Helminthiasis– helminthic diseases caused by helminths – round and flat, less often ringed and thorn-headed parasitic worms.Helminthiases are characterized by a chronic course and systemic effects on the body with the development of stomach, allergies, anemia syndrome, and chronic toxicosis;damage to the lungs, liver, bile ducts, brain, and organs of vision.In the diagnosis of helminth infection, laboratory (helminth-ovoscopic, helminth-larvoscopic, serological) and instrumental (X-ray, endoscopy, ultrasound, etc.) methods are used.Treatment of helminth infections depends on the type of parasite and includes specific (anthelmintic) and pathogenetic therapy.
General information
Helminth infection is a helminthic attack caused by various types of lower parasitic worms - helminths.Helminthiases have a chronic course, accompanied by a deficiency of the body and a decrease in its natural defenses.In the structure of helminthiases, the main place belongs to enterobiasis, ascariasis, hookworm, trichuriasis and toxocariasis.
According to official statistics, the infection rate of our country's population with helminthiases is 1-2%, but in some regions it reaches 10% or more.The problem of increased incidence of helminthiasis is relevant not only for infectious diseases, but also for pediatrics, therapy, surgery, gastroenterology, dermatology, allergy, urology and other practical medical fields.
Causes of helminthiasis
To date, more than 250 helminthiasis pathogens in humans are known;The most common of them are about 50 species.Helminths parasitizing the human body are mainly represented by roundworms (class Nematoda) and flatworms (class flukes - Trematoda and tapeworms - Cestoidea);Less commonly, human infection occurs with annelids (Annelida) and acanthocephala (Acanthocephala).Representatives of roundworms include pinworms, roundworms, trichinella, whipworms;tapeworms - cattle, pork and dwarf tapeworms, echinococci, broad tapeworms;worms - cat and liver lice.
The life cycle of helminths includes egg, larval and mature stages.Depending on the characteristics of the development of parasitic worms and the route of infection, helminthic diseases are divided into biohelminthiasis, geohelminthiasis and infectious (contact) helminthiases.
- Geohelminthsare the majority of roundworms (nematodes).The developmental stages of eggs and larvae of geohelminths occur in the soil under certain temperature and humidity conditions.Infection with geohelminthiasis occurs through failure to maintain personal hygiene, consumption of water, fruits, vegetables contaminated with parasites, or contact with soil contaminated with feces.Geohelminthiases include helminthic diseases such as ascariasis, hookworm disease, trichuriasis, strongyloidiasis.
- To the numberbiohelminthsbelong to flukes (trematodes) and tapeworms (cestodes), as well as some types of nematodes.To reach the invasive stage, they require changes in one or two intermediate hosts, which can be fish, crustaceans, molluscs and insects.The causative agent of biohelminthiasis enters the human body by eating meat or fish that has not undergone adequate heat treatment, or drinking raw water.Representatives of biohelminthiasis are diphyllobothriasis, clonorchiasis, opisthorchiasis, taeniasis, teniarynchiasis, trichinosis, fascioliasis, echinococcosis.
- Kinfectious helminthiasesbelongs to the invasion transmitted from person to person through personal contact, through shared toiletries, crockery, underwear or through self-infection.These are enterobiasis, hymenolepiasis, strongyloidiasis, cysticercosis.
Classification
Helminth infections are classified depending on the biological characteristics of helminths, the way they exist in the external environment, the route of infection, and the habitat in the human body.Taking into account the biological characteristics of pathogens, the following are distinguished:
- nematodes(ascariasis, enterobiasis, trichuriasis, hookworm disease, necatoriasis, etc.)
- cestodiases(taeniasis, cysticercosis, hymenolepiasis, teniarynchiasis, echinococcosis)
- trematodes(opisthorchiasis, clonorchiasis, schistosomiasis, fascioliasis).
Based on the way parasitic worms exist 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 the pathogen in the human body, helminth infections are divided into:
- intestine.The human intestine is parasitized by pathogens of ascariasis, enterobiasis, hookworm disease, trichuriasis, strongyloidiasis, trichostrongyloidiasis, diphyllobothriasis, taeniasis, taeniarynchosis, hymenolepiasis, etc.
- outside the intestine.Extraintestinal helminths can live in the liver, gallbladder, blood vessels, and subcutaneous tissue.Extraintestinal parasites include filariasis, dracunculiasis, opisthorchiasis, schistosomiasis, fascioliasis, clonorchiasis, paragonimiasis, trichinosis, cystocercosis, etc.
