It is common to call human parasites all organisms that live at their expense. These are bacteria, fungi, worms. Human parasites are divided into internal and external. The most annoying and biggest causes of destruction of the body are helminths - various parasitic worms.
Parasites and the human body
Beings that parasitize on the human body can be external or internal. External include:
- Mosquitoes.
- Leeches.
- Ears.
- Microorganisms that cause scabies.
But there are many more beings who prefer to inhabit the body. These include:
- Bacteria.
- The simplest.
- Helminths.
- Fungal.
The external and internal organization of parasites is among the simplest. Due to the fact that they do not need to evolve to survive, their organization has been greatly simplified.
There are many beings who prefer to inhabit the body. For example, it could be bacteria.
They cannot survive without a host organism because they are unable to get their own food. But they all multiply, almost without exception, very quickly, especially in suitable conditions. Where they are not driven immediately.
They differ geographically. You can find some everywhere, no climate bothers them. Others live exclusively in tropical countries, but on the human body they can easily be brought to anyone else. They also settle in different places in the body.
Luminal parasites are satisfied with hollow parts of the body, and tissues live in tissues.
Cycles of development of parasites, mainly helminths, are also different. Some first develop in the earth (biohelminths) and then move into a living being. Others should first develop in the body of any other living being, but not a person. Others in an adult state can switch to another or become infected again.
It is wrong to assume that infection can only occur with dirty hands. The eggs of some helminths can live outside the nutrient medium for six months and adhere well to animal hair. Eggs also survive in a dangerous environment for them - if you cook meat or fish incorrectly, a whole litter of worms can settle in you.
It is worth cooking the meat wrong, because a whole litter of worms can settle in you.
Human endoparasites
Parasites are divided into endoparasites and ectoparasites. Endoparasites - those that live inside, ecto - outside. Endoparasites can deposit in almost all internal organs and tissues of the body. They are divided depending on the localization. Endoparasites are:
- Endoparasites of internal organs that connect with the external environment.
They are located precisely in those organs that are connected to the external environment, and not vice versa: the parasitic organism does not choose to "breathe". These organs include the intestines, lungs and urinary-reproductive system of man. These are amoebae, worms and parasitic whips.
- Blood parasites.
They live in human blood. They can live in plasma, white blood cells, erythrocytes. These are trypanosomes, microfilariae or hemosporidia.
- Tissue endoparasites.
Those endoparasites who choose body tissues for their residence. Muscle tissue, brain, cartilage, connective tissue. Even in nerve fibers, tissue endoparasitis can settle. These are Finnish tapeworms, trypanosomes, myxosporidia, Trichinella and others.
Endoparasites can choose the brain for their residence.
The definition of the type of parasite by the place of its localization is quite arbitrary. Many species can migrate through various internal organs and travel regularly through the host’s body. The process of reproduction can take place in one place, and the organisms will directly exist and feed in another. The place of origin of the parasitic being will be considered the place of its conditional localization.
Despite the simplification of many parasitic systems, their life cycle is quite complex.
Some species must change several hosts during their lifetime, which may belong to different species. Others may survive within only one species, but may need intermediate hosts. In one person they multiply, and in another they develop and mature. With such a complex life cycle, their sexual functions are significantly increased. In order to survive in the body, parasites must multiply rapidly and abundantly.
Helminths
There are three main types of helminths, which are also called worms. It:
- Nematodes, they are roundworms.
- Cestodes, endoparasites in the form of a strip.
- Trematodes, also known as flukes.
Geohelminths begin their existence in the earth's soil.
Furthermore, they can be divided according to the duration of the life cycle and the number of locations passing through. There are also three types:
Geohelminths
"Geo" is earth. These worms begin their existence in the earth, only after the maturation phase can they infect man. They do not need indirect hosts; eggs enter the soil along with human feces. Until the larval stage, they develop exclusively in the warm season.
Such worms include roundworms, intestinal eels, nectar, bicher.
The larvae of these parasites can enter the human body with unwashed vegetables or direct contact with the soil.
Biohelminths
These are parasitic worms whose life stage passes through several hosts. They can be two or more intermediate hosts, depending on the type of worm. Some parasites only change a person. Others, before they finally enter the human body, use the organisms of other biological beings for development.
You can become infected with pets or contact with other people, as well as eating semi-raw meat. Biohelminths include bovine tapeworms, echinococci, broadworms, trichinae and others.
Infectious worms
These worms do not need soil or temporary hosts. They go through all the phases of their life cycle in one organism, very comfortably located. The larvae are excreted directly from the human body, when they come in contact with household surfaces and other people, they spread freely.
Helminths can live in various organs and systems of the human body, occasionally migrating from one part of the body to another.
The list of diseases caused by helminths is very extensive. It is possible to determine which parasites live in the body and which treatment can be started only after all the tests necessary to determine the type of tests have been passed.
Roundworms
The most common in the human environment are roundworms, also known as nematodes. In total, there are more than 24, 000 species of nematodes in the world.
