Organism which uses as food source and habitat for other organisms, causing them in most cases harm.


Some parasites may use man as a host, what damage they cause to the body, features of diagnostics and tests for parasites, and is there a universal means of parasites, read our article.

The types of parasites

A parasite is a living organism that lives in (endoparasite) or on (ectoparasite) another organism. The parasite can be fixed, obligate, undergoes a complete life cycle, staying in a host (another organism), and to use it only on certain stages, the so-called temporary or facultative parasitism. Some parasites throughout the life cycle of the hosts, starting development in one body and ending in another. This means some parasitic organisms coexist with the host only in a certain period, changing owners or existing independently in the rest of the time, others start and end their life cycle in one body.

The purpose of the introduction of the parasite is to obtain nutrients, security, obtaining the necessary development environment. Parasitic organisms can degrade the quality of life of the owner, to cause irritation, affect the dysfunction, ruin the fabric and also excrete toxins, contributing to the development of diseases. It is believed that the parasites evolyutsioniruet in the direction of decreasing harm to the host organism, thereby extending the opportunity to be at his expense.

In a separate category highlighted parasitoid: as a rule, dipterous or hymenopterous insects lay eggs in the bodies of animals or insects, providing excudant larvae feed. With the birth of the larvae of the host die, becoming food for new parasitant. Their activity is characterized by a combination of parasitism and predation.

Such parasitant include, for example, emerald blattam wasp bites, which is seeking partial paralysis and subordinate behavior of a cockroach. Then the wasp lays eggs in the body of the insect and carries it into the hole. The hatching larvae eat the cockroach. Some insects-parasitoid so to hone skills in parasitism that colonize the host and affect its behavior for a long period. The caterpillars of several species of organisms-the owners of the parasitoid Glyptapanteles (wasp-rider) protect hatched larvae from enemies, while acting as food for them.

Classic parasitism is a special case of symbiosis, the coexistence of two organisms. Such joint residence may be useful to the host and the parasite is harmful to one of the participants or process to happen without much influence. Between different forms of cohabitation, including parasitism, it is sometimes difficult to draw a clear line. For example, some forms of helminths reduce the sensitivity of the human body to allergens, at the same time causing harm and affecting conditionally positively on the health of the owner. Is also known as hirudotherapy, the use of leeches for medical purposes – an ancient form of treatment for various diseases, are used as one of the methods of alternative medicine in the modern world.

types of parasites

Unable to parasitize the bacteria, insects, plants, birds... for Example, cuckoo refers to a type of "nest or egg of a parasite", as it puts eggs in the nests of other birds. The same behaviour have some other types of birds and fish and insects. Certain varieties of plants, such as broomrape, are root parasites that grow on the roots of crops and which are powered at the expense of other plants. Famous chaga mushroom, used in medicine, parasite, growing on the trunk of a birch.

The numerous types of parasites – protozoa, helminths and insects. These parasites in the human body and on its surface are the most common.

Parasites in the human body

Parasites in the human body can be quite varied: the simplest life forms, viruses, fungi, worms, bacteria. In accordance with the classification of viruses (intracellular parasites) and bacteria also belong to the parasitica species, but more often, speaking about parasites in the human body, referring to protozoa and helminths.

Protozoan parasites

For protozoal parasites include the simplest forms of life. Counted 17 species of protozoa that can cause disease in humans. They include such exotic for Russia species as Trypanosoma brucei, portable infected tsetse fly. Trypanosoma brucei causes sleeping sickness or African trypanosomiasis, characterized by confusion, sleep disorders. The disease is mostly found in the tropics of Africa, the Congo basin and Russia is very rare. Amoebiasis which is caused by dysentery amoeba, is the second death master human parasitic disease in the world, it affects every tenth inhabitant of the Earth. The most common is amoebiasis in areas with tropical climate and poor sanitary conditions.

Malaria is also caused by a parasite carried by infected mosquitoes. According to statistics, every year fall ill with malaria to 250 million people.

The most common in the world three types of protozoan parasites – the gout (disease giardiasis), Toxoplasma gondii (toxoplasmosis) and Trichomonas (trichomoniasis).

Giardiasis is a disease of childhood

Giardia has two forms: a movable, or vegetative, and form cysts. Infection occurs by ingestion of cysts that can persist in the environment (soil) up to 3 weeks, and in water up to 5.

Infection occurs most often in young children after licking dirty hands, along with household items, as well as in the use of vegetables, fruits, berries, not subjected to heat treatment. Extended also getting Giardia in the body with contaminated anorum water.

While in the body, moving from Giardia forms cysts in the vegetative and multiply in the small intestine, causing irritation. Special symptoms of giardiasis usually is not evident, limiting such signs, as a violation of stool (diarrhea, constipation), biliary dyskinesia, pain in the upper part of the bellies and the navel, nausea, atopic dermatitis, General malaise. Sometimes there is a lag in weight and height of the child.

When you move from small intestine to large intestine Giardia losing a favorable environment for breeding, again transformirovalsya into cysts and are released into the environment together with feces.

