Protozoan parasites of the human species and the resulting disease

Over the millions of years that have passed since the appearance of the first living organism, the majority of protozoa have not changed. But learned to adapt to the new environment and find ways to survive. One of the most obvious ways for the existence of these organisms has become a parasitism, including in the human body.


What are protozoan parasites of man

The human body, like the body is any more or less a large animal is for parasitic forms of life very attractive. But the simplest, in the human body can live multicellular parasites (helminths).

Place of residence the simplest form may be endogenous (lives inside of the human body) or exogenous. Sometimes, the development of the parasites move around the body, choosing the most appropriate for a certain stage of development habitat.

The microscopic size and the presence of primitive structures allow a simple parasite can successfully survive and reproduce in the most difficult conditions. For all members of this type are characterized by the building that consists of a single cell, filled with cytoplasm – intracellular fluid, which flows all the metabolic processes with the involvement of the organelles (structures that perform various functions to sustain life)

Motion functions can be performed with a designated flagella, cilia. The main process (power) is carried out in several ways:

  • cellular ingestion by mouth;
  • flow;
  • suction surface membranes.

Adverse conditions can be a signal for the formation of cyst – resistant to the external environment of the shells. They need simple human parasites to move from one host to another and can save the prisoner inside of the parasite to several years.

protozoan parasite

The cyst reproduction characterized by the formation of a thin provisional shell required a simple for a short period of division.

Important! Protozoan parasites are the causative agents of protozoal infections: giardiasis, trichomoniasis, sleeping sickness, amoebic dysentery, malaria etc.

The types of protozoa parasites

According to the method of reproduction and movement, the nature of the power there are 4 main classes of protozoa parasites of man.

Important! Primitive structure, the formation of cysts, the simplest method of propagation, microscopic in size – all these factors allow the easiest parasites to penetrate into the protected tissue of the human body and no adverse effects to be a source of serious and sometimes difficult to diagnose pathological conditions.

What diseases caused by protozoa parasites

To diseases caused by protozoan parasites, are such as.


The main symptoms – bouts of fever, joint pain, vomiting, anemia, convulsions. There may be enlargement of the spleen. Malaria, characterized by recurrent course of the disease, with periods of rest and exacerbation. Depending on the type of pathogen distinguish shapes: a three-day, four-day and tropical. The disease is prevalent in Africa and South Asia. For many centuries, as today, the main treatment for quinine remains the drug that is made from the bark of the Cinchona tree. Despite the creation of synthetic analogues, fatal cases when the infection happens in areas without access to modern medical care.

Amoebiasis (dysentery amoebiasis)

The simplest is called the parasite – amoeba dysentery class. Infection can wear intestinal(development in the liver). Within 7-10 days after infection the first symptoms appear: abdominal pain, weakness, subfebrile temperature (up to +37,5⁰). About 10% may appear severe diarrhea, with blood and mucus. Every third infected develops a fever. Characterized by enlargement of the liver and, in some cases, liver abscess. If treatment is not started in time, prolonged diarrhea causes dehydration, weakness and exhaustion of the patient. The outbreak is typical for countries with a hot climate.


The disease is caused by a parasite from the class of flagellates. The main symptoms in cutaneous and Muco-cutaneous leishmaniasis, the lesions of the skin in the form of ulcers. At the Muco-cutaneous form may cause swelling and deformation. If the process involved the respiratory tract, and in rare cases can be fatal. For the visceral form is characterized by enlargement of the liver and spleen, fever and anaemia. The disease is spread in 88 countries, mostly tropical and subtropical climates.


the form of the parasite

The disease is caused by Trichomonas – a parasite from the class of flagellates. The defeat exposed the genitourinary system. The major symptoms in women are itching and burning, redness of the external genitalia, the presence of discharge with an unpleasant odor, sometimes you may experience discomfort during sexual intercourse and urinating. Men in the majority of cases the disease is asymptomatic, sometimes there may be pain during urination and discharge, prostatitis symptoms.


Pathogen – a parasite of the class of ciliates. Characteristic symptom is abdominal pain, diarrhea. In acute cases of the disease is possible rise in temperature, signs of intoxication. The infection can be chronic in nature, with intermittent periods of remission and exacerbation. In complicated cases, the possibility of intestinal perforation and peritonitis.


The disease is caused by parasite of the class sporozoa – Gondii. The characteristic symptoms of the disease are lesions of the eyes, nervous system, muscles, heart, lymph node enlargement, liver and spleen. Occurs primarily in the chronic form. Often the primary infection takes place very easily under the guise of conventional SARS. Then forever is an immune system, and further infection is impossible. The greatest danger is to the fetus during pregnancy: if the child survives, with severe lesions of the nervous system, eyes.

