It is customary to call all organisms that live at their expense human parasites. These are bacteria, fungi, worms. Human parasites are divided into internal and external. The most unpleasant and causing the most destruction to the body are helminths, a variety of parasitic worms.
Parasites and the human body
Creatures that parasitize the human body can be external or internal. External include:
- Mosquitoes
- Leeches.
- Lice
- Microorganisms that cause scabies.
But there are many more creatures that prefer to settle inside the body. These include:
- Bacteria
- The simplest.
- Helminths.
- Mushrooms.
The external and internal organization of the parasite belongs to the simplest. Due to the fact that they do not need to evolve to survive, their organization is greatly simplified.
There are many creatures that prefer to settle inside the body. For example, they can be bacteria.
They cannot survive without a host organism, as they cannot obtain their own food. But they all multiply, almost without exception, very quickly, especially under the right conditions. Where they are not driven immediately.
They differ geographically. Some can be found everywhere, no climate is an obstacle for them. Others live exclusively in tropical countries, but in the human body they can easily be carried to others. On the body, they are also installed in different places.
Luminal parasites are satisfied with the hollow parts of the body and the tissues live in the tissues.
The development cycles of parasites, mainly helminths, are also varied. Some develop first in the soil (biohelminths) and then move into a living being. Others need to develop first in the body of any other living being, but not in a person. Even others in an adult state can be transferred to another or reinfect oneself.
It is a mistake to assume that 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 an environment that is dangerous for them: if you cook meat or fish incorrectly, a whole litter of worms can settle inside you.
It is worth cooking meat incorrectly, as a whole litter of worms 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 according to location. Endoparasites are:
- Endoparasites of internal organs that connect with the external environment.
They are installed precisely in those organs that are connected to the external environment, not the other way around: the parasitic organism does not choose to "breathe". These organs include the intestines, lungs, and the human urinary reproductive system. These are amoebas, worms, and parasitic flagellates.
- Blood parasites.
They live on 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 a place of residence. Muscle tissue, brain, cartilage, connective tissue. Even in nerve fibers, tissue endoparasitis can settle. These are Finnish tapeworms, trypanosomes, myxosporidia, trichina, and others.
Endoparasites can choose the brain as their place of residence.
The definition of the type of parasite by the place of its location is quite arbitrary. Many species can migrate through various internal organs and travel regularly through the host's body. The reproduction process can take place in one place and organisms will exist directly and feed in another. The place where the parasitic creature sits and will be considered the place of its conditional location.
Despite the simplification of many parasite systems, their life cycle is quite complex.
Some species throughout their life have to change several hosts, which can belong to different biological species. Others can survive within a single species, but may require intermediate hosts. In one person they multiply and in another they develop and mature. With such a complex life cycle, your sexual functions increase significantly. To survive in the body, parasites have to multiply rapidly and greatly.
Helminths
There are three main types of helminths, also called worms. That:
- Nematodes are intestinal worms.
- Cestodes, ribbon-shaped endoparasites.
- Trematodes, also known as trematodes.
The soil-transmitted helminths begin their existence in the soil of the earth.
In addition, they can be divided according to the length of the life cycle and the number of locations they pass through on the road. There are also three types:
Soil-transmitted helminths
"Geo" is the earth. These worms begin their existence in the soil of the earth, only after the maturation stage can they infect a person. They do not need intermediate hosts; the 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, nekator, whipworms.
The larvae of these parasites can enter the human body through unwashed vegetables or through direct contact with the soil.
Biohelminths
These are parasitic worms whose life stages go through multiple hosts. There may be two or more intermediate hosts, depending on the type of worm. Some parasites only change one person. Others, before finally entering the human body, use the organisms of other biological beings for their development.
You can become infected through pets or by contact with other people, as well as by eating undercooked meat. Biohelminths include bovine tapeworms, echinococci, broad tapeworms, trichina, and others.
Contagious worms
These worms do not need soil or intermediate hosts. They go through all the stages of their life cycle in an organism, very comfortably located. The larvae are excreted directly from the human body, when they come into contact with household surfaces and other people, they spread freely.
Helminths can live in different 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 what treatment can be started only after all the necessary tests have been passed to establish the type of tests.
Round worms
The most widespread in the human environment are roundworms, also known as nematodes. In total, there are more than 24 thousand 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.
- Intestinal worms.
- Trichina.
- Vlasoglava.
