It is customary 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 unpleasant and causing the greatest destruction of the body are helminths - a variety of parasitic worms.
Parasites and the human body
Beings parasitizing in the human body can be external or internal. External include:
- Mosquitoes.
- Leeches.
- Lice.
- Microorganisms that cause scabies.
But there are many more beings who prefer to settle inside the body. They include:
- Bacteria.
- The simplest.
- Helminths.
- Fungal.
The external and internal organization of the parasite belongs to the simplest. Due to the fact that they do not need to develop for survival, their organization is greatly simplified.
There are many beings who prefer to settle inside the body. For example, it could be bacteria.
They cannot survive without a host organism, as they are unable to obtain their own food. But they all reproduce, almost without exception, very quickly, especially under suitable conditions. Where they don't fight right away.
They differ geographically. Some can be found everywhere, the climate does not bother them. Others live exclusively in tropical countries, but on the human body they can easily be brought to others. In the body, they also settle in different places.
Luminal parasites are happy with the hollow parts of the body, and the tissues live in the tissues.
The development cycles of parasites, mainly helminths, are also diverse. Some first develop in the ground (biohelminths) and then move into a living being. Others must first develop in the body of every other living being, but not of man. Third-aged adults can now be transferred to another or re-infected.
It is wrong to assume that the infection can occur exclusively through dirty hands. The eggs of some helminths are viable outside the nutrient medium for six months and adhere well to animal hair. Eggs also survive in a dangerous environment - if you cook the wrong meat or fish, you can accommodate a whole breed of worms.
It is worth cooking the meat incorrectly, as the whole chicken worms can settle in you.
Human endoparasites
Parasites are divided into endoparasites and ectoparasites. Endoparasites - those that live inside, ecto - outside. Endoparasites are able to settle in almost all internal organs and tissues of the body. They are divided depending on the location. Endoparasites are:
- Endoparasites of internal organs connecting with the external environment.
They are found precisely in those organs that are related to the external environment, not the other way around: the parasitic organism does not choose to "breathe". These organs include the intestines, lungs and human reproductive system. These are amoebae, worms and parasites. bulls.
- 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 that choose body tissues as their habitat. Muscle tissue, brain, cartilage, connective tissue. Even in nerve fibers, the tissue endoparasite can settle. These are the Finnish tapeworms, trypanosomes, myxosporidia, trichinae and others.
Endoparasites can choose the brain as their place of residence.
The definition of the type of parasite at the place of its localization is quite arbitrary. Many species are able to migrate through various internal organs and travel regularly through the host's body. The process of reproduction can take place in one place, and organisms will directly exist and feed in another. The place where the parasitic creature settles and will be considered the place of its conditional localization.
Despite the simplification of many parasitic systems, their life cycle is quite complex.
Some species have to change several hosts throughout their lives, which may belong to different species. Others are able to survive within only one species, but they may require intermediate hosts. In one person they multiply, and in another they develop and mature. With such a complex life cycle, their sexual functions increase significantly. To survive in the body, parasites must multiply rapidly and abundantly.
Helminths
There are three main types of helminths, also called worms. That:
- Nematodes, they are roundworms.
- Cestodes, banded endoparasites.
- Trematodes, also known as flukes.
Geohelminths begin their existence in the earth's soil.
In addition, they can be divided according to the length of the life cycle and the number of places that pass along the way. There are also three types:
Geohelminths
"Geo" is the earth. These worms begin their existence in the earth's soil, only after the stage of maturation they are able to infect humans. They do not need intermediate hosts; eggs enter the soil along with human feces. Up to the larval stage, they develop exclusively during the warm season.
Such worms include roundworms, intestinal eels, some, whips.
The larvae of these parasites can enter the human body through unwashed vegetables or direct contact with the soil.
Biohelminths
These are parasitic worms whose stages of life pass through several hosts. Depending on the type of worm, there may be two or more intermediate hosts. Some parasites only replace humans. Others, before finally entering the human body, use the organisms of other biological beings for development.
You can get infected through pets or through contact with other people, as well as by eating semi-raw meat. Biohelminths include bovine tapeworms, echinococci, tapeworms, trichinae and others.
Infectious worms
These worms need neither soil nor intermediate hosts. They go through all stages of their life cycle in an organism very conveniently located. The larvae are released directly from the human body, when in contact with household surfaces and other people, they spread freely.
