The most common types of worms in humans

Different 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 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 opinion that worms in humans only live in the intestines is a misconception;they can migrate with the blood circulation throughout the body and settle in various places.All types of parasitic worms feed at the expense of their host and use it throughout their life cycle.

Movement of worms in nature

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

A specific carrier or intermediate host - parasites undergo only one of their development cycles there.During circulation, the mode of transmission of worms is important:

• 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 sex differences - nematodes.If helminths change host 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, 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, searching for an ideal habitat.After finding 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 them, that is, for example, larvae, the host of which is an ungulate, will survive if they enter the body of a predator, but they 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, taeniarinchiasis 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, lungs, so diseases can have several names:

• for liver damage - echinococcosis;
• brain damage - cysticercosis;
• lymph nodes - filariasis;
• pulmonary helminthiasis - paragonimiasis;
• tissue helminthiasis - named after 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 stages of development of worms.

Habitat

Parasitic worms are found from the Arctic to the equator, but worms characteristic of the tropics will not be diagnosed in inhabitants 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 infection with worms:

1. The nutritional way involves eating unwashed or fly-infested food, insufficient heat treatment of meat, eating raw fish, drinking unboiled water, swallowing water while swimming in reservoirs, using the same knife for raw and cooked food.
2. Faecal-oral transmission: contaminated household items, unwashed hands after using the toilet, contact with animals.
3. Transmission path.Transmission by insect bites.

Infection from pets

Through contact with a dog, you can become infected with tapeworm, echinococcus, roundworm and pork tapeworm.Worm eggs can be found on the fur of dogs and, in addition, these animals have the habit of eating other people's feces while walking.In cats: the same as in dogs, as well as cat fluke, in chicken - roundworms, in humans - pinworms, dwarf and porcine tapeworms, hookworm.

How do worms affect the body?

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

• allergies and poisonings;
• 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, deficiency of vitamins, microelements, hypoxia, malnutrition;
• digestive disorders are noted, children have a delay in psychophysical development.
• With many helminthiases, chronic loss of microblood 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?Once cut, they have a round shape, hence their name.Roundworms have their own characteristics.First of all, it is their extraordinary endurance: 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 look like 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.These are contact worms.Egg laying takes place 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 using head vesicles.Female pinworms descend to the anus in the evening and lay their eggs there.At the same time, they secrete a special type of fluid that causes itching.A child scratches his butt and self-infection occurs.After laying eggs, 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 measuring 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 and their life cycle can be up to one year.Worm larvae live in the lungs.Their waste causes poisoning and intestinal obstruction.

The parasites are geohelminths, meaning they develop in the soil and from there reach humans.They are distinguished 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, humidity and a certain temperature, larvae are formed.This process can take anywhere 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 preferred habitat is the alveoli of the lungs, because they have access to oxygen and the larva is aerobic.Adults are anaerobic.Having reached 3 to 4 mm in length, the larva penetrates the bronchi after 4 to 5 days, which causes coughing.When coughed, it is swallowed and returns to the intestines, where it grows to maturity.The life cycle of the parasite can be up to one year.

The whipworm causes trichuriasis, belongs to nematodes, has a color from grayish to reddish, reaches 2-5 cm, has a pointed hair-like head, hence its name.The parasite attaches itself to the intestinal wall and feeds on the blood and mucosal tissues of the host.It inhabits 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 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.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 250,000. Life cycle - up to 10 years.

Trichinella spiralis causes trichinosis, which is considered the most dangerous of helminthiasis, as it often leads to death.The nematode is only 5 mm long.Infestation occurs by eating undercooked pork.Trichinella in the intestine is fertilized, the larvae are pregnant and hatch inside the female.At one end, the female attaches itself to the intestinal wall and releases up to 2,000 live larvae.This process is called ovoviviparity and takes 3 to 4 days.The larvae are transported in the blood and settle in the striated muscles, particularly in the masticatory, oculomotor, respiratory tracts and shoulder flexors.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 a month, the larvae are encapsulated in the form of a spiral and can remain in the cyst state for 20 years without losing their viability.After 1.5 months, healing occurs with appropriate treatment.

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

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

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

Pork tapeworm is a tapeworm that causes taeniasis or cysticercosis.reaches 3 to 8 m and has a double hook edge.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 the bull tapeworm.The segments of this tapeworm can come out of the anus, here on the surface of the skin they burst and the eggs come out.Helminths parasitize the intestines, causing allergies and gastrointestinal problems.

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

Echinococcus is a biohelminth, a small tapeworm measuring up to 3 to 5 mm.On its head are 2 corollas of hooks and suckers;the parasite has 4 to 5 segments.The last is its reproductive system.In the organs it forms cysts up to 10 cm (Finnish), where eggs and larvae are located.Cysts destroy surrounding tissue.They may rupture, then experience toxic shock or several new cysts develop.The final owner is the wolf, the intermediate owner is man.Infection through food or after contact with domestic animals.In the intestine, larvae (oncospheres) emerge from eggs and are carried throughout the body by 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.

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

Evolution 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 to 3 weeks.The most common symptoms: allergic skin rash, lymphadenopathy, development of local or general edema, arthralgia and myalgia.During migration to the lungs, there may be coughing, attacks of choking, stool disturbances (diarrhea), nausea and vomiting.

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

• frequent itching in the anal area;
• headaches;
• dizziness;
• sleep disturbances;
• flatulence;
• rash and itching;
• exhaustion with increased appetite;
• joint and muscle pain;
• yellowing of the skin;
• fatigue.
• a mild, prolonged fever may occur;
• discomfort in the umbilical region or 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 carried out in the rectum and perianal region, as well as a stool analysis.In this case, the worms are very clearly visible under a microscope.A blood test is done for eosinophils and protein balance.Sputum, stomach and duodenal contents may be examined.

Helminths in humans are prevented by constant personal and public hygiene and sufficient heat treatment of meat and fish.Regular veterinary examinations and further treatment of all animals are necessary.