The most common types of worms in humans

Various types of worms are found everywhere, with children making up 80% of those affected.Helminths or worms (from the Greek parasitic worm) are inferior 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 by: pinworms (1.2 billion people), hookworm (900 million) and whipworm (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 (filamentous).In turn, flatworms are divided into tapeworms (cestoides) and crustaceans (trematodes).Cestodes are also distinguished into cestoid worms and tapeworms.

The opinion that worms in humans live only in the intestines is a misconception.They can migrate with the blood circulation throughout the body and settle in different places.All species of parasitic worms feed at the expense of their host and use it for their life cycle.

Movement of worms in nature

To maintain their species, parasites must constantly move to the external environment, leaving their host and settling in the body of animals, using them as intermediate hosts.In this process, vectors are of great importance: mechanics - these can be insects that carry worms over distances on their legs.Worms do not live in the body of insects.

A specific vector or intermediate host - in it the parasites undergo only one of their growth cycles.In circulation, the method of transmission of the worms matters:

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

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 growth cycle (sometimes up to 4), they are called biohelminths.If they stay 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 through the mouth.
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.After finding it, he 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 that are 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 will not lay eggs there.

Types of helminths

The types of helminths in humans are divided according to their environment: lumen and tissue.In the first case, parasites live in the lumen of hollow organs, most often in the intestines: ascariasis, trichuria, roundworm, teniargiasis 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 many names:

• for liver damage - echinococcus.
• brain damage - cysticercosis.
• lymph nodes - filariasis;
• pulmonary helminthiasis - paragonimiasis;
• tissue helminthiasis - under the name of worms: trichinosis, schistosomiasis, filariasis, toxocariasis.
• ocular helminthic infections - when parasites affect the eyes and the most 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 these worms characteristic of the tropics will not be diagnosed in the inhabitants 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 food route is eating unwashed or fly-infested food, insufficient heat treatment of meat, eating raw fish, drinking unboiled water, swallowing water when 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.

Contamination from pets

In contact with a dog, you can become infected with tapeworm, echinococcus, roundworm and swine tapeworm.Worm eggs can be found in the fur of dogs, 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 the kitten, from the chicken - roundworms, from humans - pins, dwarf and pig vacuum, hookworm.

How do worms act on the body?

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

• allergies and poisoning.
• mechanical damage to the 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, vitamin deficiency, microelements, hypoxia, malnutrition.
• digestive disorders occur, children have a delay in psychosomatic development.
• With many helminthiasis, 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 vaccinations.

Characteristics of the most common worms

What do roundworms look like?When cut, they are round in shape, hence their name.Roundworms have their own characteristics.First of all, this is their exceptional durability: they remain alive in formaldehyde for 5 years.In addition, they are distinguished by a simple growth cycle, a digestive system in the form of a straight tube and rapid reproduction.

Worms cause enterobiasis (anthropogenic 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 beginning of the large intestine.They are contact worms.Spawning takes place in the anus area.The growth cycle lasts 2 weeks, they live 1-2 months.More common in children.They attach to the intestinal wall using head vesicles.Female pinworms descend into 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 spawning, 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 red-white roundworms up to 50 cm long and 6 cm wide.Males have a curved tip.Roundworms live in the small intestine, but the larvae actively migrate throughout the body, their life cycle reaches up to a year.The larvae of the worms live in the lungs.Their waste causes intoxication and intestinal obstruction.

The parasites are geohelminths, i.e. they grow in the soil and from there they reach humans.They stand out for their enormous fertility, up to 240 thousand eggs per day.The eggs have a very strong three-layered shell and fall easily to the soil.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.Such a mature egg with a larva re-enters the person through the mouth.The larva emerges in the intestines and is carried throughout the body through the bloodstream.Its favorite habitat is the alveoli of the lungs, since there is access to oxygen and the larva is aerobic.Adults are anaerobic.Having reached 3-4 mm in length, after 4-5 days the larva moves to the bronchi, which causes coughing.During coughing, it is swallowed and returned to the intestines, where it grows to maturity.The life cycle of the parasite reaches up to one year.

