Helminths: what parasitic worms are dangerous for humans

According to the WHO, every year one in two people on the planet is infected with helminths. Many people think that parasitic worms are not very harmful to your health. However, not everything is so simple: helminths can infect important internal organs: heart, lungs, brain.

Helminths - who are they?

Helminths are parasitic worms that can choose the body of a person, animal, plant as a host. There are three classes of helminths in total:

  • tapeworms.This class includes about 3, 5 thousand types of helminths. The length of parasitic worms varies from a few mm to 10-15 meters;
  • water pit.Parasites get their name from the presence of suckers, with the help of which they receive nutrients. The human body can infect about 4 dozen species of fluke. As a rule, the length of the worms does not exceed 5 cm;
  • roundworms.This class of helminths has more than 24, 000 species. Roundworms are spindle shaped. Usually their length does not exceed 0. 5 meter.

You can get infected with helminths in different ways. However, parasite invasion most often occurs for the following reasons:

  1. Poor hand hygiene.
  2. Unwashed vegetables, fruits; Undercooked or undercooked meat and fish - the use of these products increases the risk of parasite infestation repeatedly.
  3. Keep foods open outside the refrigerator. Insects are able to transfer helminth eggs to food stored without packaging.
  4. Contact with domestic animals.
causes of infection of the body with parasites

The main symptoms of the presence of parasites in the body:

  • nausea, vomiting, diarrhea;
  • weightloss;
  • allergic rashes;
  • bloating;
  • itching in the anus;
  • cringe in a dream.

Which helminths are most common in Russia? Consider the most common types of parasitic worms and the diseases they cause.

Tapeworms

The body of the tapeworm consists of elements, the total number of which varies from 3 to 5000. The main element of attachment of the helminth is the head, the others are suction cups, hooks.

The most common causes of tapeworms are:

  • diphyllobothriasis;
  • teniarinhoses;
  • tapeworm.
tapeworm, a parasite of the human body

Diphyllobothriasis

The causative agent of the disease is a large tapeworm which affects the human intestine. The development of worm eggs occurs in fresh water. The scheme of tapeworm entering the human body is as follows:

  • The eggs of the worm are swallowed by crustaceans that live in the tank.
  • Infected crustaceans are eaten by fish.
  • A person becomes infected with a parasite by eating fish that has undergone insufficient heat treatment.

Symptoms of the disease develop 1. 5 months after infection. The main sign of pathology is the presence of whitish fragments of helminths in the stool.

Attaching to the intestinal lining, the tapeworm absorbs a large amount of vitamin B12. Because of this, people with diphyllobothriasis often develop anemia. In addition, tapeworm can cause an increase in the liver, spleen, intestinal obstruction.

Teniarinhoz

The causative agent of the disease is bovine tapeworm, which lives mainly in the human small intestine. During its development cycle, the helminth replaces two hosts: the intermediary is cattle, the main one is humans. Bovine tapeworm can live in the body for 20 years, multiplying and causing damage to health.

Typically, people develop teniarinhoses after eating undercooked or undercooked beef.

The disease often proceeds without pronounced symptoms and is detected by chance when a person sees elements of helminths in their feces. In some people, in addition to the main signs of helminth infection, pain syndrome may occur on the right side of the anterior abdominal wall.

Adult helminths are able to enter the appendix, pancreatic duct, bile ducts, causing acute inflammatory processes in them. With multiple parasitic infestations, intestinal obstruction can develop.

bovine tapeworm parasite

Tapeworm

The causative agent of the disease is the pork tapeworm, which initially affects the human small intestine. Human infection occurs through the consumption of raw or undercooked pork.

The parasite can enter various organs and tissues, causing pain in the abdomen, back and limbs. Pathology is most favorable when the worm is localized in subcutaneous fat and skeletal muscle tissue. When the worms enter the eye muscles, they cause decreased visual acuity, tearing, and photophobia. The defeat of the porcine chain of the brain can be fatal.

suction cups

Moats are leaf-shaped and have a great ability to reproduce at different times of the life cycle. Reproduction of worms is possible not only sexually with fertilization, but also without it. In addition to suckers, worms have many hooks and thorns, thanks to which they reliably attach themselves to the mucous membranes of organs.

fluke parasite species

Common pathologies caused by fluke:

  • fascioliasis;
  • opisthorchiasis;
  • paragonimiasis.

Fascioliasis

Fasciolosis occurs when the liver or gallbladder is damaged by the liver fluke. Basically, the infection occurs during the consumption of vegetables, for which water has been used from open tanks.

