Diseases caused by parasites

There are over 200 different species of parasites. Carriers of the eggs of these organisms in most cases are insects, and native mammals.

diseases caused by parasites

The human body at the same time can live up to 5 different parasites. Some he may not even be aware of, but the other huge danger.


Trypanosoma is a parasitic one-celled micro-organism that can live in the human body and cause serious illness. Their parasitism is obligate in nature, so a living organism is the only habitat of the trypanosomes. Diseases caused by these single-celled, combined into 1 group called trypanosomiasis.

The most common and studied types of the following trypanosomes:

  • brucei;
  • cruzi.


Trypanosoma is a single-celled parasite, is spread fly Glossina (tsetse fly) that causes African trypanosomiasis.

Depending on the areas of greatest distribution are the following subtypes:

  • brucei. The causative agent of African trypanosomiasis in animals (rarely humans);
  • equinum. The pathogen has spread widely in North and south Africa (recorded isolated cases of infection in Italy). Lois horses and mules. Cause the so-called disease that is transmitted sexually, symptoms, intense swelling of the genital organs of animals;
  • gambiense. The pathogen has spread to Central and West Africa, causes the chronic form of sleeping sickness to humans;
  • rhodesiense. Live in southern and Eastern Africa and causes acute sleeping sickness to humans (rare animals).

Feature of trypanosomes, other parasites is the presence of these single-cell's ability to evade the human immune defense.

The parasite is an elongated cell consisting of cytoplasm and in the nucleus, in certain stages has a long flagellum, which performs the function of the engine frame. The size of parasites varies from 10 to 70 µm. Reproduction occurs vegetatively (longitudinal distribution).

Structure of trypanosomes varies depending on the body of the host (temporary or final) is located.

There can be 2 stages of the developmental cycle of Trypanosoma brucei:

  1. A special stage. When the intestine of the carrier in the form of parasites, micro-organisms turn into other parasites, localized in the saliva of the insect. A special part of the beginning of active cell division, which produces a large number of parasites. Such a form of existence of trypanosomes in the body of the intermediate host, it has elongated cells with a short flagellum and indirectly pronounced undulating membrane, which runs the body's movement as the flagellum.
  2. Trypanosomatidae. This parasite develops and moves in the body of the final host. The appearance is slightly different than in the previous stage, the body is more elongated, the flagellum is longer, the membrane active.

Trypanosoma cruzi

The vectors are bugs. Causes Chagas disease (American trypanosomiasis). Habitat – South America (sometimes Central).

The life cycle of Trypanosoma cruzi represents the 3 stages of development:

  1. Stage in the life cycle of protozoa of the genus Trypanosoma. In the form of the parasite, the pathogen enters the intestine the fault, if after being bitten by a bug from an infected person;
  2. The next phase of the life cycle of protozoa of the genus Trypanosoma. The intestine of the bug, the parasite develops on another parasite and contact with the skin of a person with feces;
  3. Mastigos. When the epithelium and later the surface layer of the skin or mucous membranes, the pathogen changes its cell-structure, parasite. Mastigos has a circular shape, which is characterized by the absence of flagella and motionless. In this form it is produced, then repeat the cycle of the first to develop the following form of the parasite enters the other tissues, develops a mastigos, etc.
type of parasite

The causes of human infection

A person can be infected with African or American parasite interaction with the insect vector.

The habitat of these insects is concentrated in the tropical and subtropical regions of Africa and South America.

The intermediate hosts of the parasite, in most cases, are a particular bug (in South America, mainly in Argentina) and tsetse fly (in Africa).

Bug the Triatomine is one of the most dangerous insects to man. Its bite is fatal in 9 cases of 10.

Move the body of the final host micro-organism can in 3 ways:

  • directly to the insect bite;
  • blood transfusions;
  • in the womb.

Infection risk are mainly people in poor and densely populated regions of Africa and South America. Lack of personal hygiene, location of housing in a wooded area, dilapidated housing, mud – all triggers the infection.

Tourists need to remember that vaccines against the infection, as the parasite does not exist!

