The most common types of worms in humans

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

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 two large groups: flat and round (nematodes).Flatworms, in turn, are divided into tapeworms (cestodes) and flukes (trematodes).Cestodes are also divided into tapeworms and tapeworms.

The opinion that worms only live in the intestines of humans is a misconception;They can travel through the body in the bloodstream and settle in a wide variety of places.All types of parasitic worms feed at the expense of their host and use it for their life cycle.

Spread of worms in nature

To maintain their species, parasites must constantly penetrate the external environment, leave their host, settle in the bodies of animals and use them as intermediate hosts.Carriers are of great importance: mechanical - these can be insects that transport worms on their legs over long distances.Worms do not live in the bodies of insects.

A specific carrier or intermediate host - in it the parasites only go through one of their development cycles.The circulation depends on the type of transmission of the worms:

• Contact - penetration through intact skin and mucous membranes (hookworm);
• nutritionally.

Peculiarities of worm reproduction

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

Stages of development of worms:

1. Egg stage - the female lays immature eggs, which mature in the external environment and then return to humans orally.
2. In the second stage, a larva hatches from the egg.This process takes place in the gastrointestinal tract.It travels through the body looking for an ideal habitat.After finding it, it continues to develop into an adult.
3. The third stage is the adult laying eggs again.It should be noted that worms do not develop in all organisms, but only in those that are suitable for them, i.e.h.For example, larvae whose host is an ungulate survives when they enter the body of a predator, but do not lay eggs there.

Types of helminthiasis

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

• with liver damage - echinococcosis;
• brain damage - cysticercosis;
• lymph nodes - filariasis;
• pulmonary helminthiasis – paragonimiasis;
• Tissue helminthiasis - with the name of the worms: trichinosis, schistosomiasis, filariasis, toxocariasis.
• Eyeworm infections – when parasites attack 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 the worms typical of the tropics are not 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 the climate.The most common types of worms are pinworms, roundworms and whipworms.The organism – the final host – becomes the source of infection.

Ways of infection with worms:

1. The dietary route consists of eating unwashed or fly-infested foods, inadequately heating meat, eating raw fish, drinking uncooked water, swallowing water while swimming in reservoirs, and 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 route.Transmission through insect bites.

Infection from pets

Through contact with a dog, you can become infected with tapeworms, echinococci, roundworms and pork tapeworms.Worm eggs can be found on the fur of dogs, and these animals also have a habit of eating other people's feces while walking.From cats: the same as in dogs, as well as cat leeches, from chickens – roundworms, from people – pinworms, dwarf and pork tapeworms, hookworms.

How do worms affect the body?

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

• allergies and poisoning;
• mechanical damage to mucous membranes caused by suction cups and hooks;
• Large worms can block the intestinal lumen.
• In addition, worms eat a significant part of the incoming BZHU, which leads to anemia, deficiency of vitamins, microelements, hypoxia and malnutrition.
• Digestive disorders are noted, children have a delay in psychophysical development.
• Many helminthiases result in chronic microblood loss.
• Helminths worsen the course of existing diseases, 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?On average they have a round shape, which is why they get their name.Roundworms have their own characteristics.Above all, this is their extraordinary endurance: they stay 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 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 part of the small intestine and the first part of the large intestine.These are contact worms.Eggs are laid in the anus area.The development cycle lasts 2 weeks, they live 1-2 months.More common in children.They are attached to the intestinal wall via head vesicles.Female pinworms descend to the anus in the evening and lay eggs here.At the same time, they secrete a special fluid that causes itching.A child scratches his butt 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.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 is up to a year.Worm larvae live in the lungs.Their waste products cause poisoning and intestinal obstruction.

Parasites are geohelminths, which means they develop in the soil and from there reach humans.They are characterized by their enormous fertility, up to 240,000 eggs per day.The eggs have a very strong three-layer shell and fall easily into the soil.Here, under the influence of oxygen, moisture and a certain temperature, larvae are formed in them.This process can take anywhere from 2 weeks to several months depending on the temperature.Such a mature egg with a larva again penetrates the human orally.The larva hatches in the intestine and is transported throughout the body via the bloodstream.Its preferred habitat is the alveoli because there is oxygen there and the larva lives aerobically.Adults are anaerobes.After the larva reaches a length of 3 to 4 mm, it migrates to the bronchi after 4 to 5 days, causing coughing.When coughed up, it is swallowed and returns to the intestines, where it matures.The life cycle of the parasite is up to a year.

The whipworm causes trichuriasis, belongs to the nematodes, has a grayish to reddish color, reaches a size of 2-5 cm and has a sharp, hair-like head end, which is why it got its name.The parasite adheres to the intestinal wall and feeds on the blood and mucosal tissue of the host.It colonizes the large intestine and the 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.Worm eggs enter the soil with human feces, where they can survive for up to 2 years.