The most common human nematodes are roundworms.
They are called round because of their shape, which is revealed if you make a cross section. The most common nematodes in humans:
- Ascaris.
- Pinworms.
- Trichina.
- Vlasoglava.
The helminthic infection, known as ascariasis, begins with direct contact with soil infected with worms or by eating unwashed fruits and vegetables. The parasites begin to develop in the intestines and then enter the human circulatory system, from where they go to various internal organs, leading to the oral cavity. The person, without noticing it, swallows the already adult parasite again. They feed on the remains of undigested food. Ascaris waste products are extremely toxic. There is no vaccine against ascariasis; infection can be prevented only by following the rules of personal hygiene.
Pinworm infection is called enterobiasis. These are small worms (5-10 mm) that attach to the intestinal walls. They feed on blood and intestinal contents. The eggs are laid under the skin, coming out of the anus while the owner sleeps. Because of the itching, people scratch the anus area, the larvae enter under the skin and on the hands and can be easily transmitted to other people in the house or in public places. Enterobiasis has no painful symptoms; it is extremely problematic to detect pinworm infection at an early stage.
Trichinella, they are also Trichinella, are roundworms that choose an animal or person as their owner.
Trichinella is a parasitic worm that infects the human body causing the dangerous helminthic disease trichinosis.
They begin to develop in the area of the striated muscles in the body and then redirect to the small intestine. In advanced cases of infection, there can be about 15 thousand trichina eggs per kilogram of muscle tissue. These parasites are capable of causing a deadly disease, named after its source - trichinosis.
Whips are so named because of their appearance. The front of their small body is thread-like, and there is one esophagus in it.
The posterior part is wider, it contains other internal organs of the parasite. The whip can be up to 50 mm long. It feeds on blood and tissue fluid. Trichocephaly causes the disease.
Ribbons
There are about 3, 500 known species of tapeworms worldwide, also called cestodes. These flatworms have no digestive system at all, and the diseases they cause are called cestodes.
The most common cestodes:
Cysticercosis
The disease is caused by swine tapeworm larvae, which enter through contaminated food with dirty hands.
The disease affects the skin, bones, internal organs, brain and spinal cord. Parasites are most often sent to the brain (in 60% of cases of infection). It is diagnosed on the basis of the appearance of rounded formations on the skin. The disease is treatable; in the case of a central nervous system infection, the prognosis may be unfavorable.
Echinococcosis
It is localized in the liver, lungs and many other internal organs. Echinococcus larvae cause disease. They can develop in humans over several years.
Infection occurs through contact with animals, picking berries and fruits, drinking contaminated water.
The course of the disease is not too noticeable, it can develop with age, and it turns out that it is detected only by chance.
Alveococcosis
Alveococcosis is caused by the larvae of alveococcal worms. The disease is similar to echinococcosis, but it is more severe. It affects the lungs and kidneys. Without treatment, it is very likely that the disease will be fatal due to the development of liver failure.
Alveococcosis most commonly affects the kidneys.
Teniarinhoz
Teniarinhosis is caused by bovine tapeworm. It parasitizes on tapeworms in the area of the small intestine of man, develops over a period of 2, 5-4 months. The prognosis for treatment is often favorable. Parasites can enter a person with infected raw or undercooked meat.
The tapeworms are very fertile. They have the least reduced residual sensitivity and have no digestive system at all. Such parasites cannot develop without a host.
Fluke worms
Butterflies are fluffy. These are flatworms, which in the shape of the body resemble an oblong leaf of a tree.
Some types of trematodes can be up to one and a half meters long.
And in the human body they end up most often through fish or other seafood. About 7, 200 species of flukes are known, 40 of which inhabit humans and cause trematodes, a serious disease caused by infection.
The most common flukes:
Liver fluke
Globally distributed, it can exist in animals and humans. The biological life cycle is complex, the parasite changes hosts.
The most common is fluke.
Schistosoma
Schistosome larvae can penetrate the skin or mucous membranes. The life cycle is complex, they feed on blood. One female can produce about 3000 eggs a day, the fertility of these parasitic worms is very high.
Other liver flukes
They cause opisthorchiasis, a helminthic disease that mainly spreads to the liver. They are toxic to the human body.
The digestive system of the fluke worm is well developed, and with it the reproductive and excretory system.
The rest of the system is poorly developed. Trematodes feed on blood, skin epithelial cells, and intestinal contents. They can live almost anywhere: from the liver to the conjunctival sacs of the eyes.
Other types of endoparasites
The rest of the internal parasites are various bacteria that cause dangerous diseases, and with them the simplest microorganisms. The fungus that spreads inside the human body also belongs to the part of the endoparasite.
Many beneficial and harmful microorganisms live in the human body. Some of them cause quite dangerous diseases that can lead to death. It is not always possible to immediately recognize the presence of parasitic creatures in oneself, but early diagnosis of the infection gives a better chance of complete cure. If an invasion is suspected, it is recommended to undergo a thorough examination by a doctor immediately.