Worms or helminths are parasites that live, feed, grow and reproduce in the human body, in other words, they use it to carry out their life cycle. According to various statistics, there are from 300 to 500 types of worms in the world that are dangerous for humans. Their prevalence varies by country and depends on the level of sanitary culture of the population and the socio-economic development of the region. But even in educated European countries, the symptoms of helminthiasis are found in one third of the inhabitants. Worm larvae can enter the human body in different ways, depending on their development cycle. The names of worms in humans, their varieties, as well as methods of infection, symptoms and methods of treatment of helminthiasis are information that is important for the majority of the world's population.
What types of worms are there?
Over many years of evolution, parasites are ideally adapted to live at the expense of other living beings, without arousing suspicion in the immune system for a long time, so the symptoms of worms in humans do not appear immediately and may be absentfully or mildly. expressed.
Worms are able to penetrate the body unnoticed, camouflage, destroy tissues and organs and poison the human body with toxins, living in it for a long time.
Some types of worms are dangerous only to humans, while others are parasitic on animals. Their sizes vary from microscopic to gigantic (15 or more meters in length). About three dozen parasites are common, including single-celled protozoan creatures. Among all the diversity, there are 3 main groups of helminths depending on the characteristics of their life cycle:
- Contact worms- found only in humans, have a simple developmental cycle that requires no more than one host. Typical representatives are tapeworms; these are the most common intestinal worms in children. Infection occurs in families, groups of children, public places through unwashed hands, household items (toys, books, curtains, etc. ) on which the ripe eggs of these worms have fallen, as well as through inhalation of dust.
- The group of geohelminths– their eggs must first be laid in soil, water or sand. They enter the human body through the mouth with unwashed berries, vegetables or herbs (such as roundworms and whipworms) or through the skin (such as hookworms).
- Biohelminths– have a complicated life cycle with changing hosts. These worms appear in humans by eating poorly washed vegetables or raw water (echinococcus), animal meat contaminated with larvae (beef or pork tapeworm), planed fish and caviar (broad tapeworm), river fish (fluke orliver) or through the bloodstream. (filaria).
Types of worms
All types of helminths are divided into 3 classes according to morphological characteristics:
- Class Nematode (roundworms)– roundworms, pinworms, hookworms, whipworms, trichinella. Roundworms are distinguished by the presence of separate sexes and have different sizes - from 1 cm (female roundworm) to 40 cm (ascaris).
- Class trematodes (they are commonly called flukes)– Siberian fluke (cat fluke), schistosome. They are always biohelminths and hermaphrodites, equipped with various devices for sucking and sticking to the organs inside a person.
- Class Cestodes (type of flatworms)- These are long tapeworms. These include the broad tapeworm, the pig and cattle tapeworm - this is the largest worm, capable of growing up to 20 meters in length. Flatworms feed on the entire surface of the body, are hermaphrodites and biohelminths. Echinococcus is considered the smallest representative of cestodes.
What the world of worms is all about is great diversity and remarkable survival. The class of trematodes and cestodes are 100% parasites, but roundworms are heterogeneous, there are several tens of thousands of species, but not all of them like to parasitize the human body. Most helminths lay eggs that can survive in the external environment for several months, and Trichinella is a living individual..
In the human body, worms live not only in the intestines, some of them prefer to settle in the liver, pulmonary parenchyma, brain, skin, muscle tissue and even in the eyeballs.
Worms can be long-lived; for example, a cysticerc can live in the brain for many years; the growth of a hydatid cyst continues for up to 10 years.
About roundworms
Which worms are most common:
- Red worms- live in the lower parts of the small intestine and throughout the large intestine of humans; females lay eggs around the anus at night, causing a characteristic sign of enterobiasis in humans - itching. The transmission of worms between people occurs through dirty hands (the eggs of these worms are very often found under children's nails), bedding and household items. Eggs are very light and can be transmitted through dusty air; they remain stable for up to six months. These are the least toxic worms. Human feces do not contain them; for diagnosis it is necessary to make an itch from the perianal area.
- Ascaris- a large worm with a curved end in the shape of a hook; a mature individual can reach a length of up to half a meter. Eggs ripen in soil and enter the stomach and small intestine with unwashed berries, vegetables or herbs. The released larvae gnaw through the intestinal wall, penetrating the venous liver vessels, from there, with the blood flow, they rush to the lungs, the right parts of the heart, sometimes the brain and eyes, and inflammation develops in these organs. During coughing, saliva with larvae enters the mouth and is swallowed back into the gastrointestinal tract, where mature individuals develop, releasing eggs after a month. These worms are brown or reddish in color because they grab red blood cells. The lifespan of a roundworm is up to 2 years. For diagnosis, stool is tested for worm eggs.
- The whipworm- a hair-thin worm, about 5 cm long with a sharp end, with which it attaches to the inner surface of the intestinal wall. The eggs mature in the soil, from where they penetrate into the intestines, where the larvae emerge. Whipworms feed on blood and like to stay inside the cecum and appendix, often causing inflammation and anemia. Life expectancy is about 3-4 years. To find out, you need to test your stool for worm eggs.
- Trichinella- a small round worm that moves between predators and livestock. A person becomes infected by eating meat with larvae; in the intestines, after a couple of days, a mature individual of Trichinella is formed, which then gives birth to live larvae. Through the blood, they can infect the whole body, but they prefer the skeletal muscles, where they stay for up to 5 years.
About tapeworms and fluxes
What types of worms cause the most damage to the human body:
- Bull bar (popularly called bar)- is considered the largest worm in humans (up to 15-20 meters) with a body in the form of a strip of thousands of individual segments, among which the most mature are in the tail and fall as the eggs in them mature. These pieces are the size of a human fingernail, fall on the ground, grass and then end up in the body of cattle. A person becomes infected through cow meat. Bovine tapeworm can live in a person's small intestine for up to 10 years; it feeds on the entire surface of its body. For diagnosis, feces are examined.
- Pork loin– similar to a bull tapeworm, but shorter in length. If a person becomes infected with larvae, the tapeworm grows in his small intestine; when infected by the eggs, the larvae migrate and can infect any organ.
- Wide band– their type of worm is flat, more than 12 meters long. A person becomes infected by eating lightly salted caviar, dried or undercooked fish. It can settle in the small intestine for decades, constantly releasing mature segments with larvae into the environment.
- Echinococcus- the smallest parasite of the cestode class. Over several years, its larvae form cysts, which can be located in various organs and reach 10 cm or more in diameter. Infection occurs from sick dogs or animals. The course is characterized by a pronounced clinical picture and the risk of complications.
- Cat luck (liver).- a small worm that enters the human body by consuming poorly cooked freshwater fish, lives in the lumen of the small intestine, within the bile and pancreatic ducts, can multiply quickly and live up to two decades.
Despite the wide variety of species, it is possible to determine quite accurately which worm lives in the human body using modern diagnostic methods and the old proven test - feces for helminth eggs.
The treatment is carried out after confirmation of the diagnosis and the recommendation of the attending physician.