, and becomes a parasite. Ulcers form in the intestines, depleting the human body. There is a disease amoebic dysentery, or amebiasis.

Dysentery amoeba can enter the bloodstream and reach the liver. Here, too, the parasite leads to the formation of purulent ulcers.

Forming cysts, amoebas leave the human body with undigested food debris. Light cysts are easily spread. If you do not wash your hands and food, then they can become infected.

Malaria plasmodium

Plasmodia are parasitic protozoa. Some types of plasmodia cause malaria in humans. The carrier of the malaria plasmodia is the malaria mosquito. During an insect bite, the plasmodium enters the host's bloodstream. Together with the blood, it reaches the liver, feeds there, grows and multiplies. After that, many plasmodia again enter the bloodstream and begin to parasitize on erythrocytes, destroying them and releasing their waste products, which poison the host. A person develops a fever, he suffers from anemia.

If a malaria patient is bitten again by an anopheles mosquito, now the plasmodia will get from the person to the mosquito. In the body of a mosquito, Plasmodium reproduces sexually.

Malaria is common in Africa. This is a very dangerous disease. Fight against malaria, including the destruction of malaria mosquitoes.


The genus trypanosomes are parasitic protozoa with flagella (related to euglena). Their main host is a vertebrate animal, and insects are usually carriers. Different representatives of trypanosomes cause different diseases of animals and humans. They parasitize mainly in the blood and cerebrospinal fluid. The most famous and common disease caused by the trypanosome species is sleeping sickness.

The carrier of sleeping sickness is the tsetse fly. This disease is typical for tropical Africa. Sleeping sickness develops in two stages: the first weeks of a person are tormented by fever and pain, after a month or more drowsiness occurs, sleep and coordination disturbances, and a change in consciousness. The disease is easier to treat in the first stage.


Giardia is a genus of parasitic flagellate protozoa. Intestinal lamblia causes giardiasis in humans and animals, in which the parasite lives in the small intestine.

lamblia - a genus of flagellated protozoa-parasites

A person becomes infected with giardiasis by eating unwashed food containing Giardia cysts. Coming out of the cyst, lamblia sticks to the intestines and feeds on digested food.


Leishmania is another genus of parasitic protozoa. They cause leishmaniasis in humans and many other animals. The vectors are mosquitoes.

There are different types of leishmaniasis associated with damage to various tissues of the body. One of them is the skin disease Pendinsky ulcer.


Coccidia parasitize many animals, including worms, arthropods, and fish. They cause diseases of coccidiosis, which cause serious damage in livestock and fish farming.

Coccidia settle in the form of spores containing parasite cells.

The genus Toxoplasma belongs to coccidia. Their representatives cause in humans such a widespread disease as toxoplasmosis. A person becomes infected from pets or poorly cooked meat food. Toxoplasma affects many organs, including the nervous system.