Helminthiasis– helminthic diseases caused by helminths – round and flat parasitic worms, less often ringed and spiny.Helminthiasis is characterized by a chronic course and systemic effects on the body with the development of abdominal, allergic, anemic and chronic toxicosis syndromes;damage to the lungs, liver, biliary tract, brain and organ of vision.In the diagnosis of helminthic infections, laboratory (helminto-ovoscopic, helminto-larvoscopic, serological) and instrumental (x-ray, endoscopy, ultrasound, etc.) methods are used.Treatment of helminthic infections depends on the type of parasite and includes specific (anthelmintic) and pathogenetic therapy.
General information
Helminthic infections are helminthic infections caused by various types of lower parasitic worms - helminths.Helminthiasis has a chronic course, accompanied by depletion of the body and reduction of its natural defenses.In the structure of helminthiasis, the main places belong to enterobiasis, ascariasis, hookworm, trichuriasis and toxocariasis.
According to official statistics, the rate of infection of the population of our country with helminthiasis is 1-2%, but in some regions it reaches 10% or more.The problem of increasing the incidence of helminthiasis is important not only for infectious diseases, but also for pediatrics, therapy, surgery, gastroenterology, dermatology, allergology, urology and other fields of medical practice.
Causes of helminthiasis
To date, more than 250 pathogens of helminthiasis in humans are known;The most common of them are about 50 species.Helminths that parasitize the human body are mainly represented by roundworms (class Nematoda) and flatworms (class fluxes - Trematoda and tapeworms - Cestoidea);Less commonly, human infections occur with annelids (Annelida) and acanthocephala (Acanthocephala).Representatives of roundworms include roundworms, roundworms, trichinella, whipworms;stripes - bovine, pig and dwarf stripe, echinococcus, broad stripe;Flukes - cat and liver flukes.
The life cycle of helminths includes egg, larval and mature stages.Depending on the characteristics of the development of parasitic worms and routes of infection, helminthic diseases are divided into biohelminthiasis, geohelminthiasis and contagious (contact) helminthiasis.
- Geohelminthsare most roundworms (nematodes).Egg and larval development stages of geohelminths develop in the soil under certain conditions of temperature and humidity.Infection with geohelminthiasis occurs through poor personal hygiene, consumption of water, fruits, vegetables contaminated with parasites or contact with soil contaminated with feces.Geohelminthiasis includes helminthic diseases such as ascariasis, needleworm disease, trichuriasis, strongyloidiasis.
- To the numberbiohelminthsthey belong to flukes (trematodes) and tapeworms (cestodes), as well as some types of nematodes.To reach the invasive stage, they need a change in one or two intermediate hosts, which can be fish, crustaceans, molluscs and insects.The causative agents of biohelminthiasis enter the human body by eating meat or fish that has not undergone sufficient heat treatment, or by drinking raw water.Representatives of biohelminthiasis are diphyllobothriasis, clonorchiasis, opisthorchiasis, taenia, teniarynchiasis, trichinosis, fascioliasis, echinococcosis.
- Kcontagious helminthiasesbelong to infections that are transmitted from person to person through personal contact, through shared toilets, dishes, underwear or through self-infection.These are enterobiasis, hymenolepiasis, strongyloidiasis, cysticercosis.
Distribution
Helminth infections are classified depending on the biological characteristics of helminths, their mode of existence in the external environment, routes of infection and habitat in the human body.Considering the biological characteristics of pathogens, the following are distinguished:
- nematodes(ascariasis, enterobiasis, trichuriasis, breast worm disease, nekatoriasis, etc.)
- cestodiases(taniasis, cysticercosis, hymenolepiiasis, teniarynchiasis, echinococcosis)
- trematodes(opisthorchiasis, clonorchiasis, schistosomiasis, fascioliasis).
Based on the mode of existence of parasitic worms in the environment, geohelminthiasis, biohelminthiasis and contact helminthiasis are distinguished.Infection with helminthiasis can occur through food, water or percutaneous routes.Depending on the localization of pathogens in the human body, helminth infections are divided into:
- Intestinal.Human intestines are parasitized by pathogens of ascariasis, enterobiasis, needleworm disease, trichuriasis, strongyloidiasis, trichostrongyloidiasis, diphyllobothriasis, taeniasis, taeniarynchosis, hymenolepiasis, etc.
- Extraintestinal.Extraintestinal helminths can live in the liver, gall bladder, blood vessels and subcutaneous tissue.Extraintestinal parasites include filariasis, dracunculiasis, opisthorchiasis, schistosomiasis, fascioliasis, clonorchiasis, paragonimiasis, trichinosis, cystocercosis, etc.
In addition, in accordance with the principle of localization, luminal (including intestines) and tissue (skin and visceral) helminthiases are distinguished.
