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 species of worms in the world that are dangerous for humans. Their prevalence varies by country and depends on the level of health culture of the population and the socio-economic development of the region. But even in enlightened European countries, symptoms of helminthiasis are found in a third of the population. Worm larvae can enter the human body in different ways, depending on their growth cycle. The names of worms in humans, their varieties, as well as methods of infection, symptoms and methods of treatment of helminthiasis are information relevant to the majority of the world's population.
What kinds of worms are there?
During many years of evolution, parasites have been 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 may be completely absent or mildis expressed.
Worms are able to penetrate the body unnoticed, camouflage 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 vary from tiny to giant sizes (15 meters or more in length). About three dozen parasites are common, including protozoan single-celled creatures. Among all the diversity, there are 3 main groups of helminths according to the characteristics of their life cycle:
- Contact worms- found only in humans, have a simple growth cycle that does not require more than one host. Typical representatives are pinworms; these are the most common intestinal worms in children. Infection occurs in families, children's groups, public places from unwashed hands, household items (toys, books, curtains, etc. ) on which mature eggs of these worms have fallen, as well as through inhalation of dust.
- Group of geohelminths– their eggs must first mature 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 complex life cycle with host change. These worms appear in humans by eating poorly washed vegetables or raw water (echinococcus), animal meat infected with larvae (cattle or pork tapeworm), planed fish and caviar (broad tapeworm), river fish (fluke or liver fluke), or throughblood circulation (filaria).
Types of worms
All types of helminths are divided into 3 categories according to their 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 worm) to 40 cm (ascaris).
- Class of trematodes (commonly called blisters)– Siberian fluke (cat fluke), schistosomes. They are always biohelminths and hermaphrodites, equipped with various apparatus for sucking and attaching to organs within an individual.
- Class Cestodes (type of flatworms)- These are long tape parasites. These include the broad tapeworm, pork and beefworm - this is the largest worm, capable of growing up to 20 meters in length. Flatworms feed on the entire surface of the body, are hermaphrodite and biohelminthic. Echinococcus is considered the smallest representative of cestodes.
What the world of worms is all about is great diversity and exceptional 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 prolific 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 tissues and even in the eyeballs.
Worms can be long-lived; for example, a cysticercus can live in the brain for many years; the development of an aqueous cyst continues for up to 10 years.
About roundworms
Which worms are most common:
- Pinworms- 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 enterobiosis in humans - itching. Transmission of worms between people occurs through dirty hands (eggs of these worms are very often found under children's fingernails), bedding and household items. Eggs are very light and can be transmitted through the air with dust; they remain viable for up to six months. These are the least toxic of the worms. Human faeces do not contain them; for diagnosis it is necessary to scrape from the perianal region.
- Ascaris- a large worm with a curved hook-shaped end; a mature individual can reach a length of up to half a meter. Eggs mature in the soil and enter the stomach and small intestine with unwashed berries, vegetables or herbs. The released larvae gnaw the intestinal wall, penetrating the venous hepatic 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, the sputum with the larvae enters the mouth and is swallowed again in the gastrointestinal tract, where mature individuals develop that lay eggs after a month. These worms are brown or reddish in color because they invade red blood cells. The life span of the roundworm is up to 2 years. For diagnosis, stool is checked for worm eggs.
- Whip- a thin worm, about 5 cm long with a pointed end, with which it attaches to the inner surface of the intestinal wall. The eggs mature in the soil, from where they penetrate the intestines and the larvae emerge here. Flagella feed on blood and like to lodge inside the cecum and appendix, often causing inflammation and anemia. Life expectancy is about 3-4 years. To detect it, you need to check your stool for worm eggs.
- Trichinella- a small round worm that moves between predators and animals. A person becomes infected by eating meat with larvae; in the intestines, after a few days, a mature Trichinella individual is formed, which then gives birth to live larvae. Through the blood they can infect the whole body, but they prefer skeletal muscles, where they remain for up to 5 years.
About tapeworms and tires
What types of worms cause the most damage to the human body:
- Bullworm (commonly called tapeworm)- it is considered the largest worm in humans (up to 15-20 meters) with a body in the form of a ribbon of thousands of individual segments, among which the most mature ones are located in the tail and fall off as the eggs in them mature. These fragments are the size of a human fingernail, fall on the ground, in the grass and then end up in the cattle's body. A person becomes infected through the meat of cows. Bovine tapeworms can live in a person's small intestine for up to 10 years; they feed on the entire surface of their body. For the diagnosis, the feces are examined.
- Pig movie– similar to bull tape, but shorter in length. If a person is infected with larvae, tapeworms develop in their small intestine; when infected with eggs, the larvae migrate and can infect any organ.
- Wide film– their worm type is flat, more than 12 meters long. A person becomes infected by eating poorly salted caviar, dried or undercooked fish. It can settle in the small intestine for decades, constantly releasing mature sections 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 different organs and reach 10 cm or more in diameter. Infection occurs from dogs or sick animals. The course is characterized by a strong clinical picture and risk of complications.
- Feline (liver) puncture- a small worm that enters the human body by consuming undercooked freshwater fish, lives in the lumen of the small intestine, in the bile and pancreatic ducts, can multiply rapidly and live up to two decades.
Despite the wide variety of species, it is possible to accurately determine which worm lives in the human body using modern diagnostic methods and the old proven test - feces for helminth eggs.
Treatment is carried out after confirmation of the diagnosis and prescription of the attending physician.