It has become customary to call human parasites all living organisms at its expense. These are bacteria, fungi, worms. Human parasites are divided into internal and external. The most unpleasant and cause the greatest destruction of the body are helminths - various parasitic worms.
Parasites and the human body
Parasitic creatures on the human body can be external or internal. Exterior includes:
- Mosquitoes.
- Leeches.
- Lice.
- Microorganisms that cause scabies.
But there are more beings who prefer to settle in the body. This includes:
- Bacteria.
- The easiest.
- Helminths.
- Fungus.
The external and internal organization of parasites belong to the simplest. Since they don’t have to evolve to survive, their organization is simplified.
There are many beings that prefer to settle in the body. For example, it can be bacteria.
They cannot survive without the host organism, as they cannot obtain food on their own. But it all multiplies, almost without exception, very quickly, especially in the right circumstances. Where they were not immediately expelled.
They differ geographically. Some of them can be found everywhere, no climate is a barrier for them. Others live exclusively in tropical countries, but on the human body they can be easily carried to any other person. In the body, they also settle in different places.
The luminal parasite is satisfied with the hollow part of the body, and the tissues live inside the tissue.
The developmental cycle of parasites, especially helminths, also varies. Some first grow in the soil (biohelminths), and then migrate to living things. Others need to develop first in the bodies of other living beings, but not a person. Still others in adulthood can be transmitted to others or infect themselves.
It is wrong to assume that infection can occur exclusively through dirty hands. The eggs of some helminths can live outside the nutrient medium for six months and attach well to the animal’s hair. Eggs can also survive in an environment that is dangerous for them - if you cook meat or fish improperly, the whole worm can settle inside you.
It is advisable to cook the meat improperly, because the whole worm can settle inside 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 localization. Endoparasites are:
- Endoparasites of internal organs in contact with the external environment.
They settle precisely in the organs connected to the external environment, not the other way around: parasitic organisms do not choose to "breathe". These organs include the intestines, lungs, and human urinary reproductive system. These are amoebae, worms and parasitic flagelles.
- Blood parasites.
They live in human blood. They can live in plasma, white blood cells, erythrocytes. These are trypanosomes, microfilariae or hemosporidia.
- Tissue endoparasites.
Endoparasites that choose body tissues as their habitat. Muscle tissue, brain, cartilage, connective tissue. Even on nerve fibers, tissue endoparasitis can settle. These are Finnish tapeworms, trypanosomes, myxosporidia, trichina and others.
Endoparasites can choose the brain as their abode.
The definition of the type of parasite according to its localization is rather arbitrary. Many species are able to migrate through various internal organs and travel regularly through the host body. The process of reproduction can take place in one place, and the organism will immediately 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, its life cycle is quite complex.
Some species throughout its life have to change some host, which may belong to different biological species. Others can survive in only one species, but they may need an intermediate host. In one person they reproduce, and in another they grow and mature. With such a complex life cycle, their sexual function increases significantly. To survive in the body, parasites must multiply quickly and in large numbers.
Helminths
There are three main types of helminths, also called worms. Ia:
- Nematodes, they are ringworms.
- Cestode, a ribbon -shaped endoparasite.
- Trematodes, also known as flukes.
Geohelminths began to exist on earth's soil.
Further, they can be divided according to the duration of the life cycle and the number of locations they traverse along the way. There are also three types:
Geohelminths
"Geo" is the earth. These worms begin to exist in the soil of the earth, only after their stage of maturation can infect a person. They do not need an intermediary host; eggs enter the ground along with human feces. Up to the larval stage, they grow exclusively in summer.
Such worms include ringworms, intestinal eels, nekator, whip worms.
These parasitic larvae can enter the human body through unwashed vegetables or direct contact with soil.
Biohelminths
This is a parasitic worm whose life stage passes through several hosts. There are two or more intermediate hosts, depending on the type of worm. Some parasites just change someone. Others, before finally entering the human body, use the organisms of other biological beings for development.
You can be infected through pets or through contact with others, also by eating semi -raw meat. Biohelminths include bovine tapeworms, echinococcus, broad tapeworms, trichina and others.
Worms are contagious
These worms do not need soil or an intermediate host. They go through all stages of their life cycle in one organism, located very comfortably. Larvae are excreted directly from the human body, when in contact with household surfaces and others, they spread freely.
Helminths can live in various organs and systems of the human body, periodically moving 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 test have passed.
Round worms
The most widespread in the human environment are tapeworms, also known as nematodes. In total, there are more than 24 thousand species of nematodes in the world.
The most common human nematode is the ringworm.
They are called round because of their shape, which will be expressed if you make a cross -section. The most common human nematodes:
- Ascaris.