In addition to the standard signs of parasitic infection, a person may experience asthma attacks, which are accompanied by shortness of breath, flushing of the face, dilated pupils, and tachycardia. If an adult has caused obstruction of the bile ducts, obstructive jaundice develops. Signs of pathology:

  • cramps in the right hypochondrium;
  • yellowing of the skin;
  • fever;
  • colorless feces.

Opisthorchiasis

The causative agent of the disease is a feline fluke. The name of the parasite is due to the fact that in addition to humans, it often infects cats and other mammals that eat fish.

feline fluke parasite

Typically, feline fluke affects the liver and pancreas, causing inflammation of the organs. The symptoms are varied and depend on the number of parasites. The patient may experience:

  • symptoms of intoxication;
  • fever;
  • urticaria;
  • itchy skin;
  • pain in muscles, joints, right hypochondrium.

In some cases, helminths cause an increase in lymph nodes, the development of jaundice. The chronic form of pathology often leads to hepatitis, cirrhosis of the liver.

Paragonimosis

The culprit of the disease is a lung fluke, which enters the human body along with infected crustaceans.

First, the parasite enters the human intestine, and then the abdominal cavity. The end point of its journey is lung tissue. In addition, the worm is able to enter the brain and affect the central nervous system.

fluke lung parasite

Specific signs of parasitic invasion of the lungs:

  • pain in the chest;
  • cough with phlegm, which may contain pus and blood;
  • fever.

In some cases, helminths provoke a violation of the ventilation function of the lungs and gas exchange during breathing.

Round worms

Due to their structure, roundworms (nematodes) are able to survive even under extreme conditions. Their body is covered with a three-layered musculo-skin sac, which reliably protects parasites from external influences.

type of parasitic roundworm

Common diseases caused by nematodes:

  • ascariasis;
  • enterobiosis;
  • trichinosis.

Ascariasis

The development of the disease causes roundworms, which initially attach themselves to the small intestine. The average length of adults is 40 cm. The larvae of the parasite can enter the human digestive system with unwashed vegetables and fruits, contaminated water. In addition, improperly washed hands before eating are often the cause of ascariasis.

When the larvae enter the human body, a subfebrile temperature, allergic rashes and cough with the release of clear sputum can be observed. Signs of the intestinal stage of ascariasis (diarrhea, abdominal pain) are observed only in the presence of several parasites. Typically, living in the intestines of a worm is asymptomatic.

Complications with multiple parasitic infestations:

  • blockage of the bile duct;
  • purulent inflammatory processes in the gallbladder, liver;
  • inflammation of the appendix;
  • intestinal obstruction.

Enterobiosis

The provocateurs of the disease are pinworms - small worms up to 1 cm long. Helminths enter the human digestive system in the same way as roundworms.

human pinworm parasites

Currently, enterobiosis is the most common parasitic pathology in the world. Basically, the disease is diagnosed in children under the age of 10.

Symptoms, as in previous cases, only develop with multiple parasitic infestations. Children often have diarrhea, mucus in their stools, difficult and painful digestion, itching in the anus, and nausea. With a severe course of the disease, limb cramps may occur. In addition, pinworms are able to enter the genitals, causing acute inflammation in them.

Trichinosis

This disease causes Trichinella - one of the smallest parasitic worms. The length of the parasite rarely exceeds 4 mm. In the larval stage, the worms can infect skeletal muscles. The exception is the myocardium - the muscle tissue of the heart. Adults parasitize the small intestine.

Typically, human infection occurs when eating half-cooked pork. At the same time, for the development of the disease it is enough to consume only 30 g of meat affected by parasites.

The pathology is manifested by the standard symptoms of parasitic invasion. At an advanced stage, swelling of the eyelids, face, arms and legs, pain in the lower back, chewing muscles may occur. Possible complications are total or partial loss of mobility, paralysis of the respiratory tract.

How to avoid helminth infestation?

To reduce the risk of becoming infected with parasitic worms, it is important to follow these guidelines:

  1. Wash hands thoroughly before eating, after visiting the street, public places.
  2. Observe the appropriate technology for cooking meat, fish. Heat treatment of meat and fish products should take at least 20 minutes.
  3. Do not eat dried or cured fish.
  4. Perform deworming of domestic animals.
  5. Get tested regularly, even if you don't have any signs of illness. The most common diagnostic methods are gross and microscopic examination of feces. The first method allows you to detect adults, the second - eggs and larvae of worms.