Helminthic infestation, known as ascariasis, begins with direct contact with worm-infested soil or eating unwashed fruits and vegetables. Parasites begin to develop in the intestines, then enter the human circulatory system, from where they go to various internal organs, heading to the oral cavity. A person, without realizing this, swallows an adult parasite again. They feed on the remains of undigested food. Ascaris waste products are extremely toxic. There is no vaccine for ascariasis; infection can be prevented only by observing the rules of personal hygiene.
Pinworm infection is called enterobiasis. These are small worms (5-10 mm) that adhere to the intestinal walls. They feed on blood and intestinal contents. They lay their eggs under the skin, coming out through the anus while the owner sleeps. Due to itching, a person scratches the anal area, the larvae get under the skin and on the hands, and they can easily be transmitted to other people in the house or in public places. There are no painful symptoms in enterobiasis; it is extremely troublesome to detect pinworm infection in the early stage.
Trichinella, they are also Trichina, are intestinal worms that choose an animal or a person as their owner.
Trichinella is a parasitic worm that infects the human body, causing dangerous trichinosis, a helminthic disease.
They begin to develop in the area of the striated muscles of the body, then they are redirected to the small intestine. In advanced cases of infection, there may be around 15, 000 Trichina eggs per kilogram of muscle tissue. These parasites are capable of causing a deadly disease, named for its origin: trichinosis.
Whipworms are named for their appearance. The front part of its small body is threadlike, with an esophagus located in it.
The back is wider, in it are the rest of the internal organs of the parasite. The whipworm can be up to 50 mm long. It feeds on blood and tissue fluids. Whipworm causes the disease.
You had
There are about 3, 500 known species of tapeworm worldwide, also called cestodes. These flatworms do not have any digestive systems and the diseases they cause are called cestodoses.
The most common cestodoses:
Cysticercosis
The disease is caused by larvae of the pork tapeworm, which enter through contaminated food, from dirty hands.
The disease affects the skin, bones, internal organs, brain, and spinal cord. Very often, parasites are sent to the brain (in 60% of cases of infection). It is diagnosed based on the appearance of rounded formations on the skin. The disease is treated; in case of infection of the central nervous system, the prognosis may be unfavorable.
Echinococcosis
It is located in the liver, lungs, and many other internal organs. Echinococcus larvae excite the disease. They can develop within a person over the course of several years.
The infection occurs by contact with animals, picking berries and fruits, drinking contaminated water.
The course of the disease is not too noticeable, it can develop over the years, and it turns out that it is only detected by chance.
Alveococcosis
Alveococcosis is caused by the larvae of alveococcal worms. The disease is similar to echinococcosis, but it is more serious. 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 often affects the kidneys.
Teniarinhoz
Teniarinhoz is caused by a bovine tapeworm. The tapeworm parasitizes in the human small intestine area, develops over a period of 2. 5 to 4 months. The prognosis of treatment is usually favorable. Parasites can enter a person with infected raw meat or insufficient thermal processing.
Tapeworms are very prolific. They have the lowest remaining sensitivity and have no digestive system. These parasites cannot develop without a host.
Trematode worms
Flukes are flukes. These are flat worms, with the shape of their body that resembles an elongated leaf of a tree.
Some species of flukes can measure up to one and a half meters.
And they end up in the human body most often through fish or other shellfish. About 7, 200 species of flukes are known, 40 of which live in humans and cause flukes, a serious disease caused by infection.
The most common flukes:
Liver parasite
Distributed globally, it can exist in animals and humans. The biological life cycle is complex, the parasite changes host.
The most common coincidence is that of the liver.
Schistosoma
Schistosome larvae can penetrate the skin or mucous membranes. The life cycle is complex, they feed on blood. A female is capable of producing about 3000 eggs per day, the fertility of these parasitic worms is very high.
Other liver flukes
They cause opisthorchiasis, a helminthic disease that spreads mainly in the liver. They have a toxic effect on the human body.
The digestive system of trematode worms is well developed, and with it the reproductive and excretory system.
The rest of the systems are developing poorly. Flukes feed on blood, skin epithelial cells, and intestinal contents. They can live almost anywhere: from the liver to the conjunctivial sacs of the eyes.
Other types of endoparasites
The rest of the internal parasites are a variety of bacteria that cause dangerous diseases, and with them the simplest microorganisms. The fungus that spreads within the human body also belongs to the endoparasite section.
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 within oneself, but early diagnosis of the infection provides a better chance for a complete cure. If an invasion is suspected, it is recommended to immediately undergo a complete examination by a physician.