The most common types of worms in humans

Various types of worms are found everywhere, 80% of those affected are children.Helminths or worms (from the Greek word parasite worm) are lower order worms that live in the bodies of humans and animals.They cause pathologies called helminthiasis.According to the WHO, 50% of the population is infected with pinworms (1.2 billion people), hookworms (900 million) and whipworms (up to 700 million people) 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 human worms are divided into 2 large groups: flat and round (nematodes).Flatworms, on the other hand, are divided into tapeworms (cestodes) and flukes (trematodes).Cestodes are also divided into tapeworms and tapeworms.

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

The circulation of worms in nature

To preserve 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.Carriers are of great importance in this process: mechanical - these can be insects that carry worms on their legs.Worms do not live in the bodies of insects.

A specific carrier or intermediate host - in this the parasites go through only one development cycle.The mode of transmission of worms during circulation matters:

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

Peculiarities of worm reproduction

Lower worms are mostly 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.

Developmental stages of worms:

1. Egg stages - the female lays immature eggs, which mature in the external environment and are then returned to humans orally.
2. The second stage is when the larva hatches from the egg.This process takes place in the gastrointestinal tract.It travels throughout 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 them, such as larvae, whose host is an ungulate, they survive if they enter the body of a predator, but do not lay eggs there.

Types of helminthiasis

The types of helminths found 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 in the intestines: ascariasis, trichuriasis, strongyloidiasis, teniarynchiasis and others.Tissues live in the thickness of different organs and tissues.What organs can worms affect?They can colonize and affect the hepatobiliary system, the brain, the eyes, the lymph nodes, the lungs, so the diseases can have several names:

• in case of liver damage - echinococcosis;
• brain damage - cysticercosis;
• lymph nodes - filariasis;
• lung helminthiasis - paragonimiasis;
• tissue helminthiasis - by the name of the worms: trichinosis, schistosomiasis, filariasis, toxocariasis.
• ophthalmic intestinal worm infections - when the parasites affect the eye and cause more pronounced pathological changes in the larvae and developing stages of the worms.

Habitat

Parasitic worms are found from the Arctic to the Equator, but tropical worms are not diagnosed in 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 worms are pinworms, roundworms and whipworms.The source of infection will be the body - the final host.

Ways of infection with worms:

1. The nutritional route is eating unwashed or fly-infested food, improper 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. Fecal-oral spread: contaminated household items, unwashed hands after using the toilet, contact with animals.
3. Transmission path.It is spread by insect bites.

Infection of domestic animals

During contact with a dog, you can become infected with tapeworms, echinococcus, roundworms and pig tapeworms.Worm eggs can also be found on the fur of dogs, and these animals also have a habit of eating other people's excrement while walking.From cats: the same as for dogs, as well as cat distemper, from chickens - roundworms, from humans - roundworms, dwarf and pig tapeworms, hookworms.

How do worms affect the body?

Parasites sensitize the body with their waste materials, toxins and enzymes, which:

• allergy and poisoning;
• mechanical damage to mucous membranes with suction cups and hooks;
• large worms can block the intestinal lumen.
• in addition, the worms eat a significant part of the incoming BZHU, which causes anemia, vitamin and microelement deficiency, hypoxia, and malnutrition;
• digestive disorders can be observed, children lag behind in their psychophysical development.
• Chronic microblood loss occurs in many helminthiasis.
• 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.Cylindrical worms have their own characteristics.First of all, it is their extraordinary endurance: they can survive 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 part of the small intestine and the beginning of the large intestine.These are contact worms.Egg laying takes place in the area of the anus.The development cycle lasts 2 weeks, they live for 1-2 months.More common in children.It is attached to the intestinal wall with the help of head vesicles.Female pinworms descend into the anus in the evening and lay eggs there.At the same time, they secrete a special liquid that causes itching.A child scratches their bottom and self-infection occurs.After laying eggs, the females die.The damage they cause involves the release of enzymes that irritate the intestinal walls and contribute to their inflammation.

Roundworms cause ascariasis.These are reddish-white cylindrical 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 one year.The worm larvae live in the lungs.Their impurities cause poisoning and intestinal obstruction.

The parasites are geohelminths, that is, they develop in the soil and reach humans from there.They are characterized by their enormous fertility, up to 240,000 eggs per day.The eggs have a very strong three-layered shell and fall easily into the soil.Here, under the influence of oxygen, humidity 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 its larva enters the human again through the mouth.The larva appears in the intestines and travels throughout the body through the bloodstream.Its favorite habitat is the alveoli of the lungs, as it has access to oxygen and the larva is aerobic.Adults are anaerobic.The larva, which is 3-4 mm long, moves into the bronchi after 4-5 days, causing a cough.It is swallowed when you cough and goes back to the intestines, where it develops to maturity.The life cycle of the parasite reaches one year.

