The most common types of worms in humans

Various types of worms are found everywhere, with children accounting for 80% of those affected.Helminths or worms (from the Greek parasitic worm) are lower worms that parasitize the bodies of humans and animals.They cause pathologies called helminthiasis.According to the WHO, every year 50% of the population is infected with: pinworms (1.2 billion people), hookworms (900 million) and whipworms (up to 700 million).

What types of worms are there?To date, more than 400 species of worms found in humans have been identified.All types of human worms are divided into 2 large groups: flat and round (nematodes).In turn, flatworms are divided into tapeworms (cestodes) and worms (trematodes).Cestodes are also divided into tapeworms and tapeworms.

The opinion that human worms live only in the intestines is a mistake;they can migrate with the bloodstream throughout the body and settle in various places.All types of parasitic worms feed at the expense of their host and use it in their life cycle.

Circulation of worms in nature

To preserve their species, parasites must constantly move to the external environment, leaving their host, and establish themselves in the bodies of animals, using them as intermediate hosts.In this process, transporters are of great importance: mechanical - these can be insects that carry worms over long distances on their legs.Worms do not live in insect bodies.

A specific carrier or intermediate host - in it the parasites go through only one of their development cycles.When circulating, the method of transmission of worms is important:

• contact - penetration through intact skin and mucous membranes (hookworm);
• nutritional.

Peculiarities of worm reproduction

Most often, lower worms are hermaphrodites, but there are also worms with gender differences - nematodes.If helminths change several hosts during their development cycle (sometimes up to 4), they are called biohelminths.If they live with just one owner, they are geohelminths.

Worm development stages:

1. Egg stages - the female lays immature eggs, which mature in the external environment and then return to humans orally.
2. The second stage is when a larva hatches from the egg.This process takes place in the gastrointestinal tract.It migrates throughout the body in search of an ideal habitat.After finding him, he continues to develop until he becomes an adult.
3. The third stage is the adult, which again lays eggs.It should be noted that worms do not develop in all organisms, but only in those that are suitable for them, that is, for example, larvae, the host of which is an ungulate, will survive if they enter the body of a predator, but will not lay eggs there.

Types of helminthiasis

The types of helminths in humans are divided according to their habitat: luminal and tissue.In the first case, parasites live in the lumen of hollow organs, most often the intestines: ascariasis, trichuriasis, strongyloidiasis, teniarhinchiasis and others.Tissues live in the thickness of various organs and tissues.What organs can be affected by worms?They can settle and affect the hepatobiliary system, brain, eyes, lymph nodes, lungs, which is why the diseases can have several names:

• for liver damage - echinococcosis;
• brain damage - cysticercosis;
• lymph nodes - filariasis;
• pulmonary helminthiasis - paragonimiasis;
• tissue helminthiasis - by the name of the worms: trichinosis, schistosomiasis, filariasis, toxocariasis.
• helminth ophthalmic infections - when parasites affect the eyes and more pronounced pathological changes are caused by the larvae and developmental stages of the worms.

Habitat

Parasitic worms are found from the Arctic to the Equator, but worms characteristic of the tropics will not be diagnosed in residents of northern latitudes.The degree of infection of the population with helminthic infections depends on the economic level of the country and the climate.The most common types of worms are pinworms, roundworms and whipworms.The source of infection becomes the organism - the final host.

Ways of worm infection:

1. The nutritional route is eating unwashed or fly-infested food, insufficient heat treatment of meat, eating raw fish, drinking unboiled water, swallowing water when swimming in reservoirs, using the same knife for raw and cooked food.
2. Fecal-oral transmission: contaminated household items, dirty hands after going to the bathroom, contact with animals.
3. Transmission path.Transmission through insect bites.

Pet infection

When you come into contact with a dog, you can become infected with tapeworm, echinococcus, roundworm and swine tapeworm.Worm eggs can be in dogs' fur and, in addition, these animals have a habit of eating other people's feces while walking.From cats: the same as in dogs, as well as cat worm, from chicken - roundworms, from humans - pinworms, dwarf and porcine tapeworms, hookworm.

How do worms act in the body?

Parasites sensitize the body with their waste products, toxins and enzymes, resulting in:

• allergies and poisoning;
• mechanical damage to mucous membranes with suction cups and hooks;
• Large worms can block the intestinal lumen.
• in addition, worms eat a significant part of the incoming BZHU, which causes anemia, deficiency of vitamins, microelements, hypoxia, malnutrition;
• digestive disorders are observed, children experience a delay in psychophysical development.
• With many helminthiases, chronic microblood loss occurs.
• helminths worsen the course of existing pathologies, suppress the immune system, increase the risk of tuberculosis and cancer, and reduce the effectiveness of vaccines.

