Types of worms in humans and ways to infect them

Worms are representatives of the lower worms that live in the human body. The disease associated with the infection of a person with various types of worms is called helminthiasis. This disease is not uncommon and affects certain segments of the population. Children are susceptible to infections with pinworms, 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 infection with helminthiasis. To date, the theory of 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, nevertheless, patients with this disease 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 ailments is helminthiasis.

How does the infection occur

Worms cause a lot of trouble for a person

parasites in the human body

Helminth infection occurs as follows:

  • Through unwashed hands
  • In contact with the ground
  • after insect bites
  • Because of dirty hands
  • When you eat raw meat and fish
  • After eating unwashed fruits and vegetables
  • After contact with an animal
  • After contact with infected people

Mature eggs of parasites can be found in soil, water, food (raw and poorly heat-treated meat or fish). Rare cases of the disease are due to insect bites. The mechanism of infection with helminthiasis is fecal-oral. A person swallows parasite eggs with food, water. Household contact methods of infection also occur. They occur when, after contact with the ground or sand, the hands have not been thoroughly washed.

Vegetables and berries growing in the ground, which are not sufficiently washed, are also a source of worm infection. Children who play with the yard and pets are at risk of getting infected with worms. Pets roaming the streets freely can bring helminth eggs into the house. Flies and other insects, after contact with animal feces, sitting on food, can easily transfer helminth eggs. Surprisingly, human-to-human transmission is also possible. It happens like this: the female pinworm can crawl out of the intestines and lay eggs directly on the underwear, causing severe itching. A person, having combed an itchy place, can come into contact with other toiletries and household items. These objects fall into the hands of other family members, after which they become infected.

Waterborne infection is also possible. Many parasitic eggs easily fall into bodies of water and open wells. Drinking unboiled well water is extremely dangerous.

Types of helminthiasis

Helminthiases differ in how they enter the human body:

  1. Biohelminths
  2. Soil-transmitted helminths
  3. contagious

Biohelminths are transmitted to humans through contact with animals. Soil-transmitted helminths can be infected through the soil. Contagious result from contact with an infected person. The disease manifests itself differently depending on the method of infection, the number of worms, the degree of their adaptation in any human organ.

Stages of helminthiasis

how does a worm infestation occur

The most destructive effect on the body is produced not by adults, but by their larvae. Adult individuals have already chosen a comfortable place for themselves in the human body, and the larva travels through the organs and leaves its lesions. The most common habitat for parasites is the gastrointestinal tract. Different types of pests prefer different habitats. So, roundworms are located in the small intestine, and pinworms settle in the large intestine and the lower parts of the small intestine. Depending on the habitat of the parasites, helminthiasis are:

  • translucent
  • Fabric

Translucent ones are located in the lumens of the genitals, and tissues - inside the tissues. Depending on the growth, the parasites can change their habitat, changing from the translucent form to that of the tissues. Helminthiases develop in two stages:

  1. acute
  2. Chronic

The acute phase lasts from a week to a month and the chronic phase continues until recovery. The acute phase begins with the introduction of the egg and continues as the parasite matures and develops. The disease is manifested by allergic reactions to a foreign organism. During the chronic phase of the disease, various reactions of the body occur. During this period, the parasite moves through the body in search of shelter. The disease is accompanied by disturbances in the functioning of organs and systems of the human body. Embedded in the immune system of the human body, the parasites consume the substances necessary for their growth and development. This leads to metabolic disorders, disorders of the digestive system, difficulties in the absorption of vitamins and minerals.

In addition to this damage, the parasites release their waste products into the human body, poisoning the body, leading to intestinal disorders, reduced 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 the cell division process. Often a patient is examined by many specialists who find in him a bunch of diseases. And in this case, a single doctor, a parasitologist, can replace all the specialists.

Classification of helminths

ascaris in humans

roundworms are quite common

Types of worms in humans:

  1. flatworms
  2. roundworms

Flatworms include:

  • Trematodes (opisthorchis, schistosomes, paragonim)
  • Cestodes (large tapeworm, tapeworm, echinococcus, alveococcus)
  • Roundworms or nematodes:
  • Pinworm
  • Ascaris
  • hookworm
  • Trichinella

Such a classification of helminths is presented in the medical literature. To successfully solve such a problem as helminthiasis, it is necessary to find out a thorough description of the structure and life cycle of parasites.


Another name for trematodes is flukes. These parasites are flat, leaf-like or lanceolate with two suckers. One suction cup is in the mouth, and the second, which serves as a fixation, in the peritoneum. All representatives of the flukes enter the body through an intermediate host. These parasites are mostly hermaphrodites.


This fluke is a worm up to 1. 3 cm long with two suckers. Opisthorchis is a hermaphrodite, parasitizing the liver, gallbladder, pancreas in humans and in certain predatory animals (foxes, dogs, cats). Opisthorchiasis eggs leave the human or animal body with feces. When they enter the tank, these eggs are swallowed by freshwater snails, inside which the larvae hatch and develop. The process of development and maturation of the larvae lasts two months. Then the larvae crawl out of the mollusk and penetrate under the skin of the carp. After six weeks, the larvae become full-fledged mature parasites. Opisthorchis enters the body of an animal or a person after eating infected 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. The Depression
  6. Loss of consciousness

Damage to the body caused by opisthorchiasis:

  • Parasite waste poisoning
  • Liver tissue damage
  • Gallbladder injury
  • Violation of the outflow of bile
  • Inflammation of the pancreas
  • Secretory dysfunctions
  • Decreased stomach motility
  • Thickening of the walls of certain organs, the appearance of tumors as a result.