- Cream worms.
- Trichina.
- Vlasoglava.
Helminthic attacks, known as ascariasis, begin with direct contact with worm-infested soil or eating unwashed fruits and vegetables. Parasites begin to grow in the intestines, then enter the human circulatory system, from where they go to various internal organs, heading to the oral cavity. Someone, without realizing this, re -swallows an adult parasite. They eat leftovers that are not digested. Ascaris waste products are highly toxic. There is no vaccine for ascariasis; infection can be prevented only by adhering to the rules of personal hygiene.
A pinworm infection is called enterobiasis. These are small worms (5-10 mm) attached to the intestinal wall. They consume the contents of the blood and intestines. They lay eggs under the skin, coming out of the anus while the owner sleeps. Because of the itching, a person scratches the anal area, the larvae get under the skin and hands, and are easily spread to others at home or in public places. There are no painful symptoms in enterobiasis; it is very problematic to detect a cream worm infection at an early stage.
Trichinella, they are also Trichina, are tapeworms that choose animals or people as their owners.
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 transverse muscles in the body, then they are directed to the small intestine. In case of further infection, there are about 15 thousand Trichina eggs per kilogram of muscle tissue. This parasite is capable of causing a deadly disease, the source of which is named - trichinosis.
The whip worm is so named because of its appearance. The anterior part of their small body is thread -shaped, with one esophagus located in it.
The back is wider, the rest of the internal organs of the parasite are located inside. Whip worms can reach a length of 50 mm. It feeds on blood and tissue fluids. Trichocephalosis causes this disease.
Tape worm
There are about 3. 500 species of tapeworms known worldwide, also called cestodes. These flatworms have no digestive system at all, and the disease they cause is called cestodosis.
The most common cestodosis:
Cysticercosis
The disease is caused by pig tapeworm larvae, which enter through contaminated food, from dirty hands.
The disease affects the skin, bones, internal organs, brain and spinal cord. Most often, parasites are transmitted to the brain (in 60% of cases of infection). It is diagnosed based on the appearance of round formations on the skin. The disease is treated; if an infection of the central nervous system, the prognosis may not be good.
Echinococcosis
It is localized in the liver, lungs, and many other internal organs. Echinococcus larvae evoke this disease. They can develop in a person for several years.
Infection occurs through contact with animals, picking fruits and berries, drinking contaminated water.
The disease is not very noticeable, it can develop over many years, and it turns out that it can only be detected by chance.
Alveococcosis
Alveococcosis is caused by the larvae of alveococcus worms. The disease is similar to echinococcosis, but more severe. Affects the lungs and kidneys. Without treatment, the disease is very likely to be fatal due to the development of liver failure.
Alveococcosis most often attacks the kidneys.
Teniarinhoz
Teniarinhoz is caused by bovine tapeworm. This tapeworm parasite in the human small intestine area, develops over a period of 2. 5-4 months. The prognosis for treatment is often favorable. Parasites can get into a person with inadequately infected or thermally processed raw meat.
Tapeworms are very productive. They have the most reduced sensitivity and no digestive system at all. Such parasites cannot thrive without a host.
Fluke worms
Flukes are fluxes. These are flat worms, their bodies shaped like long tree leaves.
Some species of trematodes can measure up to one and a half meters.
And they end up in the human body most often through fish or other seafood. About 7. 200 species of fluke are known, 40 of which inhabit humans and cause trematodes, a serious disease caused by infection.
The most common abnormalities:
Concussion
Distributed globally, can exist in animals and humans. The biological life cycle is complex, parasites change the host.
The most common coincidence is a liver coincidence.
Schistosoma
Schistosomal larvae can penetrate the skin or mucous membranes. The life cycle is complex, they consume blood. A female is capable of producing about 3000 eggs per day, the fertility of this parasitic worm is very high.
Another lump of liver
They cause opisthorchiasis, a helminthic disease that spreads mostly in the liver. They have toxic effects on the human body.
The digestive system of the fluke worm develops well, and with it the reproductive and excretory systems.
The rest of the system developed poorly. Trematodes feed on blood, skin epithelial cells, and intestinal contents. They can live almost anywhere: from the liver to the conjunctival sac of the eye.
Other types of endoparasites
The remaining internal parasites are various bacteria that cause dangerous diseases, and with them the simplest microorganisms. Fungi that spread in the human body also belong to the endoparasitic section.
Many beneficial and harmful microorganisms live in the human body. Some of them cause diseases that are dangerous enough to cause death. It is not always possible to immediately recognize the presence of a parasitic creature in oneself, but an early diagnosis of an infection provides a better chance for a complete cure. If aggression is suspected, it is recommended to immediately undergo a full examination by a doctor.