Symptoms of helminthiasis
The clinical framework of helminthiasis is very diverse and consists of the general reaction of the immune system in response to the invasion of parasites and lesions of specific organs.During helminthiasis, acute or early stages (from 2-3 weeks to 2 months) and chronic stages (up to several years) are distinguished.The main pathological effects of helminths on the human body include toxic-allergic reactions, mechanical damage to organs and tissues, nutritional and vitamin deficiency, and decreased immunological competence.
Acute phase
In the acute period of helminthiasis, the main manifestations are caused by the toxic-allergic effect of parasitic worms on the body.Patients experience fever, rash, muscle pain, and lymphadenopathy.Abdominal syndromes (indigestion, abdominal pain), pulmonary syndromes (dry cough, bronchospasm, shortness of breath), hepatolienal syndromes (enlarged liver and spleen), asthenovegetative syndromes (apathy, fatigue, sleep disturbances, irritability) often develop.
Chronic phase
In the chronic phase of helminthiasis, organ-specific damage mainly caused by mechanical trauma in the place of helminthic parasitism predominates.Thus, the determining factors in the course of intestinal helminthiasis are dyspeptic disorders and abdominal pain.Violation of intestinal absorption processes is associated with polyhypovitaminosis and progressive loss of body weight.Iron deficiency anemia is a frequent companion of intestinal helminthiasis.With massive helminthic infection, rectal prolapse, development of hemorrhagic colitis and intestinal obstruction are possible.
In the chronic phase of helminthiasis, which appears with primary damage to the hepatobiliary system, obstructive jaundice, hepatitis, cholecystitis, cholangitis and pancreatitis may appear.In the case of the migration of worms during enterobiasis, the development of persistent vaginitis, endometritis and salpingitis is possible.
The chronic phase of strongyloidiasis occurs with the formation of stomach and duodenal ulcers.With trichinosis, the cardiovascular system (myocarditis, heart failure), respiratory organs (bronchitis, bronchopneumonia) and the central nervous system (meningoencephalitis, encephalomyelitis) can be affected.Due to the invasion of lymphatic vessels by filariasis, filariasis often develops lymphangitis, lymphedema of the extremities with swelling of the mammary glands and genitals.With echinococcosis, liver and lung cysts occur, and when they suffocate, complications in the form of purulent peritonitis or pleurisy are possible.
Against the background of helminthiasis in children and adults, the effectiveness of preventive vaccination and revaccination decreases, as a result of which the necessary protective level of immunity is not reached.In the presence of accompanying diseases, helminthiases modify and worsen their progress.The result of helminthiasis can be recovery (with natural death or expulsion of the helminth) or residual phenomena, often with disabling consequences.
Diagnosing
Based on clinical and epidemiological data, helminthiasis is mainly diagnosed in the chronic phase.To identify the causative agent of helminthiasis, special laboratory methods are used: microhelmintoscopic (scraping for enterobiasis), helminto-ovoscopic (examination of feces for worm eggs), helminth-larvoscopic, serological (ELISA, RIF, RSK, RNGA), histological coprology.Test material for the detection of eggs, larvae or fragments of mature helminths can be feces, vomit, duodenal contents, saliva, urine, blood, skin biopsies, etc.
For intestinal helminthiasis, skin allergy tests with helminth antigens can be informative.To identify and assess the severity of specific organ lesions, instrumental diagnostics are widely used: ultrasound of the liver, pancreas, FGDS, colonoscopy, endoscopic biopsy, radiography and CT of internal organs, scintigraphy of the liver.
Treatment of helminthiasis
A holistic approach to the treatment of helminth infections consists of etiotropic and syndromic therapy.Specific treatment includes the prescription of anthelmintic drugs, taking into account the type of helminth and the stage of invasion.The effectiveness of deworming is evaluated based on the results of a repeated parasitological examination.For etiotropic therapy of helminthiasis, the following groups of drugs are used:
- antinematode
- anticestodiasis
- anti-trematode
- broad spectrum drugs.
For intestinal helminthiasis, antibacterial drugs, enterosorbents, enzymes, probiotics, etc. are added to the main treatment.Symptomatic therapy for helminthiasis may include the prescription of antihistamines, intravenous infusions, vitamins, cardiac glycosides, NSAIDs and glucocorticoids.For echinococcosis, the main treatment method for patients is surgery (liver cyst/abscess surgery, echinococcectomy).
Preventing
The prevention of geohelminthiasis is achieved through hygienic education of the population, protection of the environment from fecal pollution and introduction of personal hygiene rules to children.In terms of preventing the spread of biohelminthiasis, an important role is played by deworming domestic animals, veterinary and sanitary control over the sale of meat products and careful thermal treatment of meat and fish.In the prevention of contact helminthiasis, the main importance is breaking the transmission mechanism of pathogens in organized groups, mainly children.It is recommended to carry out seasonal medicinal prevention of helminthiasis in the family (for example, albendazole), regular parasitological examination of children and risk groups.