The most common types of worms in humans

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

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

The idea that worms in humans live only in the intestines is wrong;they can migrate through the bloodstream throughout the body and settle in various places.All types of parasitic worms feed on their host and use it for their life cycle.

Circulation of worms in nature

To preserve their species, parasites must constantly move into the external environment, leaving their host, and inhabit the body of animals, using them as intermediate hosts.Carriers are of great importance in this process: mechanical - they can be insects that carry worms over a distance on their legs.Worms do not live in the body of insects.

A specific carrier or intermediate host - in which the parasites pass only one of their developmental cycles.During circulation, the way of transmission of worms is important:

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

Peculiarities of worm reproduction

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

Stages of worm development:

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

Types of helminthiasis

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, teniarynchiasis and others.Tissues live in the thickness of different organs and tissues.What organs can be affected by worms?They can accumulate and affect the hepatobiliary system, brain, eyes, lymph nodes, lungs, so the diseases can be called several names:

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

Habitat

Parasitic worms are found from the Arctic to the equator, but those worms that are characteristic of the tropics will not be diagnosed in residents of northern latitudes.The degree of infection of the population with helminths 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 food route is eating unwashed food or food infested with flies, insufficient thermal processing of meat, eating raw fish, drinking unboiled water, swallowing water while swimming in tanks, using the same knife for raw and cooked food.
2. Fecal-oral transmission: contaminated household items, unwashed hands after using the toilet, contact with animals.
3. Transmission path.Transmission through insect bites.

Infection from pets

In contact with a dog, you can become infected with tapeworm, echinococcus, roundworms and pork tapeworm.Worm eggs can be on the fur of dogs, and besides, these animals have a habit of eating other people's feces while walking.From cats: the same as for dogs, as well as cat fluke, from chicken - roundworms, from humans - pinworms, dwarf and pig tapeworms, hookworms.

How do worms affect the body?

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

• allergies and intoxications;
• mechanical damage to the mucous membrane with rubber cups and hooks;
• large worms can block the intestinal lumen.
• in addition, worms eat a significant part of incoming BZHU, which causes anemia, lack of vitamins, microelements, hypoxia, malnutrition;
• digestive disorders are observed, children have delays in psychophysical development.
• In many helminthiases, there is a chronic loss of microblood.
• helminths worsen the course of existing pathologies, suppress the immune system, increase the risk of tuberculosis and cancer and reduce the effectiveness of vaccination.

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.First of all, it is their exceptional durability: they remain alive in formaldehyde for 5 years.In addition, they are characterized by a simple development cycle, a digestive system in the form of a straight tube, and rapid reproduction.

Pinworms cause enterobia (anthroponosis, dirty hands disease).They look like small white worms 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 beginning of the large intestine.They are contact worms.Egg laying takes place in the anus area.The development cycle lasts 2 weeks, they live 1-2 months.More often in children.They are attached to the intestinal wall using vesicles on the head.Female pinworms descend into the anus in the evening and lay eggs here.At the same time, they secrete a special type of liquid that causes itching.The child scratches his bottom and self-infection occurs.After laying the 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 round worms 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 up to a year.Worm larvae live in the lungs.Their waste products cause intoxication and intestinal obstruction.

Parasites are geohelminths, that is, they develop in the soil and reach people from there.They are characterized by enormous fertility, up to 240 thousand eggs per day.The eggs have a very strong three-layered shell and fall easily into the ground.Here, under the influence of oxygen, moisture and a certain temperature, larvae are formed in them.This process can take from 2 weeks to several months, depending on the temperature.Thus, the mature egg with the larva re-enters the person orally.The larva emerges in the intestines and is carried throughout the body through the bloodstream.Its favorite habitat is the lung alveoli, because 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 coughing.When coughed up, it is swallowed and returned to the intestines, where it develops to maturity.The life cycle of the parasite reaches up to one year.

Whipworm causes trichuriasis, belongs to nematodes, has a color from grayish to reddish, reaches 2-5 cm, has a sharp hair-like tip, which is why it got its name.The parasite clings to the intestinal wall and feeds on the host's blood and mucous tissue.It inhabits the large intestine and appendix, here the larvae reach sexual maturity and lay 3.5 thousand eggs per day.The life cycle of the parasite is 4-5 years.By damaging the intestinal wall, they contribute to its damage: they cause appendicitis, diarrhea, abdominal pain, and anemia.Helminth eggs enter the soil with human feces, where they can survive for up to 2 years.

