Not everyone knows the dangers of having helminths in the body, the types of worms and how to infect people.Some parasites can live in the human body without causing any problems.Up to 90% of adults and children do not even suspect that they are infected with worms.Helminths are of great medical importance, as they can be transmitted from person to person and cause dysfunction of internal organs.
The most common types of helminths
Worms in humans are parasitic worms that live in organs and live at the expense of their host.There are several hundred species of them.In some countries, laboratory tests can only detect some of them.The following types of worms are distinguished:
- nematodes (roundworms);
- cestodes (tapeworms);
- trematodes (flukes).
There are luminal and tissue parasites.The first are distinguished by the fact that they live in the lumen of a hollow organ (intestine, bile ducts).Tissue worms in humans live in the thickness of tissues.There are worms that belong to two groups at once.These are roundworms.Adults live in the lumen of the small intestine, and larvae can infect the lungs and liver.
The classification of helminths includes the division of worms not only by habitat, but also by characteristics of the life cycle.To complete development, some parasites require intermediate hosts (mollusks, fish, animals), in which the larvae mature.Such worms belong to the group of biohelminths.Some parasitic worms need to be exposed to the external environment (water or soil).This is how geohelminths develop.
Contact types of helminthiasis are separately identified.These include hymenolepiasis and enterobiasis.Infection with pinworms and dwarf tapeworms is possible through contact with a sick person.There are intestinal and extraintestinal worms.The first group includes pinworms, roundworms, tapeworms, and whipworms.Other parasites (fasciola, flukes, echinococci, trichinella, alveococci) affect other organs.
Helminths from the group of nematodes
Various types of helminths are known.The most common are roundworms (nematodes).They belong to the type of protocavitary worms.Human nematodes are arranged as follows:
- have a body that is not divided into segments;
- of various sizes;
- thread-like or spindle-shaped;
- have a skin-muscle sac and cuticle;
- have a digestive system in the form of a through tube;
- dioecious;
- capable of laying eggs.
Most often, the presence of these worms in humans is manifested by gastrointestinal disorders.The most common nematodes that parasitize the human body are pinworms, roundworms, hookworms (hookworms and hookworms) and whipworms.According to WHO, more than 1 billion people suffer from enterobiasis.Young children are more likely to get sick.
A person can become infected with pinworms anywhere.This is due to the widespread distribution of the eggs of these helminths.Transmission factors include toys, household items, pens, pencils, unwashed food, dirty hands, bus railings, and telephones.Of all types of helminths, pinworms are the most frequently detected.
These parasites reach a length of 1 cm and have a thin body with a sharp end.They are attached to the intestines.Young children who attend kindergartens are more likely to get sick.Pinworms live in the human body for 1-2 months.A person can become infected not only with enterobiasis, but also with ascariasis.Often these diseases are detected simultaneously.Roundworms are larger (20-40 cm).
These are geohelminths, the eggs of which develop and remain in the soil for a long time.The method of infection is oral.This happens when in contact with the ground, when drinking untreated water, or eating vegetables and fruits contaminated with feces.Very often worms such as whipworms are detected.This is the causative agent of trichuriasis.They have a thin body, reminiscent of hair.The back of the parasite is thickened.
These helminths reach a size of 55 cm. They parasitize the large intestine.Up to 30% of the population is infected with hookworms.These are geohelminths that are common mainly in countries with warm climates.They are otherwise called crooked heads.These worms are parasitic only in humans.Their body length reaches 14 mm.Hookworms can live up to 15 years, and hookworms can live up to 8 years.
Representatives of tapeworms
Doctors often have to deal with tapeworms.They are called cestodes.The peculiarity of this type of worm is that their body is divided into segments.This group includes various tapeworms (dwarf, bovine and pork), as well as broad tapeworm.In children under 14 years of age, the causative agent of hymenolepiasis is often detected.This is a dwarf tapeworm.
This type of helminth has the following distinctive features:
- up to 5 cm in size;
- parasitizes mainly in the intestines;
- has a head (scolex), neck, body (strobilus), 4 suckers and hooks;
- divided into segments;
- develops completely in the human body.