In addition, according to the principle of localization, luminal (including intestinal) and tissue (skin and visceral) helminthiases are distinguished.
Symptoms of helminthiases
The clinical picture of helminthiases is very diverse and consists of a general reaction of the immune system in response to parasite invasion and organ-specific lesions.During helminthiases, an acute or initial phase (from 2-3 weeks to 2 months) and a chronic phase (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 deficiencies, and decreased immunological efficiency.
Acute phase
In the acute period of helminthiasis, the main manifestation is caused by the toxic-allergic effects of parasitic worms on the body.Patients experience fever, skin rash, muscle pain, and lymphadenopathy.Abdominal syndrome (dyspepsia, abdominal pain), pulmonary syndrome (dry cough, bronchospasm, shortness of breath), hepatolienal syndrome (enlarged liver and spleen), asthenovegetative syndrome (apathy, fatigue, sleep disturbance, irritability) often develop.
Chronic phase
In the chronic phase of helminthiasis, organ-specific lesions predominate, caused mainly by mechanical trauma to the site of helminth parasitism.Therefore, the decisive factors in the course of intestinal helminthiasis are dyspeptic disorders and abdominal pain.Violation of the absorption process in the intestine is accompanied by polyhypovitaminosis and progressive weight loss.Iron deficiency anemia is a frequent companion to intestinal helminthiasis.With a large helminthic attack, rectal prolapse, the development of hemorrhagic colitis, and intestinal obstruction are possible.
In the chronic phase of helminthiasis, which occurs with primary damage to the hepatobiliary system, obstructive jaundice, hepatitis, cholecystitis, cholangitis, and pancreatitis may occur.In the case of migration of pinworms during enterobiasis, the development of persistent vaginitis, endometritis, and salpingitis is possible.
The chronic stage 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 channels by filariasis, filariasis often causes lymphangitis, lymphedema of the legs with swelling of the mammary glands and genitals.With echonococcosis, liver and lung cysts occur, and when they suppurate, complications in the form of purulent peritonitis or pleurisy are possible.
Against the background of helminthiases in children and adults, the effectiveness of preventive vaccination and revaccination decreases, as a result of which the necessary level of immunity protection is not achieved.In the presence of concomitant diseases, helminthiases modify and worsen their course.The result of helminthiasis can be recovery (with natural death or expulsion of the helminth) or a residual phenomenon, often with disabling consequences.
Diagnostics
Based on clinical and epidemiological data, helminthiases are mostly diagnosed at the chronic stage.To identify the causative agent of helminthiasis, special laboratory methods are used: microhelminthoscopy (scraping for enterobiasis), helminth-ovoscopic (examination of feces for worm eggs), helminth-larvoscopic, serology (ELISA, RIF, RSK, RNGA), histology coprology.Test material to detect eggs, larvae or fragments of mature helminths can be feces, vomit, duodenal contents, sputum, urine, blood, skin biopsy, etc.
For intestinal helminthiasis, skin allergy testing with helminth antigens can be informative.To identify and assess the severity of organ-specific lesions, instrumental diagnostics are widely used: ultrasound of the liver, pancreas, FGDS, colonoscopy, endoscopic biopsy, radiography and CT of internal organs, liver scintigraphy.
Treatment of helminthiasis
A holistic approach to the treatment of helminth infections consists of etiotropic and syndromic therapy.Specific treatment involves 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 repeated parasitological examinations.For etiotropic therapy of helminthiasis, the following groups of drugs are used:
- antinematode
- anticestodiasis
- anti-trematodes
- broad spectrum medicine.
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 (cyst/liver abscess surgery, echinococcectomy).
Prevention
Prevention of geohelminthiases is carried out through hygiene education of the population, protecting the environment from faecal pollution, and applying personal hygiene rules to children.In terms of preventing the spread of biohelminthiasis, an important role is played by the deworming of domestic animals, veterinary and sanitary control over the sale of meat products, and careful heat treatment of meat and fish.In the prevention of contact helminthiasis, the main importance is to break the mechanism of pathogen transmission in organized groups, especially children.It is advisable to carry out seasonal drug prevention against helminthiasis in the family (for example, albendazole), regular parasitological examination of children and risk groups.