The whipworm causes trichuriasis, it belongs to nematodes, its color ranges from gray to reddish, 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 mucosal tissues of the host.It lives in the colon and cecum, where the larvae reach sexual maturity and lay 3,500 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 excrement, where they can remain for up to 2 years.

Toxocara causes toxocariasis.It is a yellowish worm that looks like a roundworm but is 15-20 cm long.It is a biohelminth;humans 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.Daily egg laying - 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.The infection occurs when eating poorly cooked pork.The trichinella in the intestine is fertilized, the larvae are pregnant and hatch inside the female.At one end, the female clings to the intestinal wall and throws out up to 2,000 live larvae.This process is called ovoviviparity and lasts 3-4 days.The larvae travel through the bloodstream and colonize the striated muscles, especially the muscles of mastication, eye movements, airways, and shoulder flexors.The disease is serious: 2 weeks after the invasion, abdominal, muscle, head and joint pain, fever, swelling of the face and poisoning appear.After a month in the muscles, 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 takes place with appropriate 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 in the duodenum.Helminths are common but rarely detected.The larvae can penetrate the skin in contact with the soil.The development 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.Anemia and dysproteinemia are therefore typical.

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

The bull tapeworm is a tapeworm that causes taeniahrynchiasis.It has a small head with 4 grippers and 6 hooks and a ribbon body of 1000 segments that reaches 20 meters.The parasite is a biohelminth, the infection occurs through beef, where its larvae are found.Each segment contains hundreds of thousands of eggs.Without treatment, tapeworms can parasitize humans for up to 20 years.It lives in the small intestine and absorbs nutrients over the entire surface of the body.It lives up to 10 years.

The pig tapeworm is a tapeworm that causes taeniasis or cysticercosis.it reaches 3-8 m and has a double hook rim.The life cycle is 20-30 years.It can live in any organ and can be found in poorly cooked pork.The cycle is similar to the bullish tapeworm.The segments of this tapeworm can crawl out of the anus, where the skin breaks and the eggs come out.The helminth is a parasite in 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.Worms live in the small intestine for tens of years, 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 are 2 hook-and-eye corollas;the parasite has 4-5 segments.The last is your reproductive system.It forms cysts of up to 10 cm in the organs (fins), where the eggs and larvae are located.Cysts destroy the surrounding tissues.They may rupture and then develop toxic shock or several new cysts.The final owner is the wolf, the intermediate owner is the human.Infection through food or after contact with domestic animals.Larvae (oncospheres) emerge from the eggs in the intestine and travel throughout the body through the bloodstream.They usually settle in the parenchyma of the liver and lungs, but they also live in the intestines.Cysts can only be removed surgically.

Feline fluke is liver fluke, cat fluke or Siberian fluke.It causes opisthorchiasis.Spear-shaped, 1-2 cm long and 2 mm wide, 2 mouth suckers on the head.Humans are infected by infected freshwater fish that have eaten a snail or crustacean with worm eggs.Man is the main employer.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 the same time.The acute phase of the disease is characterized by upper abdominal pain, fever, nausea, muscle pain, diarrhea and rashes.When the process becomes chronic, the symptoms of hepatocholecystitis are noticeable and do not go away even after the worms are expelled.

Course and symptoms of the disease

In 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 are: allergic rashes, lymphadenopathy, development of local or general edema, joint pain and muscle pain.When it migrates to the lungs, coughing, suffocation, stool disorder (diarrhea), nausea and vomiting may occur.

In the chronic phase, the symptoms depend on the organ and number of parasites.The main features are:

• frequent itching in the anal area;
• headache;
• dizziness;
• sleep disorders;
• bloating;
• 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 navel or right hypochondrium;
• periodic nausea and vomiting;
• bruxism;
• apathy.

The patient's skin is pale, dry, hair loss, eyebrows, eyelashes, brittle nails, tooth decay, bleeding gums and bad breath are experienced.

Diagnostic measures and prevention

To establish the diagnosis, a scraping is made from the rectum and perianal area, and a stool analysis is also performed.In this case, the worms are very clearly visible under a microscope.Blood tests are taken to determine eosinophils and protein balance.Sputum, stomach and duodenal contents can be examined.

Helminths occurring in humans are prevented by constant personal and public hygiene and proper heat treatment of meat and fish.All pets require regular veterinary examination and further treatment.