Types of worms in humans and methods of infection with them.

Worms are representatives of lower worms that live in the human body. A disease associated with human infection with various types of worms is called helminthiasis. This disease is not uncommon and occurs among certain segments of the population. Children are susceptible to pinworm infection, hunters (trichinella), fishermen and lovers of Japanese cuisine (raw fish in the form of sushi) suffer from diphyllobothriasis.

Many diseases, paradoxically, can occur in the human body due to helminthiasis. Today, the theory on the relationship between cancer and parasitic infections is one of the most relevant. In the presence of helminthiasis, symptoms do not always appear and, if patients with this disease still experience unpleasant and uncomfortable sensations, they are perceived as signs of other diseases. The patient has been treated for years for pancreatitis, gastritis or colitis, without suspecting that the cause of his illness is helminthiasis.

How infection occurs?

Worms bring a lot of problems to humans.

Helminth infection occurs as follows:

  • Through dirty hands
  • Upon contact with the ground
  • After insect bites
  • For dirty hands
  • By eating raw meat and fish.
  • After eating unwashed fruits and vegetables
  • After contact with an animal.
  • After contact with infected people.

Mature parasite eggs can be found in soil, water, and food (raw and lightly cooked meat or fish). Rare cases of the disease occur due to insect bites. The mechanism of helminthiasis infection is oral-fecal. A person ingests parasite eggs with food and water. Contact and household methods of infection also occur. They occur when, after contact with soil or sand, your hands were not washed properly.

Vegetables and berries that grow in the ground and are not washed enough are also a source of worm infection. Children who play with pets and garden animals are at risk of contracting worms. Pets that roam freely on the streets can bring helminth eggs into the house. Flies and other insects, after contact with animal feces and landing on food, can easily transfer helminth eggs. Surprisingly, person-to-person transmission is also possible. It happens like this: a female pinworm can emerge from the intestines and lay eggs directly on underwear, causing intense itching. A person, after scratching an itchy area, may come into contact with other toiletries and household items. These objects fall into the hands of other family members, after which they become infected.

Infection through water is also possible. Many parasite eggs fall easily into open reservoirs and pits. Drinking unboiled well water is extremely dangerous.

Types of helminthiasis

Helminthiases differ in the method of penetration into the human body:

  1. Biohelminths
  2. Geohelminths
  3. Contagious

Biohelminths are transmitted to people through contact with animals. Geohelminths can become infected through soil. Contagious ones arise from contact with an infected person. The disease manifests itself in different ways depending on the method of infection, the number of worms and the degree of adaptation in any human organ.

Stages of helminthiasis

Adult egg and helminth

The most destructive effect on the body is caused not by adults, but by their larvae. Adult individuals have already chosen a cozy place on the human body, and the larva crawls through the organs and leaves their lesions. The most common habitat for parasites is the gastrointestinal tract. Different types of parasites prefer different habitats. So, the nematodes settle in the small intestine and the pinworms settle in the large intestine and the lower parts of the small intestine. Depending on the habitat of the parasites, helminth infections are:

  • Translucent
  • Fabric

The luminals are found in the lumens of the genital organs and the tissue ones are found within the tissues. Depending on their growth, parasites can change their habitat, going from the luminal form to the tissue form. Helminthiasis develops in two stages:

  1. Spicy
  2. Chronic

The acute stage lasts from a week to a month and the chronic stage continues until healing. The acute stage begins with the introduction of the egg and continues as the parasite matures and grows. The disease manifests itself as allergic reactions to a foreign organism. During the chronic stage of the disease, various reactions of the body occur. During this period, the parasite moves through the body in search of refuge. The disease is accompanied by alterations in the functioning of organs and systems of the human body. By integrating into the human body's immune system, parasites consume substances necessary for their growth and development. This causes metabolic disorders, disorders of the digestive system and difficulty absorbing vitamins and minerals.

In addition to this damage, parasites throw their waste products into the human body, poisoning it and causing intestinal disorders, decreased immunity and the development of bacterial infections. Parasites contribute to the risk of developing cancer. This happens due to the negative impact on the immune system and the stimulation of cell division. Often a patient is examined by many specialists who find a number of diseases in him. And in this case, all specialists can be replaced by a single doctor - the parasitologist.