Sleeping sickness

The disease is caused by a parasite the simplest class of flagellates. The characteristics of the first stage are fever, headache and joint. 7-20 days followed by a second phase of the disease: is the perception of the world, failures in coordination, numbness, and sleep disturbance. Outbreaks are localized in certain regions of tropical Africa, the place of residence of the main vector – the tsetse fly.

Chagas Disease


Pathogen – a parasite from the class of flagellates. The primary symptoms are fever, swollen lymph nodes, headache, swelling at the site of the bite. In the primary phase the symptoms may be absent, and after 8-12 weeks of 30-40% can start the development of secondary symptoms: enlargement of the ventricles of the heart, extension of the esophagus, increase in the colon. The second stage of the disease may last for 10-30 years after infection. The most widespread infection has got in Latin America.

Important! Most protozoa parasites enter the human body failure to comply with elementary rules of sanitation and personal hygiene.

Ways of infection

Penetration of any micro-organism inside the human body can occur through rooting through the skin or natural openings. For most of those in the environment protozoa parasites methods of infection of a man just four of the most common:

  1. Contact-household. This route of infection becomes available, the simplest organism for violation of the rules of sanitation and personal hygiene. Because most of the microorganisms in the transition from the body of a host organism other can form cysts and is in this state until the time of exposure in a favourable environment, in other words – inside the human. The infection can occur at any time: the use of foreign household items (towel, linen, utensils), hand washing the dirty water (in the reservoir), etc.;
  2. Fecal-oral (giardiasis). In this case, the infection occurs at the exit of the parasite from the intestine with the faeces or vomit. Failure to comply with the rules of hygiene, the parasite gets into water, food or hands of the new owner and penetrates the body. The source of infection may be a poorly washed vegetables and greens, and children's dirty hands after playing in the sandbox or with Pets;
  3. Through contaminated food (toxoplasmosis). The meat of most animals, especially wild, can be protozoan cysts parasites that insufficient heat treatment into the human body. It is also possible infection through milk products that have not passed sanitary control, and raw fish without sufficient heat treatment;
  4. Malaria, sleeping sickness. Infection occurs by transmission of the pathogen through the saliva of the carrier with the bite. The disease is transmitted by infected insects directly into a susceptible organism.

In addition to the main ways of infection infection can occur in several ways, which are much rarer:

  • Transplacental — the penetration of protozoa parasites from an infected mother through the placenta to the fetus;
  • Sex, the infection occurs only through sexual contact.



Prevention of infection with protozoan parasites involves, first and foremost, compliance with all rules of sanitation and hygiene. Elimination of the infestation can be achieved in a reasonable movement of a number of recommendations:

  • Thermal processing of meat, dairy and fish products adequately (compliance with the thermal regime on the technology). Special attention is given to products that have not passed sanitary control;
  • Thorough washing of fruits, vegetables, berries and herbs, preferably boiling water. In case of impossibility of heat treatment, especially for children, it is better to remove the skin;
  • Regular medical examination, especially in cases of suspected infection with protozoan parasites;
  • The commitment to one sex partner and the rejection of drugs;
  • In the prevention of infection from insect bites, you can apply specific measures: use of drugs, the destruction of mosquitoes, mosquito nets and repellents, developing transgenic mosquitoes (resistant to malaria), a vaccine.

Important! Of great importance in preventing any infections including protozoan parasites, is the level of resistance of the organism. After all, when the cyst gets in adverse conditions where it is not enough nutrition or immune cells constantly attack the foreign object, the parasite or die or leave the host body.

There are many products which are natural Immunostimulants (garlic, ginger, broccoli, carrot, green tea) which when balanced use can have a body a great help in boosting immunity.

In addition, some products have a negative impact on the growth and reproduction of protozoa, especially those who settled in the digestive tract: porridge made from rice and pearl barley, dried fruits, baked apples, vegetable oil, steamed vegetables. In the treatment of parasites it is necessary to limit or eliminate products that cause fermentation processes: bread and sugar.

Currently, the pharmaceutical industry offers many expensive medications. However, their effective use can only be reached in combination with preventive measures and the observance of a certain diet, which can consult a qualified technician.

It is not necessary to forget and about folk remedies, proven by many generations. In the case of combination of all methods and techniques under the supervision of a physician in parasites will be very little chance.