Helminths can live in various organs and systems of the human body, periodically 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 only be started after all the tests needed to establish 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 human nematodes:
- Ascaris.
- Oysters.
- Trichina.
- Vlasoglava.
The helminth infection, known as ascariasis, begins with direct contact with worm-infected soil or by eating unwashed fruits and vegetables. The parasites begin to develop in the intestines, after which they enter the human circulatory system, from where they go to various internal organs, heading for the oral cavity. Without realizing it, a person swallows an adult parasite again. They feed on leftovers of undigested food. Ascaris waste products are extremely toxic. There is no vaccine against ascariasis; the infection can be prevented only by following the rules of personal hygiene.
Pinworm infection is called enterobiosis. These are small worms (5-10 mm) that attach to the intestinal walls. They feed on blood and intestinal contents. They lay their eggs under the skin, coming out of the anus while the owner sleeps. Due to the itching, a person scratches the anal area, the larvae get under the skin and on the hands and can be easily transmitted to other people in the house or in public places. In enterobiosis there are no painful symptoms; it is extremely problematic to detect pinworm infection at an early stage.
Trichinella, also known as Trichinella, are roundworms that choose an animal or human as their owner.
Trichinella is a parasitic worm that infects the human body, causing the dangerous worm disease trichinosis.
They begin to develop in the area of striated muscles in the body, after which they are redirected to the small intestine. In advanced cases of infection there may be about 15 thousand eggs of trichina per kilogram of muscle tissue. These parasites are capable of causing a deadly disease named after their source - trichinosis.
The whips are so named because of their appearance. The front of their small body is like a thread in which an esophagus is located.
The posterior part is wider, in it are located the other internal organs of the parasite. The whip can be up to 50 mm long. It feeds on blood and tissue fluid. Trichocephalus causes the disease.
Tapeworms
There are about 3, 500 species of tapeworms in the world, 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 the larvae of the porcine tapeworm, which get inside through contaminated food, from dirty hands.
The disease affects the skin, bones, internal organs, brain and spinal cord. Most often the parasites are 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 case of central nervous system infection, the prognosis may be unfavorable.
Echinococcosis
Localized in the liver, lungs and many other internal organs. Echinococcus larvae cause the disease. They can develop in humans for several years.
Infection occurs through contact with animals, picking fruits and berries, drinking contaminated water.
The course of the disease is not very noticeable, it can develop over the years and it turns out that it is detected only by accident.
Alveococcosis
Alveococcosis is caused by the larvae of alveococcal worms. The disease is similar to echinococcosis, but more severe. It affects the lungs and kidneys. Without treatment, the disease is very likely to be fatal due to the development of liver failure.
Alveococcosis most commonly affects the kidneys.
Teniarinhoz
Teniarinhoz is caused by bovine tapeworm. It parasitizes tapeworm in the small intestine of man, develops over a period of 2, 5-4 months. The prognosis for treatment is often favorable. Parasites can get inside a person with contaminated raw or undercooked meat.
Tapeworms are very fruitful. They have the lowest residual sensitivity and no digestive system at all. Such parasites cannot develop without a host.
Methyl worms
The flukes are flukes. These are flatworms, shaped like elongated leaves on a tree.
Some types of trematodes can be up to one and a half meters in size.
And they get into the human body most often through fish or other seafood. About 7, 200 species of methyl are known, 40 of which inhabit humans and cause trematodes, a serious disease caused by infection.
The most common flukes:
Hepatic methyl
It can exist in animals and humans worldwide. The biological life cycle is complex, the parasite changes hosts.
The most common methyl is hepatic methyl.
Schistosome
Schistosome larvae can penetrate the skin or mucous membranes. The life cycle is complex, they feed on blood. One female is able to produce about 3, 000 eggs a day, the fertility of these parasitic worms is very high.
Other hepatic flukes
They cause opisthorchiasis, a worm disease that spreads mostly to the liver. They have a toxic effect on the human body.
The digestive system of methyl worms is well developed, and with it the reproductive and excretory systems.
The other systems are 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 other internal parasites are a variety of bacteria that cause dangerous diseases, and with them the simplest microorganisms. The fungus that spreads in the human body also belongs to the part of endoparasites.
Many useful 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 yourself, but early diagnosis of the infection gives a greater chance of complete cure. If an invasion is suspected, it is recommended that you undergo a full medical examination immediately.