Classification of helminths.

Roundworms are quite common in the human intestine.

Types of worms in humans:

  1. flatworms
  2. Intestinal worms

Flatworms include:

  • Trematodes (opisthorchiasis, schistosomes, paragonimus)
  • Cestodes (broad tapeworm, pork tapeworm, echinococcus, alveococcus)
  • Intestinal worms or nematodes:
    • intestinal worm
    • roundworms
    • Hookworm
    • Trichinella

This classification of helminths is presented in the medical literature. To successfully solve a problem such as helminthiasis, it is necessary to know in depth the characteristics of the structure and life cycle of parasites.


Another name for trematodes is trematodes. These parasites have a flat or lanceolate leaf shape with two suction cups. One suction cup is located in the mouth and the second, which serves as fixation, is in the peritoneum. All trematode representatives enter the body through an intermediate host. Most of these parasites are hermaphrodites.


This is a fluke: a worm up to 1. 3 cm long with two suction cups. Opisthorchiasis is a hermaphrodite that parasitizes the liver, gallbladder and pancreas in humans and some carnivorous animals (foxes, dogs, cats). Opisthorchiasis eggs leave the human or animal body through feces. When these eggs enter a body of water, they are swallowed by freshwater mollusks, within which the larvae hatch and develop. The process of development and maturation of the larvae lasts two months. The larvae then emerge from the mollusk and penetrate the skin of the carp. After six weeks, the larvae develop into mature, mature parasites. Opisthorchiasis enters the body of an animal or person after eating contaminated fish. This worm can live in a living organism for up to 20 years. Symptoms of opisthorchiasis:

  1. Allergy
  2. Weakness
  3. Headache
  4. Dizziness
  5. Depression
  6. Loss of consciousness

Damage caused to the body by opisthorchiasis:

  • Poisoning by parasite waste products
  • Damage to liver tissue.
  • Damage to the gallbladder
  • Altered bile output.
  • Inflammation of the pancreas
  • Secretory dysfunction
  • Decreased gastric motility.
  • Thickening of the walls of some organs, resulting in the appearance of tumors.

The chronic course of the disease is characterized by:

  • Heaviness after eating
  • Pain
  • Vomiting
  • Nausea

Prevention of infections: To avoid infection with opisthorchiasis, you should not eat raw fish. The larvae die during heat treatment of products. Dried fish can only be consumed if it has been previously salted. Additionally, the larvae die when the fish remains frozen for a long time.


Garlic is an effective anthelmintic.

These parasites are of different sexes, similar to needles with a length of 0. 4 to 2. 6 cm, females are longer than males and larger in size, producing 3000 eggs per day. The reproduction method is the same as that of the previous type of parasite, through freshwater mollusks. The larva enters the human body through the skin and mucous membranes while swimming in a body of fresh water. It can also enter the body of a person who accidentally swallows water while swimming. After a day of penetration, the larva turns into an adult and enters the peripheral veins, through which it is sent to the lungs and venous vessels. There the schistosome reaches sexual maturity.

Schistosoma lays eggs in the intestines, mucous membranes and bladder. The eggs are then excreted from the human body through urine or feces and begin their development process again. Schistosoma lives in the human body for several decades, causing damage and infecting new individuals. The problems that arise when infected with schistosomes are not caused in the human body by adults, but by their eggs. Only half of the eggs are excreted from the body, the rest accumulate in the organs. The eggs of this parasite have spines that damage a person's internal organs, often causing ulcers in the infected person. Patients with schistosomiasis experience the following symptoms:

  • appetite disturbance
  • Anemia
  • enlarged liver
  • changed spleen
  • Decreased intestinal motility.
  • Stomachache
  • Constipation
  • Diarrhea
  • Weightloss
  • intestinal bleeding
  • Pain when urinating
  • Allergies
  • Weakness

When the genitourinary system is infected, patients experience:

  1. Menstrual irregularities and spontaneous abortions in women.
  2. Impotence and incomplete ejaculation in men.

If the eggs enter the central nervous system:

  • Acute cerebral schistosomiasis
  • Chronic brain damage
  • Death

Infected children experience delays in growth and development and lower performance in school. Prevention of the disease includes avoiding swimming and walking barefoot in tropical waters.