Toxocara causes toxocariasis.This is a yellowish worm that resembles a roundworm but is 15-20 cm long.It is a biohelminth;People are infected by dogs.They live in the form of eggs.They hatch into larvae in the human intestine.They travel through the body, damaging internal organs and triggering allergies.The severity of the clinic depends on immunity and the number of helminths.Lay eggs per day - up to 250,000.Life cycle - up to 10 years.

Trichinella spiralis causes trichinosis, which is considered the most dangerous helminthiasis and is often fatal.The nematode is only 5 mm long.The infestation occurs when eating poorly cooked pork.Trichinella are fertilized in the intestine, the larvae are impregnated and hatch inside the female.At one end, the female attaches herself to the intestinal wall and ejects up to two thousand live larvae.This process is called ovoviviparity and takes 3-4 days.The larvae are transported via the bloodstream and settle in the striated muscles, especially in the chewing muscles, the eye muscles, the respiratory tract and the shoulder flexors.The disease is serious: 2 weeks after the invasion, pain in the abdomen, muscles, head and joints, fever, facial swelling and intoxication appear.In the muscles, the larvae are spirally encapsulated after a month and can remain in a cyst-like state for 20 years without losing their viability.Recovery occurs after 1.5 months with proper treatment.

Hookworm and necator are similar to each other, so their helminthiasis has a common name - hookworm.They grow up to 1.5 cm long and parasitize the duodenum.The helminth is common but rarely discovered.When they come into contact with the ground, the larvae can penetrate the skin.The development cycle is very similar to that of roundworms.Hookworms live in the intestines and feed exclusively on blood.A person can absorb 0.35 ml of blood per day.A characteristic feature is therefore anemia and dysproteinemia.

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

Bull tapeworm is a tapeworm that causes taeniahrynchiasis.It has a small head with 4 suction cups and 6 hooks and a band body made of 1000 segments that reaches a length of 20 m.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 and absorbs nutrients across the entire surface of the body.Lives up to 10 years.

Pork tapeworm is a tapeworm that causes taeniasis or cysticercosis.Reaches 3-8m in length and features a double hooked edge.The life cycle is 20 to 30 years.It can live in any organ and is found in poorly cooked pork.The cycle is similar to that of 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 and causes allergies and gastrointestinal problems.

The broad tapeworm causes diphyllobothriasis.The parasite is more than 10 m long, flat and wide.Biohelminths reach humans via freshwater fish or crustaceans.For decades, worms have been parasitizing the small intestine and attaching themselves to its wall.The parasites develop into adults within 25 days.They feed on blood and cause diarrhea and abdominal pain.

Echinococcus is a biohelminth, a small tapeworm measuring up to 3–5 mm.On its head are two petals made of hooks and suckers;The parasite has 4-5 segments.The last is its reproductive system.In organs, it forms cysts (fins) up to 10 cm in size, in which eggs and larvae are located.Cysts destroy surrounding tissue.They can rupture, leading to toxic shock or the formation of multiple new cysts.The final owner is the wolf, the intermediate owner is the human.Infection through diet or after contact with pets.Larvae (oncospheres) hatch from the eggs in the intestine and are transported throughout the body via the bloodstream.They usually settle 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.Humans are infected by infected freshwater fish that have eaten a snail or crustacean containing worm eggs.Humans are the main hosts.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 an organism at the same time.The acute phase of the disease is characterized by epigastric pain, fever, nausea, myalgia, diarrhea, and skin rashes.If the process becomes chronic, symptoms of hepatocholecystitis are noted, which do not disappear even after the worms are expelled.

Course of the disease and symptoms

During the acute phase, symptoms can appear at different times depending on the incubation period, but usually 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, suffocation, stool disturbances (diarrhea), nausea and vomiting may occur.

In the chronic phase, the symptoms depend on which organ the parasites have settled in and how many they have.Key features include:

• frequent itching in the anal area;
• Headache;
• Dizziness;
• sleep disorders;
• Flatulence;
• rash and itching;
• exhaustion with increased appetite;
• joint and muscle pain;
• yellowing of the skin;
• Fatigue.
• persistent low-grade fever may occur;
• discomfort in the umbilical region or in the right hypochondrium;
• periodic nausea and vomiting;
• bruxism;
• Apathy.

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

Diagnostic measures and prevention

To make the diagnosis, a swab from the rectum and perianal area as well as a stool analysis is carried out.In this case, worms are very clearly visible under the microscope.A blood test for eosinophils and protein balance is carried out.Sputum, stomach and duodenal contents can be examined.

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