Along with pinworms, the dwarf tapeworm is a contact helminth.Parasite eggs can be spread by insects (flies).There are varieties of cestodes that reach 20 m or more.A prominent representative is the broad tapeworm.This is the causative agent of diphyllobothriasis.This worm belongs to the group of biohelminths.
To complete its life cycle and become an adult, it needs to enter the body of intermediate hosts (fish and crustaceans).The peculiarity of this parasite is that its long stay in the human body leads to persistent anemia due to a lack of vitamin B12.Diphyllobothriasis most often affects people who love fish.These parasites infect people living near fresh water bodies and fishing.The broad tapeworm is capable of living in the human intestine for 20 years or more.Animals (cats, dogs, bears) can also act as the final host.
Often infection occurs with worms called echinococcus.They live in the human body in the form of larvae.Humans are intermediate hosts and at the same time a dead-end branch in the development of helminths.Infection occurs through consumption of meat from contaminated game or domestic animals, unwashed vegetables and fruits.Echinococci are unilocular and multilocular.
The latter are called alveococci.These cestodes are most often localized in the liver and lungs, forming cysts.They are bubbles with a liquid substance and scolex (heads) of the parasite.Massive liver damage can lead to tissue compression.If the cyst membrane ruptures, there is a risk of shock.There are other types of helminths from the cestode group: bovine and pork tapeworms.They are the causative agents of taeniasis and teniarynchosis.
Worms from the group of trematodes
Only doctors know what worms are.Flukes (flukes) are very common.These include schistosomes, fasciolas and cat flukes.These types of helminths have the following features:
- small size;
- equipped with suction cups;
- leaf-shaped or round in shape (with the exception of schistosomes).
The following groups of flukes are distinguished:
- blood;
- hepatic;
- pulmonary;
- intestinal.
Most often, these parasites affect other organs rather than the intestines.Infection with worms such as schistosomes can cause damage to the urinary tract (kidneys, bladder), liver and other organs.More than 300 million people are infected with schistosomes.These are small (up to 2 cm) parasites with an elongated body.Men get sick more often than women.
Schistosomes affect the veins, kidneys, bladder, ureters, and abdominal organs.They feed on blood.Schistosomes are biohelminths.They develop in the body of freshwater mollusks.Their peculiarity is the ability to actively leave the vessels and be excreted with metabolic products (urine and feces) into the environment.Schistosomiasis causes cystitis, anemia, lymphadenopathy, damage to the liver, kidneys and genitals.
Rare types of parasites in the human body include fasciola (liver and giant flukes).Some individuals reach a size of 10 cm. Humans become infected through sick herbivores through the nutritional route by eating salads and greens growing near stagnant bodies of water.Raw water can also be a transmission factor.
Fasciolas are hermaphrodites.They affect the bile ducts, leading to the development of cholestasis and liver fibrosis.In severe cases, hepatitis or cholecystitis occurs.One of the endemic helminths of humans is the cat fluke.It causes opisthorchiasis.The reason is eating infected fish.
Worms transmitted through meat
Not everyone knows what types of worms are transmitted through meat.This group includes worms such as bovine and pork tapeworms, echinococcus, and trichinella.A pathology such as trichinosis can lead to serious consequences.This is a disease caused by small roundworms.Trichinella enters the human body through food.
The following products are dangerous:
- kebabs;
- game (bear meat, wild boar);
- pork;
- homemade sausage;
- homemade lard;
- steaks and medium-cooked meats;
- bacon;
- brisket;
- hams
It is not recommended to eat the meat of walruses, seals and nutria.Those at risk include hunters, tourists, livestock farmers and people who cook meat poorly or undercook it.Trichinosis is characterized by a severe allergic reaction, edema syndrome and muscle damage.In severe situations, death is possible.
Meat is a factor in the transmission of bovine and pork tapeworms.People become infected by eating pork or beef that contains the helminth.This is an intermediate (larval) form of development of the parasite.Adult pork tapeworms reach 4 m in length, and bull tapeworms - 20 m.
The following risk factors for infection with taeniasis and taeniarinhoz are identified:
- lack of veterinary supervision;
- poor heat treatment of meat;
- livestock breeding (cows, pigs);
- unsanitary conditions;
- infection with cysticerci of water.