Preventing worm infection hand washing

Paragonim is a 1 cm long lung fluke with an ovoid body and red spines. This parasite multiplies in the lungs of animals and enters the human body when eating crayfish and freshwater crabs. The parasite affects the respiratory system. Patients with paragonimiasis are characterized by allergic reactions and decreased immunity. Symptoms:

  • Temperature increase
  • Cough
  • Production of sputum from the lungs when coughing.
  • dyspnoea
  • In severe cases, there is blood and parasite eggs in the sputum.
  • Wheezing can be heard clearly in the patient's lungs.

Prevention: Avoid eating raw crabs and crabs.


Representatives of cestodes are tapeworms of various lengths. Some parasites reach gigantic sizes. On the head of these parasites there are suction cups, hooks or suction slits. Parasites need these devices to adhere to the intestinal walls. Cestodes affect the entire human body; They are more dangerous for children, who quickly develop anemia.


These parasites reach a length of 5 cm and are the causative agents of the Echinococcus disease. The multi-chambered representative of this type of worm is the causative agent of a disease such as alveococcosis. The disease is transmitted by cattle and domestic animals. When caring for these animals, parasite eggs fall from their fur into people's hands. When parasites enter the human intestine, they bite the mucous membrane. As the parasite matures, it develops 4 sections, the last of which is filled with eggs. These sections break off and spread throughout the body, infecting it. The fourth section spreads the eggs throughout the body.

The patient's infected organ increases in size, for example the liver. Suppuration may form. An enlarged organ can even rupture the abdominal cavity. And this can lead to severe sepsis of the body and even death. Symptoms:

  • Weakness
  • Dizziness
  • Allergic reactions to parasite waste products.

Echinococcus affects:

  1. Brain
  2. Spinal cord
  3. Eyes
  4. Thyroid gland
  5. Liver
  6. Lungs
  7. Uterus

This parasite can cause the formation of tumors, including malignant ones. The most unpleasant thing is that the treatment of this disease is only possible through surgery. Prevention: personal hygiene in contact with animals.


These worms with an elongated, round or cylindrical body, most frequently parasitize the bodies of children. These nematodes include pinworms, roundworms, and hookworms.


Giardia are parasites too!

They are small white worms. The length of the female is 1 cm, the male is 0. 5 cm. These parasites have a pointed tail, which is why they were called pinworms. The habitat of pinworms is the human intestine. The front end of the parasite has a suction cup, with which the pinworm pierces the intestines, and the sharp end hangs in the lumen and damages the walls. This disease is called enterobiasis. A person can become infected with dirty hands. The disease is observed in preschool children attending kindergarten. A symptom of pinworm infection is itching near the anus. More often, itching is felt at night, when the female lays eggs and secretes a special substance. Symptoms:

  1. Itching
  2. Diarrhea
  3. Stomachache
  4. Headache
  5. Lack of appetite

Prevention: hand washing.

Intestinal worms

These worms are the largest. The length of the female is up to 0. 5 m and she lays 200 thousand eggs per year, regardless of the male. The infection mechanism is fecal-oral. Ascaris eggs enter the human body along with unwashed vegetables and fruits, through dirty hands. The larva, entering the intestine, separates from the shell and penetrates the intestinal walls, while migrating through the intestinal veins to the liver, through the hepatic veins to the heart, through the pulmonary arteries to the bronchi, then to the trachea and mouth. A part of the larvae dies in the open air and the rest is devoured. Symptoms:

  • Nausea
  • Vomit
  • Jaundice
  • Pancreatitis
  • Frequent acute respiratory infections
  • Bronchitis
  • Pneumonia


  • Handwashing
  • Wash vegetables and fruits.
  • Maintain personal hygiene
  • Protect food from flies, cockroaches and other carriers.

In conclusion, we can say that the cause of the disease is not always the bacteria and viruses that have entered the body. Parasites can cause enormous damage to human health. If unclear symptoms appear, the possibility of a parasite entering the body should not be excluded; the patient should visit a parasitologist.