The flagellate causes trichuriasis, it belongs to the nematodes, it is grayish to reddish in color, it reaches 2-5 cm, it has a sharp hair-like head end, hence its name.The parasite attaches to the intestinal wall and feeds on the blood and mucous tissues of the host.It lives in 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 destroying 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.

Toxocariasis causes toxocariasis.This is a yellowish worm that looks like a roundworm, but is 15-20 cm long.It is a biohelminth.humans are infected by dogs.They live in the form of eggs.In the human intestine, the 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 the helminthiasis, as it often results in death.The nematode is only 5 mm long.The infection occurs when undercooked pork is eaten.The trichinella in the intestine is fertilized, the larvae become pregnant and hatch inside the female.At one end, the female attaches to the intestinal wall and ejects up to 2 thousand live larvae.This process is called spawning and lasts 3-4 days.Larvae are carried through the bloodstream and settle in striated muscles, particularly 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 appropriate treatment.

Hookworm and necator are similar to each other, so their helminthiasis has a common name - hookworm.They are up to 1.5 cm long and parasitize the duodenum.Helminth is common, but rarely detected.Larvae can penetrate the skin on contact with soil.The growth cycle is very similar to roundworms.The hookworm lives in the intestines and feeds only on blood.A person 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 hermaphrodite.They are attached to the intestines using hooks and suction cups.

Bull tape is a tape that causes taenaryngitis.It has a small head with 4 hooks and 6 hooks and a ribbon of 1000 parts, reaching 20 meters in length.The parasite is a biohelminth, infection occurs through beef, where its larvae are.Each section contains hundreds of thousands of eggs.Without treatment, tapeworms parasitize humans for up to 20 years.It lives in the small intestine, absorbing nutrients throughout the body.It lives up to 10 years.

Porcine tapeworm is a tapeworm that causes tapeworm 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 undercooked pork.The circle is similar to the bullish tape.Parts of this tape can be pulled 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.

Broadband causes diphyllobothriasis.The parasite is more than 10 meters long, flat and wide.Biohelminth reaches humans through freshwater fish or crustaceans.For tens of years, the worms parasitize 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 his head are 2 wreaths of hooks and hooks.the parasite has 4-5 segments.The last is its reproductive system.On the organs it forms cysts up to 10 cm (Finns), where the eggs and larvae are located.Cysts destroy the surrounding tissue.They may rupture, then develop toxic shock or multiple new cysts.The ultimate owner is the wolf, the intermediate owner is man.Infection through food or after contact with domestic animals.In the intestine, the 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 they also live in the intestines.Cysts can only be removed surgically.

Cat fluke is a liver fluke, cat fluke or Siberian fluke.It causes retroorchiosis.It has a lance-shaped shape, 1-2 cm long and 2 mm wide, with 2 oral scutes on the head.Humans become infected through contaminated freshwater fish that have eaten a snail or crustacean with worm eggs.Humans are the primary 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 upper abdominal pain, fever, nausea, myalgia, diarrhea and rashes.When the process becomes chronic, symptoms of hepatocholecystitis are noted and do not go away even after the worms are expelled.

Disease course and symptoms

During the acute phase, symptoms can appear at different times, depending on the incubation period, but most often they start 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, suffocation attacks, stool disturbances (diarrhoea), nausea and vomiting.

In the chronic phase, the symptoms depend on the organ in which the parasites have settled and their number.Main features include:

• frequent itching in the anus area.
• headaches;
• dizziness;
• sleep disorders;
• inflation;
• rash and itching;
• exhaustion with increased appetite.
• joint and muscle pain;
• yellowing 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 the diagnosis, a scraping is taken from the rectal 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 done for eosinophils and protein balance.The contents of the sputum, stomach and duodenum can be examined.

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