Characteristics of the most common worms

What do roundworms look like?When cut, they have a round shape, which is why they got their name.Roundworms have their own characteristics.Firstly, this is their extraordinary resistance: they remain alive in formaldehyde for 5 years.In addition, they are distinguished by a simple development cycle, a straight tube-shaped digestive system and rapid reproduction.

Pinworms cause enterobiasis (anthroponotic disease, dirty hands disease).They resemble small white worms measuring up to 1 cm (males are only 3 mm), the end of the body is slightly pointed.They live in the lower parts of the small intestine and the initial part of the large intestine.They are contact worms.Egg laying occurs in the anus region.The development cycle lasts 2 weeks, they live 1 to 2 months.More common in children.They are attached to the intestinal wall via cephalic vesicles.Female worms descend to the anus at night and lay eggs here.At the same time, they secrete a special type of liquid that causes itching.A child scratches his bottom and self-infection occurs.After laying eggs, the females die.The damage they cause is the release of enzymes that irritate the intestinal walls and contribute to their inflammation.

Roundworms cause ascariasis.They are reddish-white roundworms up to 50 cm long and 6 cm wide.Males have a curved end.Roundworms live in the small intestine, but the larvae actively migrate throughout the body, their life cycle reaches one year.Worm larvae live in the lungs.Its residues cause poisoning and intestinal obstruction.

The parasites are geohelminths, that is, they develop in the soil and from there reach humans.They are distinguished by their enormous fertility, up to 240 thousand eggs per day.The eggs have a very strong three-layer shell and fall easily to the ground.Here, under the influence of oxygen, moisture and a certain temperature, larvae form in them.This process can take anywhere from 2 weeks to several months depending on the temperature.This mature egg with a larva enters the person again orally.The larva emerges in the intestines and is transported throughout the body in the bloodstream.Its preferred habitat is the alveoli of the lungs, as there is access to oxygen and the larva is aerobic.Adults are anaerobes.Having reached 3-4 mm in length, after 4-5 days the larva moves into the bronchi, which causes a cough.When coughed, it is swallowed and returns to the intestine, where it develops to maturity.The life cycle of the parasite reaches one year.

Trichuriasis causes trichuriasis, belongs to nematodes, has a color ranging from grayish to reddish, reaches 2 to 5 cm, has a pointed tip in the shape of hair, which is why it received its name.The parasite adheres to the intestinal wall and feeds on the host's blood and mucous tissues.It lives in the large intestine and appendix, here the larvae reach sexual maturity and lay 3,500 eggs daily.The life cycle of the parasite is 4 to 5 years.By damaging the intestinal wall, they contribute to its damage: causing appendicitis, diarrhea, abdominal pain, anemia.Helminth eggs enter the soil with human feces, where they can persist for up to 2 years.

Toxocara causes toxocariasis.This is a yellowish worm that resembles a roundworm but is 15 to 20 cm long.It is a biohelminth;humans are infected by dogs.They live in the form of eggs.In the human intestine, larvae emerge from them.They migrate throughout the body, damaging internal organs and causing allergies.The severity of the clinic depends on immunity and the number of helminths.Egg laying per day - up to 250 thousand.Life cycle - up to 10 years.

Trichinella spiralis causes trichinosis, considered the most dangerous of helminthiasis, as it often ends in death.The nematode is only 5 mm long.Infestation occurs when undercooked pork is eaten.The trichinella in the intestine is fertilized, the larvae are gestated and hatch inside the female.At one end, the female attaches itself to the intestinal wall and expels up to 2,000 live larvae.This process is called ovoviviparity and takes 3 to 4 days.The larvae are transported through the bloodstream and settle in the striated muscles, mainly in the masticatory, oculomotor, respiratory and shoulder flexor tracts.The disease is serious: 2 weeks after the invasion, pain appears in the abdomen, muscles, head and joints, fever, swelling of the face and intoxication.In the muscles, after one month, the larvae become encapsulated in a spiral shape and can remain in a cyst state for 20 years without losing viability.After 1.5 months, recovery occurs with adequate treatment.

