Trypanosome: Life Cycle, Structure And Habitat

Table of contents:

Trypanosome: Life Cycle, Structure And Habitat
Trypanosome: Life Cycle, Structure And Habitat

Video: Trypanosome: Life Cycle, Structure And Habitat

Video: Trypanosome: Life Cycle, Structure And Habitat
Video: Sleeping sickness by trypanosoma 2023, May

Trypanosome is a unicellular parasite that provokes the development of trypanosomiasis. This disease manifests itself in acute and chronic forms. Trypanosomes are pathogenic microorganisms that are very dangerous to human health.


  • 1 Characteristics of trypanosome
  • 2 Life cycle
  • 3 Development of the disease
  • 4 Trypanosomiasis

    • 4.1 American trypanosomiasis
    • 4.2 African trypanosomiasis
  • 5 Diagnosis of the disease
  • 6 Risk factors

Characteristics of trypanosome

Trypanosomes can only exist in the host's body. These are heterotrophic parasites from the trypanosome family.

Trypanosomes are very dangerous for the human body or animal. They cause serious illnesses that can be fatal in some cases.

The structure of trypanosomes is represented by a longitudinal shape in the form of an elongated oval, pointed at the ends. The size of the parasite is from 12 to 70 microns. The parasite is a unicellular organism that includes a nucleus and cytoplasm. The body structure of trypanosomes changes depending on the development cycle:

  1. The habitat of the trypomastigote is in the body of the final host and is the invasive stage;
  2. Epimastigote is contained in the body of the carrier;
  3. Amastigote lives in the body of a permanent owner, is incapable of movement. Subsequently, they turn into trypomastigotes.

Reproduction of this species of parasites occurs asexually. With the help of longitudinal division

Life cycle

The life cycle of trypanosomes takes place in the body of two hosts; in the external environment, the parasite is not active.


The habitat is the insect's alimentary canal, where the parasite develops within 20 days. As the trypanosome develops, it moves towards the insect's salivary glands. When an infected insect bites a person, the parasite, along with the bite, enters the person's body.

In the developmental cycle of trypanosomes, humans are the ultimate host. For ten days after the bite, the trypanosome stays under the human skin, then it enters the bloodstream and affects the internal organs.

The organ of movement is the flagellum, which stretches along the body of the parasite with an undulating membrane.

To feed these parasites, they need glycoproteins and carbohydrates, which they obtain from the blood. Nutrition is carried out with the help of the entire shell of the parasite's body, since these simplest organisms do not have any adaptations for fixing to the walls of blood vessels.

Disease development

An infected insect, as mentioned above, infects a person during a bite. Initially, the parasites reside in skin cells for ten years.


At the next stage, trypanosomes are fixed in the place where their further development will take place. Parasites are fixed in:

  • cerebrospinal fluid;
  • lymph nodes;
  • muscle tissue of the heart;
  • internal organs.

From this point on, the parasites begin to multiply. The active activity of parasites leads to intoxication of the host organism. Parasites destroy the tissues of the organs in which they have settled. This, in turn, leads to serious consequences, and even death.

Trypanosome feeds on blood cells, brain tissue, serous fluid


Trypanosomiasis has two types. This disease is divided into American and African trypanosomiasis. Each type of disease has its own symptoms and signs. The disease is difficult to treat. The specific course of therapy for this disease has not been sufficiently developed at the moment.

The acute form of trypanosomiasis is treated with chemotherapy. The chronic form does not respond to treatment with antiprotozoal drugs. Before starting treatment, you will need to undergo an examination. It is necessary to have an idea of what trypanosomiasis is.

American trypanosomiasis

This protozoal disease is referred to as Chagas disease.

The infection is carried by bed bugs. When bitten, insects infect:

  • dogs;
  • cats;
  • rats;
  • pigs;
  • possums;
  • anteaters;
  • monkeys;
  • human.

The disease begins with an acute phase, which is accompanied by the following symptoms:

  • fever;
  • temperature rise up to 40 degrees;
  • swelling;
  • headaches;
  • swollen lymph nodes;
  • enlargement of the spleen and liver.

The disease quickly turns into a chronic stage. From that moment on, she begins to progress without clearly expressed signs. However, the internal organs continue to gradually deteriorate

American trypanosomiasis is common in South and Central America and Mexico.

African trypanosomiasis

The carrier of the African variant of the disease is the tsetse flies. The disease is identified by the following symptoms:

  • fever;
  • rashes on the skin;
  • enlarged lymph nodes;
  • local edema;
  • confused consciousness;
  • lack of coordination;
  • severe headaches;
  • damage to the central nervous system.

African trypanosomiasis, in turn, is subdivided into two more forms:

  • Gambian trypanosomiasis;
  • Rhodesian trypanosomiasis.

The Gambian variant is the most common. This infection affects 97% of the total number of people infected. The disease may not show any symptoms for a very long time. And to manifest itself when the central nervous system has already been significantly affected.

The second, the Rhodesian variant, is a rather rare occurrence. The disease is diagnosed in only 3% of people. This ailment is characterized by rapid development, it affects the central nervous system of a person.

The disease is widespread in tropical African countries. Every year up to 40 thousand people are infected with it, according to official figures, the real number of cases is much higher.

Diagnosis of the disease

The early phase of the disease proceeds in an acute form, during this period the symptoms are very pronounced. At this stage, the disease is diagnosed according to the clinical picture, in addition, the patient is prescribed:

  • puncture of the lymph node;
  • examination of cerebrospinal fluid;
  • serological examination, the purpose of which is to detect antibodies to trypanosome.

The results of the examination will help the doctor determine the tactics of treatment.

The prognosis for severe disease is poor. The infected person develops heart failure, the risk of death increases

Risk factors

The tsetse fly is found only on the African continent. Most of the rural population is at risk of infection. The disease can expand the geography of infection under the influence of the following factors:

  • social upheaval;
  • population migration;
  • moving cattle;
  • insufficient preventive work of health organizations to carry out preventive measures.

There is currently no vaccine for trypanosoma. To exclude infection with trypanosomiasis, you must observe safety measures:

  • do not wear bright clothes when going outdoors;
  • put on a mosquito net if necessary;
  • use insecticides to control insects.

American trypanosomiasis is common in the American continent. Cases of infection with this disease have been reported in Latin America, USA, Canada. In recent years, the incidence rate in these countries has been reduced due to intensive control over this disease.

Popular by topic