Helminthoses- helminthic diseases caused by helminths - parasitic worms with round and flat, less ringed and thorny heads.Helminthosis is characterized by a chronic course and systemic effects on the body with the development of abdominal, allergic, anemia syndromes and chronic toxicoses;damage to the lungs, liver, bile ducts, brain and vision.In the diagnosis of helminth infections, 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 consists of specific (anthelminthic) and pathogenetic therapy.
General information
Helminth infections are helminthic infestations caused by various types of lower parasitic worms - helminths.Helminths have a chronic course, accompanied by exhaustion of the body and a decrease in natural defenses.In the structure of helminthosis, the leading places are occupied by enterobiosis, ascariasis, ankiliosis, trichuriosis and toxocarosis.
According to official statistics, although the level of infection with helminths in our country is 1-2%, in some regions this indicator is 10% or more.The problem of increasing helminthosis is relevant not only for infectious diseases, but also for pediatrics, therapy, surgery, gastroenterology, dermatology, allergology, urology and other practical medical fields.
Causes of helminthiasis
To date, more than 250 helminthic pathogens are known in humans;The most common of them are about 50 species.Helminths parasitizing the human body are mainly represented by roundworms (Nematoda class) and flatworms (flukes class - Trematoda and tapeworms - Cestoidea);Less commonly, human infections occur with annelids (Annelida) and acanthocephala (Acanthocephala).Representatives of roundworms include pinworms, roundworms, trichinella, whipworms;tapeworms - bovine, pork and dwarf tapeworms, echinococci, broad tapeworm;flukes - cat and liver flukes.
The life cycle of helminths includes egg, larva and adult stages.Depending on the development characteristics of parasitic worms and ways of infection, helminthosis diseases are divided into biohelminthosis, geohelminthosis and infectious (contact) helminthosis.
- Geohelminthsare the majority of roundworms (nematodes).Development stages of eggs and larvae of geohelminths occur in the soil under certain temperature and humidity conditions.Infection with geohelminthosis occurs as a result of non-observance of personal hygiene rules, consumption of water, fruits, vegetables contaminated with parasites or contact with soil contaminated with feces.Geohelminthoses include helminthic diseases such as ascariasis, ankylosis, trichuriasis, strongyloidosis.
- To the numberbiohelminthsflukes (trematodes) and tapeworms (cestodes), as well as some species of nematodes.To reach the invasive stage, one or two intermediate hosts, which may be fish, crustaceans, molluscs, and insects, are required.The causative agent of biohelminthosis enters the human body by eating meat or fish that has not undergone sufficient heat treatment, and by drinking raw water.Representatives of biohelminthosis are diphyllobothriasis, clonorchosis, opisthorchosis, taeniasis, teniarynchosis, trichinosis, fascioliasis, echinococcosis.
- Kinfectious helminthsrefers to infestations transmitted from person to person through personal contact, shared toiletries, utensils, underwear, or self-infection.These are enterobiosis, hymenolepiasis, strongyloidosis, cysticercosis.
Classification
Helminth infections are classified depending on the biological characteristics of helminths, the way they live in the external environment, the ways of infection and the place of residence in the human body.Taking into account the biological characteristics of pathogens, the following are distinguished:
- nematodes(ascaridosis, enterobiosis, trichuriasis, garkiliosis disease, nekatorosis, etc.)
- cestodiases(teniasis, cysticercosis, hymenolepiasis, teniarynchosis, echinococcosis)
- trematodes(opisthorchosis, clonorchiasis, schistosomiasis, fascioliasis).
Depending on the way parasitic worms live in the environment, geohelminthoses, biohelminthoses and contact helminthoses are distinguished.Helminth infection can occur through food, water or percutaneously.Depending on the localization of pathogens in the human body, helminth infections are divided into:
- gut.Human intestines are affected by ascariasis, enterobiosis, garkiliosis, trichuriasis, strongyloidosis, trichostrongyloidosis, diphyllobothriasis, taeniasis, taeniarhynchosis, hymenolepiasis, etc.parasitised by pathogens.
- Extraintestinal.Extraintestinal helminths can live in the liver, gall bladder, blood vessels and subcutaneous tissue.Extraintestinal parasitosis includes filariasis, dracunculosis, opisthorchosis, schistosomiasis, fascioliasis, clonorchosis, paragonimiasis, trichinosis, cystocercosis, etc.
