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 body of humans and animals.They cause pathologies called helminthiases.According to WHO, every year 50% of the population becomes infected with: pinworms (1.2 billion people), hookworms (900 million) and whipworm (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 worms in humans are divided into 2 large groups: flat and round (nematodes).In turn, flat ones are divided into tapeworms (cestodes) and flukes (trematodes).Cestodes are also divided into tapeworms and tapeworms.

The opinion that worms in humans live only in the intestines is a misconception; they can migrate with the bloodstream throughout the body and settle in a variety of places.All types of parasitic worms feed at the expense of 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 settle in the body of animals, using them as intermediate hosts.In this process, carriers are of great importance: mechanical - these can be insects that carry worms over distances on their legs.Worms do not live in the body of insects.

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

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

Peculiarities of worm reproduction

For the most part, 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 only one owner, they are geohelminths.

Stages of development of worms:

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 occurs in the gastrointestinal tract.It migrates throughout the body, looking for an ideal habitat.Having found it, it continues to develop into 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 suitable for themselves, that is, for example, larvae, for which the host is an ungulate, will survive if they enter the body of a predator, but they will not lay eggs there.

Types of helminthiases

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, teniarinchiasis 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, so 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.
• ophthalmic helminth infections - when parasites affect the eyes, and more pronounced pathological changes are caused by the larvae and developing 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 helminth infections depends on the economic level of the country and climate.The most common types of worms are pinworms, roundworms, and whipworms.The source of infection becomes the organism - the final host.

Ways of infection with worms:

1. The nutritional route is eating unwashed or fly-infested foods, 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 foods.
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

By contact with a dog, you can become infected with tapeworm, echinococcus, roundworm, and pork tapeworm.Worm eggs can be on 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 fluke, from chicken - roundworms, from humans - pinworms, dwarf and pork tapeworms, hookworm.

How do worms act on the body?

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

• allergies and intoxication;
• 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 noted, children have a lag in psychophysical development.
• With many helminthiases, chronic microblood loss occurs.
• helminths worsen the course of existing pathologies, suppress the immune system, they increase the risk of tuberculosis and cancer, and reduce the effectiveness of vaccinations.

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, this is their extraordinary endurance: they remain alive in formaldehyde for 5 years.In addition, they are distinguished by a simple development cycle, a digestive system in the form of a straight tube, and rapid reproduction.

Pinworms cause enterobiasis (anthroponotic disease, 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 initial part of the large intestine.They are contact worms.Egg laying occurs in the anus area.The development cycle lasts for 2 weeks, they live for 1-2 months.More common in children.They are attached to the intestinal wall using head vesicles.Female pinworms descend to the anus in the evenings 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 harm they cause is the release of enzymes that irritate the intestinal walls and contribute to their inflammation.

Roundworms cause ascariasis.These are reddish-white roundworms up to 50 cm long and up to 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 from there they 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 easily fall into the soil.Here, under the influence of oxygen, humidity and a certain temperature, larvae form in them.This process can take from 2 weeks to several months, depending on the temperature.Such a mature egg with a larva again enters the person orally.The larva emerges in the intestines and is carried throughout the body by the bloodstream.Its favorite habitat is the alveoli of the lungs, since 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 coughing up, it is swallowed and goes back to the intestines, where it develops to maturity.The life cycle of the parasite reaches up to a year.

Whipworm causes trichuriasis, belongs to the nematodes, has a color from grayish to reddish, reaches 2-5 cm, has a sharp hair-like head end, which is why it got its name.The parasite clings to the intestinal wall and feeds on the host’s blood and mucosal tissues.It inhabits the large intestine and appendix, here the larvae reach sexual maturity and lay 3.5 thousand eggs daily.The life cycle of the parasite is 4-5 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 an roundworm, but is 15-20 cm long. It is a biohelminth; humans become infected from 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.Laying eggs 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 eating poorly cooked pork.Trichinella in the intestine is fertilized, the larvae are gestated and hatch inside the female.At one end, the female attaches to the intestinal wall and throws out up to 2 thousand live larvae.This process is called ovoviviparity and takes 3-4 days.The larvae are carried 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, fever, 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 cyst-like state for 20 years without losing their viability.After 1.5 months, recovery occurs with proper treatment.

Hookworm and necator are similar to each other, so their helminthiasis is given a common name - hookworm.They are up to 1.5 cm long and parasitize the duodenum.The helminth is common, but rarely detected.The larvae can penetrate the skin upon contact with the soil.The development cycle is very similar to roundworms.Hookworm lives in the intestines and feeds only on blood.One 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.

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

Pork tapeworm is a tapeworm that causes taeniasis or cysticercosis.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 with poorly cooked pork.The cycle is similar to the bullish 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 intestines, causing allergies and gastrointestinal problems.

Broad tapeworm causes diphyllobothriasis.The parasite is more than 10 m long, it is flat and wide.Biohelminth reaches humans through freshwater fish or crustaceans.For tens of years, worms parasitize in the small intestine, clinging to its wall.In 25 days, the parasites grow to 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 his reproductive system.In organs it forms cysts up to 10 cm (Finns), where eggs and larvae are located.Cysts destroy surrounding tissue.They can rupture, then toxic shock or multiple new cysts develop.The final owner is the wolf, the intermediate owner is man.Infection through nutrition or after contact with domestic animals.In the intestine, larvae (oncospheres) emerge from the eggs and are carried throughout the body by the bloodstream.They settle, as a rule, in the parenchyma of the liver and lungs, but also live in the intestines.Cysts can only be removed surgically.

The 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 are 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 in one organism at once.The acute phase of the disease is characterized by pain in the upper abdomen, fever, nausea, myalgia, diarrhea, and rashes.When the process becomes chronic, symptoms of hepatocholecystitis are noted, and they do not go away even after the worms are expelled.

Course of the disease and symptoms

During the acute phase, symptoms may 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, there may be coughing, attacks of suffocation, stool disturbances (diarrhea), nausea and vomiting.

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

• frequent itching in the anal area;
• headaches;
• dizziness;
• sleep disorders;
• flatulence;
• rash and itching;
• exhaustion with increased appetite;
• joint and muscle pain;
• yellowness of the skin;
• fatigue.
• prolonged low-grade fever may occur;
• discomfort in the umbilical region 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 make a diagnosis, a scraping is taken from the rectum and perianal area, and a stool analysis is also performed.In this case, worms are very clearly visible under a microscope.A blood test is taken for eosinophils and protein balance.Sputum, stomach and duodenal contents 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.