The chronic course of the disease is characterized by:

  • Heaviness after eating
  • Pains
  • To vomit
  • Nausea

Opisthorchi habitats in fish-rich rivers:

  1. Kame
  2. Dnipro
  3. Neman Delta

Prevention of infection: To avoid infection with opisthorchiasis, do not eat raw fish. Larvae die during heat treatment of products. Dried fish can only be eaten if it has been salted beforehand. Also, the larvae die when the fish is frozen for a long time.


garlic for worms

These parasites are of different sexes, they look like a needle 0. 4-2. 6 cm long. The females are longer than the males and larger, they produce 3000 eggs per day. The method of reproduction, as in the previous species of parasites, is through freshwater molluscs. The larva enters the human body through the skin, mucous membranes while swimming in a reservoir of fresh water. It can also enter the body of a person who has accidentally swallowed water while swimming. A day after penetration, the larva turns into an adult and enters the peripheral veins, through which it is directed to the lungs and venous vessels. There, the schistosome reaches sexual maturity.

Schistosoma lays eggs in the intestines, mucous membranes, bladder. Then the eggs are excreted from the human body with urine or feces and start the development path again. Schistosoma lives in the human body for several decades, causing damage and infecting new individuals. The problems that arise during schistosome infection, the human body is no longer caused by adults, but by their eggs. Only half of the eggs are excreted from the body, the rest accumulates in the organs. The eggs of this parasite have spikes that damage the internal organs of a person, often ulcers occur in infected people. Patients with schistosomiasis have the following symptoms:

  • Appetite disorder
  • Anemia
  • enlarged liver
  • altered spleen
  • Decreased intestinal peristalsis
  • Stomach ache
  • constipation
  • diarrhea
  • Weightloss
  • Intestinal bleeding
  • Pain during urination
  • allergic
  • Weakness

When the genitourinary system is infected, patients experience:

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

When the eggs enter the central nervous system:

  • Acute cerebral schistosomiasis
  • Chronic brain damage
  • Fatal outcome

Infected children experience delayed growth and development, reduced school performance. Prevention of disease involves avoiding swimming and avoiding walking barefoot in tropical waters.


wash your hands against parasites

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 by eating crayfish, freshwater crabs. The parasite infects the respiratory system. For patients with paragonimiasis, allergic reactions and decreased immunity are characteristic. Symptoms:

  • Temperature rise
  • Cough
  • Excretion of sputum from the lungs when coughing
  • Dyspnea
  • In severe cases, blood and parasite eggs are present in the sputum.
  • In the patient's lungs, wheezing is clearly audible.
  • Prevention: Exclude the use of raw crayfish and crabs.


Representatives of cestodes are tapeworms of different lengths. Some parasites reach gigantic sizes. On the head of these parasites there are suction cups, hooks or suction slots. These adaptations are necessary for the parasites to adhere to the walls of the intestine. Cestodes affect the entire human body, they are most dangerous for children who quickly develop anemia.


These parasites reach a length of 5 cm and are the causative agents of Echinococcus disease. A multichamber representative of this type of worm is the causative agent of such a disease as alveococcosis. The disease is transmitted by cattle and domestic animals. When caring for these animals, the eggs of the parasite fall from their fur into the hands of humans. Getting into the human intestine, the parasites bite into the mucous membrane. As the parasite matures, 4 sections appear, the last of which is filled with eggs. These departments break off and scatter throughout the body, infecting it. The fourth section scatters the eggs throughout the body.

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

  • Weakness
  • Dizziness
  • Allergic reactions to parasite waste.

Echinococcus affects:

  1. Brain
  2. Spinal cord
  3. Eyes
  4. thyroid gland
  5. Liver
  6. Lungs
  7. uterus

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


These worms with an elongated, round or cylinder-shaped body most often parasitize in the body of children. These roundworms include pinworms, roundworms, hookworms.


Giardia in the human body

These are small white worms. The length of the female is 1 cm, that of the male - 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 sucker, with the help of which the pinworm pierces the intestines, and the pointed end hangs in the lumen and damages the walls. This disease is called enterobiosis. You can get infected from someone with dirty hands. There is a disease in preschool children attending kindergarten. A symptom of pinworm infection is itching around the anus. Most often, itching is felt at night, when the female lays eggs, while releasing a special substance. Symptoms:

  1. Itching
  2. Diarrhea
  3. Stomach ache
  4. Headache
  5. Lack of appetite
  6. Prevention
  7. hand washing


These worms are the biggest. The length of the female can reach 0. 5 m. The female lays 200, 000 eggs per year, regardless of the male. The mechanism of infection is fecal-oral. Ascaris eggs enter the human body together with unwashed vegetables and fruits through dirty hands. The larva that has entered the intestine is selected from the shell and penetrates the walls of the intestine, migrating through the intestinal veins to the liver, through the hepatic veins to the heart, through the pulmonary arteries to the bronchi, then into the trachea and into the mouth. A partial number of larvae die in the open, the rest are swallowed upside down. Symptoms:

  • Nausea
  • To throw up
  • Jaundice
  • pancreatitis
  • Frequent acute respiratory infections
  • Bronchitis
  • Pneumonia


  • hand washing
  • Wash vegetables and fruits
  • Personal hygiene
  • Protect food from flies, cockroaches and other peddlers.

In conclusion, it can be said that the cause of the disease is not always the bacteria and viruses that have entered the body. Parasites can cause serious harm to human health. In case of unclear symptoms, it is not necessary to exclude the penetration of the parasite into the body, the patient should consult a parasitologist.