Toxoplasmosis is a dangerous disease in pregnancy

Toxoplasma gondii parasite do that as a temporary host uses felines. Its reproduction is possible only in the intestine of these animals, and most of the groceries are cats. Toxoplasma eggs are excreted in the feces of an infected animal, and can get inside the body of other Pets and farm animals or humans through contact with feces, infected soil, eating raw meat. Toxoplasma gondii belongs to the kind of intracellular parasite, these eubacteria are one of the smallest parasites on Earth.

Cats are the primary host for Toxoplasma, an organism where the parasite spends most of its life cycle. In the bodies of other warm-blooded animals, including man, Toxoplasma gondii spend a short time.

The disease occurs in several forms. In normal immune disease is easily tolerated is manifested by increase in cervical and axillary lymph nodes, periodic low grade fever, muscle aches, General malaise. A mild form of toxoplasmosis spontaneously without requiring specific treatment.

Parasite name

Chronic toxoplasmosis is accompanied by a change in the structure of the eye. The acute form is manifested in a rash, sudden deterioration of health that lead to exhaustion, can result in encephalitis brain. As a rule, to the development of acute toxoplasmosis are those with severe immunodeficiency.

Infection with toxoplasmosis during pregnancy leads to transmission of infectious agents through the placental barrier of the fetus. Toxoplasma in this case cause congenital toxoplasmosis in newborns, which leads to blindness, disorders of the Central nervous system, jaundice , abnormalities of skull bones, mental retardation. Congenital toxoplasmosis in children can occur immediately, symptoms may occur months or years after birth.

The man who was sick with toxoplasmosis develops immunity, defined by the presence of antibodies in the blood. If a pregnant woman has no history of the disease toxoplasmosis during pregnancy she is advised to eliminate contact with cat faeces and avoid places of possible accumulation of rodents.

Trichomoniasis – illness, sexually transmitted diseases

Vaginal Trichomonas Trichomonas vaginalis, the parasite that causes trichomoniasis, one of the most common sexually transmitted diseases which are sexually transmitted. If the disease develops in women affects the vagina. In men, the parasite multiplies in the urethra and affects the function of the prostate gland.

Most often this parasite is transmitted from person to person in the form of vaginal intercourse. Infection via anal, oral sex, or household form is almost excluded, although Trichomonas can exist in a moist environment up to several hours. However, most forms of infection by household, with the exception of sexual contacts are usually the chronic form of hepatitis C were obliterated, acquired by traditional transmission through sexual contact.

The symptoms differ depending on the sex of the patient. Trichomoniasis male usually occurs without obvious symptoms, occasionally accompanied by a discharge from the urethra, pain, burning, clinical picture of inflammation of the prostate gland (prostatitis).

Manifestations of trichomoniasis in women include the following symptoms:

  • vaginal discharge of yellowish color, sometimes accompanied by an unpleasant odor;
  • pain during urination and intercourse;
  • hyperemia (swelling, redness), itching, burning sensation in vulva.

Chronic trichomoniasis may provoke the development of prostatitis in men. For pregnant women the presence of Trichomonas is fraught with premature rupture of membranes, preterm pregnancy.

Helminths, or parasitic worms in the body

Every second on Earth, according to who, each year become infected in one of three basic types of helminths.

According to some, 99% of people are infected with parasites. However, serious research, in particular, based on analyses of patients of clinics and hospitals, did not confirm these figures.

Some parasites helminths belong to? It tapeworms (second name – cestodes) and flukes (trematodes) and round worms, nematodes.

Parasitic worms that may exist in various organisms: animals, birds, fish, plants. Here are the most common worms that affect the human body.

One of the famous exotic helminths, mention of which has reached us since the days of Ancient Egypt, bears the name of Brugia malayi. This round worm of the genus filarias, which causes elephantine disease. Elephantiasis, elefantes is a disease that is characterized by constant stagnation of lymph, severe swelling of various body parts.

Diseased limbs (often the legs, although common and ivory scrotum) covered with warts, ulcers and significantly increase in size. Similarities of the affected foot at the advanced stage of disease of the elephant's feet was the reason for the choice of the name of the disease.

The most commonly filariasis or elephant disease is common in the tropics. Vector mosquitoes are infected with filarias.

All parasitic worms at a certain stage of development leaving the body is the main host for the sake of temporary existence in the external environment or in the body of an intermediate host.

Depending on the transmission path allocate classification of disease vectors:

  • mechanical type carrier has in mind only the movement of the parasite at a certain distance. For example, flies and birds on the limbs can transport helminth eggs in a new environment;
  • a specific kind of carrier means providing the parasite with food or conditions of life, however, this host is temporary. For example, Echinococcus that exists in the human body, as a permanent host chooses the kind of animal dogs (dogs, jackals, wolves), and man (and some types of agricultural, domestic and wild animals) in this case is a carrier of a specific type.
The human parasite

Hydatid disease is a dangerous parasitic disease. The infection is transmitted to man occurs by the dispersion of cysts from the feces of an infected animal. If the area is infected, the pathogen can spread with wind gusts getting into the housing and settling on the already processed food or clean utensils. The most dangerous areas close to pastures, agricultural enterprises, slaughterhouses, which are in the region of high risk of infection.

The type of transmission isolated contact (when the parasite is introduced into the body through the skin or mucous integument) and food that provides the pathogen enters the body, along with the ingestion of food or water.