Worms or helminths are parasites that live, feed, grow and reproduce in the human body, in other words, 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 to humans. Their distribution is different in individual countries and depends on the level of sanitary culture of the population and the socio-economic development of the region. But even in enlightened European countries, the symptoms of helminthiasis occur 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 relevant to the majority of the world's population.
What kinds of worms are there?
Over many years of evolution, parasites have perfectly adapted to live at the expense of other living beings, without causing suspicion in the immune system for a long time, so the symptoms of worms in humans do not appear immediately and can be completely or slightly absent. expressed.
Worms can imperceptibly penetrate the body, disguise themselves, 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 range from microscopic to gigantic (15 or more meters in length). About three dozen parasites are common, including protozoan unicellular 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 development cycle that does not require more than one host. Typical representatives are pinworms, these are the most common worms in children. Infection occurs in families, children's groups, public places through unwashed hands, household objects (toys, books, curtains, etc. ) on which mature eggs of these worms have fallen, as well as by inhaling dust.
- A group of geohelminths– their eggs must first mature in soil, water or sand. They enter the human body through the mouth with unwashed fruits, vegetables or herbs (such as roundworms and worms) or through the skin (such as hookworms).
- Biohelminths– have a complex 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), grated fish and roe (broad tapeworm), river fish (flounder or liver fluke), orthrough the bloodstream (filariae).
Types of worms
All types of helminths are divided into 3 classes according to morphological characteristics:
- Class nematodes (roundworms)– roundworms, pinworms, hookworms, whipworms, trichinella. Roundworms are distinguished by the presence of separate sexes and have different sizes - from 1 cm (female pinworms) to 40 cm (ascarids).
- Class trematodes (commonly called flukes)– Siberian fluke (cat fluke), schistosomes. They are always biohelminths and hermaphrodites, equipped with various devices for sucking and attaching to organs inside the person.
- Class Cestodes (type of flatworms)- These are parasites with a long band. These include broad tapeworm, pig and beef tapeworm - this is the largest worm capable of reaching 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.
The world of worms represents great diversity and exceptional survival. The class trematodes and cestodes are 100% parasites, but roundworms are heterogeneous, there are several tens of thousands of species, but not all like to parasitize the human body. Most helminths lay eggs that can survive in the external environment for several months, and trichinella is a viviparous individual.
In the human body, worms live not only in the intestines, some of them prefer to be in the liver, lung parenchyma, brain, skin, muscle tissue and even in the eyeballs.
Worms can be long-lived; for example, cysticercosis can live in the brain for many years; hydatid cyst growth continues for up to 10 years.
About roundworms
What worms are the most common:
- Pinworms- live in the lower parts of the small intestine and in the entire large intestine of man; females lay eggs around the anus at night, causing a characteristic sign of enterobiosis in humans - itching. Transmission of worms between people occurs through dirty hands (very often eggs of these worms are found under children's nails), bedding and household items. The eggs are very light and can be transmitted through the air with dust, they remain viable for up to six months. They are the least toxic of the worms. Human feces do not contain them, for diagnosis it is necessary to take a scraping from the perianal area.
- Ascaris- a large worm with a curved hook-shaped end; a mature individual can reach a length of up to half a meter. The eggs mature in the soil and enter the stomach and small intestine with unwashed fruits, vegetables or herbs. The released larvae bite 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 to the brain and eyes, and inflammation develops in these organs. When coughing, sputum with larvae enters the mouth and is swallowed again in the gastrointestinal tract, where mature individuals develop, which lay eggs after a month. These worms are brown or reddish in color because they hijack red blood cells. The life span of roundworms is up to 2 years. For diagnosis, feces are examined for worm eggs.
- Whipworm- a hair-thin worm, about 5 cm long, with a pointed end that clings to the inner surface of the intestinal wall. The eggs mature in the soil, from where they penetrate into the intestine, where the larvae emerge. Whipworms feed on blood and like to stay in the cecum and appendix, often causing inflammation and anemia. The life span is about 3-4 years. To find it, you need to examine 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 few 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 remain for up to 5 years.
For tapeworms and flukes
What types of worms cause the most harm to the human body:
- Tapeworm (commonly called tapeworm)- it is considered the largest worm in man (up to 15-20 meters) with a body in the form of a ribbon of thousands of separate segments, among which the most mature are in the tail and fall while the eggs in them mature. These fragments are the size of a human fingernail, fall on the ground, grass and then end up in the body of livestock. Humans become infected through the meat of cows. The beef tapeworm can live in the small intestine of a person for up to 10 years, feeding on the entire surface of his body. Stools are examined for diagnosis.
- Pork tapeworm– similar to tapeworm, but shorter in length. If a person is infected with larvae, the tapeworm develops in his small intestine, when infected with eggs, the larvae migrate and can infect any organ.
- Broad tapeworm– their type of worm is flat, over 12 meters long. A person becomes infected by eating poorly salted caviar, dried or undercooked fish. It can establish itself 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 that can be located in various organs and reach 10 cm or more in diameter. Infection occurs from dogs or sick cattle. The course is characterized by a pronounced clinical picture and risk of complications.
- Feline (liver) fluke- a small worm that enters the human body through the consumption of poorly processed freshwater fish, lives in the lumen of the small intestine, inside the bile and pancreatic ducts, can multiply rapidly 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 prescription of the attending physician.