For more information, the risk of infection to a minimum, tourists, exotic countries, South America and Africa should adhere to the following rules:

  • remember to wash fruits under running water before use;
  • wear maximally closed clothes, especially in the dark;
  • skin preparations containing insect repellent;
  • avoid direct contact of bare skin with long grass/bushes;
  • no use of dilapidated buildings;
  • sleep canopy for additional protection from the insects to the bed.

IMPORTANT! Often the cause of infection is a failure to follow the simple measures in self-defense.

Disease pathogenesis

Sleeping sickness

African trypanosomiasis. Depending on the type of pathogen are distinguished:

  • in the acute form;
  • in the chronic form.

Tsetse flies, which carry trypanosomiasis, are not toxic. Its danger lies in the transmission of pathogenic organisms and attack people.

98% of cases of sleeping sickness occurs primarily in the chronic form.

After penetration into the mucosa or the skin layer, starts the incubation period, which lasts up to 3 weeks. Currently, the parasites they share, and then penetrate the lymph nodes (by hitting them) and the blood current, that reaches the tissues of the nervous system. In the chronic form of the disease is considerably slowed down and is hidden, so symptoms may come on slowly and people do not suspect the infection for quite a long time (1 month to several years). Acute course of the disease requires a primary aggressive onset of symptoms, allowing easier diagnosed, but very rare.

Chagas Disease

American trypanosomiasis. The principle of the distribution of trypanosomes in the human body similar to the sleeping sickness, but in this case, the parasite causes degenerative changes, mainly in the heart and the esophagus (rarely liver, adrenal glands) and poisoning the body of toxins – products of its life. The incubation period lasts up to 2 weeks. Next comes the acute phase of the disease, which is manifested mild symptoms. 2-3 months after the infection, the disease becomes chronic. Symptoms are absent or almost invisible. Blood bank Latin America, the percentage of infection of blood parasites is greater than AIDS, and it can be up to 52%.


African trypanosomiasis

The bite of the tsetse fly has been formed inflammatory lesions with a diameter of 10 cm, which is characterized by:

  • itching;
  • redness;
  • hyperemia;
  • swelling.

In the case of primary chronic version, the symptoms can follow a person years and is expressed as:

  • increase in cervical lymph nodes;
  • hyperthermia;
  • weakness.

In the acute stage of the above symptoms are added:

  • inflammation of the brain and subsequent swelling;
  • to prevent the condition, fades into a coma.

American trypanosomiasis

After being bitten by this bug poop into the wound, feces contain parasites that enter through the skin into the human body, because the bitten place associated with intense itching and itching person.

The site of the bite formed a focus of infection, with a diameter of 15 cm and accompanied by redness and swelling. After the completion of the incubation period, which manifested the first symptoms of the disease:

  • fever;
  • migraine;
  • vomiting;
  • pain in the heart.

The disease leads to CNS (Central nervous system) and ANS (autonomic nervous system), degenerative changes in the heart, the esophagus, the liver and the adrenal glands.


Great perspective, the primary diagnosis of trypanosomiasis is the collection of anamnesis to identify the risk of infection (recent travel in Africa and Latin America, the presence of primary symptoms).

More detailed diagnostic measures resorted to deep research:

  • xenodiagnosis;
  • biological samples (blood, intended for the introduction of the patient into the abdominal cavity of experimental animals);
  • sero-diagnosis;
  • immunological reactions (in the chronic form of Chagas disease in the blood has been detected in serum immunoglobulin G: no acute – M);
  • a lumbar puncture;
  • study of the punctate of lymph nodes, blood.

Diseases caused by parasites are often disguised as other diseases, so you need to own a number of independent research in a precise infestation.


Vaccination against the attack of pathogenic micro-organisms is not provided.

Measures of prevention are:

  • the destruction of the carriers of parasites;
  • a thorough study of the donor blood;
  • timely processing of housing insects solutions;
  • improve the quality of life of the population in poor areas with the habitat of insect vectors.

In addition to the obvious measures to maintain hygiene use products, as well as the above precautionary measures, med. institutions are required to do educational work among the population. Must be available to convey to all segments of society, what is the parasite that causes the disease, and what the impacts are.

To protect themselves from infection with these parasites is impossible. Keep this in mind when you decide to go on a tourist trip to Latin America or Africa.

diagnosis and treatment

Do not neglect precautions, even if you think that they are not effective or there is no danger.