Hookworm and necator are similar to each other, so their helminthiasis is given a common name - hookworm.They measure up to 1.5 cm in length and parasitize the duodenum.Helminth is common but rarely detected.The larvae can penetrate the skin when they come into contact with the soil.The development cycle is very similar to that of roundworms.Hookworm lives in the intestines and feeds only on blood.An individual can absorb 0.35 ml of blood per day.Therefore, a characteristic feature is anemia and dysproteinemia.

Flatworms have a flattened shape.They have no gender differences;they are hermaphrodites.They are attached to the intestines using hooks and suction cups.

The bull tapeworm is a tapeworm that causes teniarinchiasis.It has a small head with 4 suction cups and 6 hooks and a ribbon body with 1000 segments, reaching 20 m in length.The parasite is a biohelminth, infection occurs through beef, where its larvae are located.Each segment contains hundreds of thousands of eggs.Without treatment, the tapeworm parasitizes humans for up to 20 years.It lives in the small intestine, sucking nutrients from the entire surface of the body.Lives up to 10 years.

Pork tapeworm is a tapeworm that causes taeniasis or cysticercosis.It reaches 3-8 m and has a double hooked ring.The life cycle is 20 to 30 years.It can live in any organ and is found in undercooked pork.The cycle is similar to that of bull tapeworm.The segments of this tapeworm can crawl out of the anus, here on the surface of the skin they burst and the eggs come out.The helminth parasitizes the intestine, causing allergies and gastrointestinal problems.

The broad tapeworm causes diphyllobothriasis.The parasite is more than 10 m long, flat and wide.The biohelminth reaches humans through freshwater fish or crustaceans.For decades, worms parasitize the small intestine, clinging to its wall.Within 25 days, the parasites become adults.They feed on blood, causing diarrhea and abdominal pain.

Echinococcus is a biohelminth, a small tapeworm, up to 3-5 mm.On its head there are 2 corollas of hooks and suckers;the parasite has 4-5 segments.The last one is your reproductive system.In the organs it forms cysts measuring up to 10 cm (Finnish), where eggs and larvae are located.Cysts destroy surrounding tissue.They may rupture and then develop toxic shock or multiple new cysts.The final owner is the wolf, the intermediate owner is the man.Infection through food or after contact with domestic animals.In the intestine, larvae (oncospheres) emerge from eggs and are transported throughout the body by the bloodstream.They settle, as a rule, in the parenchyma of the liver and lungs, but they also live in the intestines.Cysts can only be removed surgically.

Cat fluke is a liver fluke, cat fluke or Siberian fluke.Causes opisthorchiasis.It has a lanceolate shape, 1-2 cm long and 2 mm wide, with 2 oral suckers on the head.People become infected through infected freshwater fish that have eaten a snail or crustacean with worm eggs.Humans are the main host.The parasite lives in the lumen of the small intestine and bile ducts.The life cycle is up to 20 years;thousands of individuals parasitize an organism at the same time.The acute phase of the disease is characterized by pain in the upper abdomen, fever, nausea, myalgia, diarrhea and skin rashes.When the process becomes chronic, symptoms of hepatocholecystitis are noted, which do not disappear even after the worms are expelled.

Disease course and symptoms

During the acute phase, symptoms may appear at different times depending on the incubation period, but usually begin after 2 to 3 weeks.The most common symptoms: allergic skin rash, lymphadenopathy, development of local or general edema, arthralgia and myalgia.When migrating to the lungs, coughing, choking episodes, stool disorders (diarrhea), nausea and vomiting may occur.

In the chronic phase, symptoms depend on the organ where the parasites have settled and their number.Key features include:

• frequent itching in the anal area;
• headaches;
• dizziness;
• sleep disorders;
• flatulence;
• rash and itching;
• exhaustion with increased appetite;
• joint and muscle pain;
• yellowing of the skin;
• fatigue.
• prolonged low fever may occur;
• discomfort in the umbilical region or right hypochondrium;
• periodic nausea and vomiting;
• bruxism;
• apathy.

The patient presents with pale, dry skin, loss of hair, eyebrows, eyelashes, brittle nails, tooth decay, bleeding gums and bad breath.

Diagnostic and preventive measures

To make the diagnosis, a scraping is taken from the rectum and perianal region and a stool analysis is also performed.In this case, the worms are clearly visible under the microscope.A blood test is done to check eosinophils and protein balance.The contents of the sputum, stomach and duodenum can be examined.

Any helminths in humans are prevented by constant personal and public hygiene, sufficient heat treatment of meat and fish.Regular veterinary examinations and additional treatment of all pets are required.