In addition, according to the principle of localization, luminal (including intestinal) and tissue (skin and visceral) helminthoses are distinguished.
Symptoms of helminthiasis
The clinical picture of helminthiasis is very diverse and consists of a general reaction of the immune system in response to the invasion of parasites and organ-specific lesions.During helminthosis, acute or early phases (from 2-3 weeks to 2 months) and chronic phases (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, lack of nutrients and vitamins, and a decrease in immunological competence.
Acute phase
In the acute period of helminthosis, the main manifestations are caused by the toxic-allergic effect of parasitic worms on the body.Patients present with 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 disorders, irritability) often develop.
Chronic stage
In the chronic stage of helminthosis, organ-specific lesions predominate, mainly caused by mechanical damage to the site of helminth parasitism.Thus, the determining factors in the course of intestinal helminthosis are dyspeptic disorders and abdominal pain.Disruption of absorption processes in the intestine is accompanied by polyhypovitaminosis and progressive loss of body weight.Iron deficiency anemia is a frequent companion of intestinal helminthiasis.With massive helminthic infestation, rectal prolapse, development of hemorrhagic colitis and intestinal obstruction are possible.
Obstructive jaundice, hepatitis, cholecystitis, cholangitis, pancreatitis can occur in the chronic stage of helminthosis, which occurs with primary damage to the hepatobiliary system.In the case of migration of pinworms during enterobiosis, the development of persistent vaginitis, endometritis and salpingitis is possible.
The chronic stage of strongyloidosis occurs with the formation of gastric and duodenal ulcers.Trichinosis can affect the cardiovascular system (myocarditis, heart failure), respiratory organs (bronchitis, bronchopneumonia) and the central nervous system (meningoencephalitis, encephalomyelitis).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 exonococcosis, liver and lung cysts are formed, and when they are purulent, 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 achieved.In the presence of accompanying diseases, helminthosis changes and aggravates their course.The result of helminthosis can be recovery (with natural death or expulsion of the helminth) or residual events, often leading to disability.
Diagnostics
According to clinical and epidemiological data, helminthosis is mainly diagnosed in the chronic stage.To determine the causative agent of helminthosis, special laboratory methods are used: microhelminthoscopy (scraping for enterobiosis), helminth-ovoscopic (examination of feces for worm eggs), helminth-larvoscopic, serological (ELISA, RIF, RSK, RNGA), histological coprology.To detect eggs, larvae or fragments of adult helminths, the test material is feces, vomit, duodenal contents, sputum, urine, blood, skin biopsies, etc.
Skin allergy tests with helminth antigens can be informative for intestinal helminthiasis.Instrumental diagnostics are widely used to determine and evaluate the severity of organ-specific lesions: ultrasound of the liver, pancreas, FGDS, colonoscopy, endoscopic biopsy, radiography of internal organs and CT, liver scintigraphy.
Treatment of helminthiasis
A unified approach to the treatment of helminth infections consists of etiotropic and syndromic therapy.Special treatment involves the appointment of anthelmintic drugs, taking into account the type of helminths and the stage of invasion.The effectiveness of deworming is evaluated based on the results of repeated parasitological examination.The following drug groups are used for etiotropic treatment of helminthosis:
- antinematode
- anticestodiasis
- anti-trematod
- broad spectrum drugs.
The main treatment for intestinal helminthiasis includes antibacterial drugs, enterosorbents, enzymes, probiotics, etc.Symptomatic therapy for helminthosis may include the appointment of antihistamines, intravenous infusions, vitamins, cardiac glycosides, NSAIDs, and glucocorticoids.The main treatment for patients with echinococcosis is surgery (liver cyst/abscess surgery, echinococcectomy).
Prevention
Prevention of geohelminthiasis is carried out through hygienic education of the population, protection of the environment from faecal contamination, instilling personal hygiene rules in children.In terms of preventing the spread of biohelminthosis, deworming of domestic animals, veterinary-sanitary control of the sale of meat products, and careful heat treatment of meat and fish play an important role.The main importance in the prevention of contact helminthiasis is to disrupt the transmission mechanism of pathogens in organized, mainly children's groups.Seasonal drug prevention of helminthosis (for example, albendazole) in families, regular parasitological examination of children and risk groups is appropriate.