Most often, only 1 adult tapeworm lives in the intestines of sick people.Despite this, the parasite can cause digestive disorders and intestinal obstruction.The presence of these helminths in humans can be detected by examining stool.A special feature of the bovine tapeworm is that its segments are able to crawl out and actively move during bowel movements.
Herbivores themselves become infected by eating grass contaminated with the feces of sick animals.Finns (cysticerci) are formed in the body of livestock (pigs and cows).When buying and cutting meat, they can be easily detected.They are round in shape and yellow in color.A person infected with bovine tapeworm is not dangerous to others.
Helminths transmitted through fish
There are several types of worms that can be contracted by eating undercooked or undercooked fish.The human body requires different products.Millions of people around the world consume freshwater fish, caviar and milt.They are at risk of contracting diphyllobothriasis and opisthorchiasis.
In some regions, tapeworm and cat fluke are endemic helminths.The reason is active fishing and infection of fish.Up to 75% of the population is infected with opisthorchiasis.These parasites also infect animals (cats, foxes, dogs).Infection occurs when eating half-raw fish (carp, bream, roach, ide) infected with parasite larvae.
Risk factors include rapid frying of infected raw materials, consumption of lightly salted, dried or raw fish, caviar, and kebabs.The mechanism of infection is nutritional.The cat fluke belongs to the group of flukes.This helminth does not exceed 2 cm in length.These worms cause stagnation of bile, inflammation of the pancreas, hepatitis, and dyskinesia.
If left untreated, the likelihood of developing cancer and cirrhosis increases.Fish can cause diphyllobothriasis.This is cestodosis caused by the broad tapeworm.Infection with these worms occurs when eating infected fish from freshwater bodies.The most dangerous are ruffe, pike, perch, pike perch, and burbot.These are all predatory fish.The second intermediate hosts of the tapeworm are crustaceans.
These helminths live in the small intestine of humans and some animals that feed on fish with tapeworm larvae.Unlike the causative agent of opisthorchiasis, this helminth affects the intestines, causing atrophy of the mucous layer.Anemia often develops.Diphylbothriasis mainly affects adults.The risk group includes people whose family includes fishermen and lovers of dried and lightly salted fish.
Worms affecting the skin
There are helminths that affect the skin and soft tissues.This group includes Guinea worm (the causative agent of dracunculiasis).This is a nematode up to 120 cm in size. It affects subcutaneous tissue and intermuscular tissue.A person becomes infected by drinking dirty water or while swimming.Parasites penetrate the intestines and then into the subcutaneous tissue.
When the helminth becomes sexually mature, it secretes special substances that corrode the skin.An ulcerative defect forms at this site, through which the parasite removes the larvae.This happens upon contact with water.Such patients experience severe itching.Guinea worm is more common in tropical countries.The intermediate hosts are Cyclops (freshwater crustaceans).
There are worms that can independently penetrate human skin upon contact with water.These include intestinal acne.The main mechanism of infection is percutaneous.The parasite larvae damage the skin and rush into the blood.Risk factors for infection include walking on the ground with bare feet, swimming in dirty ponds, and carrying out agricultural work.
How to get rid of different types of helminths
A doctor should treat patients after conducting laboratory and instrumental studies.The antihelminthic drug is selected depending on the type of worms.
Many drugs kill and remove different types of helminths from the body.Doctors almost always prescribe broad-spectrum medications, since even after identifying parasite eggs in the stool, it is very difficult to determine their species.
If an infectious person (in the case of hymenolepidosis or enterobiasis) lives with someone else in the same apartment, then examination and treatment of these persons is required.
Each anthelmintic medicine has not only indications, but also contraindications.
Drug treatment alone is not enough.Some types of parasitic worms require surgery.In case of echinococcosis, cysts are removed.Surgery is also required if there are parasites in the heart and brain.Some helminths require sanitary and hygienic measures.
They are carried out after treatment and while taking medications.To get rid of pinworms, you need to change your underwear every day, wash and iron them, wear tight swimming trunks, wash the floors and wipe all household items.
Thus, there are a large number of different parasitic worms that live in the human body.