Toxokara causes toxocarosis.This is a yellowish worm that resembles a roundworm, but is 15-20 cm long.It is a biohelminth;people get infected from dogs.They live in the form of eggs.Larvae emerge from them in the human intestine.They migrate throughout the body, damage internal organs and cause 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, which is 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.Trichinella in the intestines are fertilized, the larvae are pregnant and hatch inside the female.At one end, the female attaches to the intestinal wall and ejects up to 2,000 live larvae.This process is called ovoviviparity and lasts 3-4 days.The larvae are transmitted through the bloodstream and settle in the striated muscles, especially in the masticatory, oculomotor, respiratory tracts and shoulder flexors.The disease is severe: 2 weeks after the invasion, pain in the abdomen, muscles, head and joints, elevated temperature, swelling of the face and intoxication appear.In the muscles, after a month, the larvae are encapsulated in the form of a spiral and can remain in a cystic state for 20 years without losing vitality.After 1.5 months, recovery occurs with proper treatment.

Hookworm and nekator are similar to each other, so their helminthosis is given a common name - hookworm.They are up to 1.5 cm long and parasitize the duodenum.Helminths are common but rarely detected.Larvae can penetrate the skin after contact with soil.The development cycle is very similar to roundworms.The hookworm lives in the intestines and feeds only on blood.One person can absorb 0.35 ml of blood per day.Therefore, the characteristic feature is anemia and dysproteinemia.

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

The bull tapeworm is the tapeworm that causes taeniarhynchiasis.It has a small head with 4 teats and 6 hooks and a tape body of 1000 segments, which reaches 20 m in length.The parasite is a biohelminth, the infection occurs through beef, where its larvae are located.Each segment contains hundreds of thousands of eggs.Without treatment, tapeworms parasitize people for up to 20 years.It lives in the small intestine and sucks nutrients all over the body.Lives up to 10 years.

Pig tapeworm is a tapeworm that causes taeniasis or cysticercosis.it reaches 3-8 m and has a double rim of hooks.The life cycle is from 20 to 30 years.It can live in any organ and is found in poorly cooked pork.The cycle is similar to the bull tapeworm.The segments of this tapeworm can crawl out of the anus, here on the surface of the skin they crack and the eggs come out.The helminth parasitizes the intestines, causing allergies and gastrointestinal problems.

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

Echinococcus is a biohelminth, a small tapeworm, up to 3-5 mm.On the head there are 2 corollas of hooks and teats;the parasite has 4-5 segments.The last is his reproductive system.In the organs, it forms cysts up to 10 cm (Finci), where eggs and larvae are located.Cysts destroy the surrounding tissue.They may rupture and then develop toxic shock or multiple new cysts.The ultimate owner is a wolf, and the intermediate owner is a man.Infection through food or after contact with domestic animals.In the intestines, the larvae (oncospheres) emerge from the eggs and are spread throughout the body through 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 liver fluke, cat fluke or Siberian fluke.It causes opisthorchiasis.It is spear-shaped, 1-2 cm long and 2 mm wide, with 2 nipples on the head.Humans become infected through infected freshwater fish that have eaten a snail or crustacean with worm eggs.People 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 one organism at a time.The acute phase of the disease is characterized by upper abdominal pain, fever, nausea, myalgia, diarrhea and rash.When the process becomes chronic, symptoms of hepatocholecystitis appear, which do not disappear even after the worm is expelled.

Disease course and symptoms

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

In the chronic phase, the symptoms depend on the organ in which the parasites 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 temperature may occur;
• discomfort in the navel area or in the right hypochondrium;
• periodic nausea and vomiting;
• bruxism;
• apathy.

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

Diagnostic measures and prevention

To establish a diagnosis, a scraping is taken from the rectum and perianal area, and a stool analysis is also done.In this case, the worms are very clearly visible under the microscope.A blood test is taken for eosinophils and protein balance.Sputum, contents of the 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 further treatment of all pets are necessary.