Helminthiasis– Helminthic diseases caused by helminths – round and flat, less often ringed and spiny-headed parasitic worms.Helminthiases are characterized by a chronic course and systemic impact on the body with the development of abdominal, allergic, anemic syndromes and chronic toxicosis;Damage to the lungs, liver, bile ducts, brain and organ of vision.In the diagnosis of helminth infections, laboratory methods (worm ovoscopy, helminth larvoscopy, serology) and instrumental methods (X-ray, endoscopy, ultrasound, etc.) are used.Treatment of helminthic infections depends on the type of parasite and includes specific (anthelmintic) and pathogenetic therapy.
General information
Helminth infections are helminthic infestations caused by various types of lower parasitic worms - helminths.Helminthiases have a chronic course, which is accompanied by exhaustion of the body and a decrease in its natural defenses.In the structure of helminthiasis, enterobiasis, ascariasis, hookworm, trichuriasis and toxocariasis occupy the top places.
According to official statistics, the infection rate of the population of our country with helminthiasis is 1-2%, but in some regions it reaches 10% and more.The problem of the increasing incidence of helminthiasis is relevant not only for infectious diseases, but also for pediatrics, therapy, surgery, gastroenterology, dermatology, allergology, urology and other practical medical areas.
Causes of helminthiasis
To date, more than 250 pathogens that cause helminthiasis in humans are known;The most common of these are about 50 species.Helminths parasitizing the human body are mainly represented by roundworms (class Nematoda) and flatworms (class of flukes - Trematoda and tapeworms - Cestoidea);Infections with annelid worms (Annelida) and acanthocephalic worms (Acanthocephala) occur less frequently in humans.Representatives of roundworms include pinworms, roundworms, trichinae, whipworms;Tapeworms – bovine, porcine and dwarf tapeworms, echinococci, broad tapeworm;Leeches – cat and liver flukes.
The life cycle of helminths includes the egg, larval and mature stages.Depending on the characteristics of the development of parasitic worms and the routes 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 take place in the soil under certain temperature and moisture conditions.Infection with geohelminthiasis occurs through poor personal hygiene, consumption of water, fruits and vegetables contaminated with parasites, or through contact with soil contaminated with feces.Geohelminthiases include helminthic diseases such as ascariasis, hookworm disease, trichuriasis and strongyloidiasis.
- To the numberBiohelminthsbelong to the leeches (trematodes) and tapeworms (cestodes) as well as some types of nematodes.To reach the invasive stage, they must change one or two intermediate hosts, which can be fish, crustaceans, molluscs and insects.The pathogens of biohelminthiasis enter the human body through consumption of insufficiently heat-treated meat or fish or through drinking raw water.Representatives of biohelminthiasis are diphyllobothriasis, clonorchiasis, opisthorchiasis, taeniasis, teniarinchiasis, trichinosis, fascioliasis, echinococcosis.
- Kinfectious helminthiasisare among the invasions that are transmitted from person to person through personal contact, through shared toiletries, dishes, underwear, or through self-infection.These are enterobiasis, hymenolepiasis, strongyloidiasis, cysticercosis.
Classification
Helminth infections are classified according to the biological characteristics of the helminths, their mode of existence in the external environment, the routes of infection and their habitat in the human body.Taking into account the biological properties of pathogens, the following are distinguished:
- Nematodes(Ascariasis, enterobiasis, trichuriasis, hookworm disease, necatoriasis, etc.)
- Cestodiases(taeniasis, cysticercosis, hymenolepiasis, teniarinchiasis, 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:
- Colon.The human intestine is parasitized by pathogens of ascariasis, enterobiasis, hookworm disease, trichuriasis, strongyloidiasis, trichostrongyloidiasis, diphyllobothriasis, taeniasis, taeniarynchosis, hymenolepiasis, etc.
- Extraintestinal.Extraintestinal helminths can live in the liver, gallbladder, blood vessels and subcutaneous tissue.Extraintestinal parasitoses include filariasis, dracunculiasis, opisthorchiasis, schistosomiasis, fascioliasis, clonorchiasis, paragonimiasis, trichinosis, cystocerciasis, etc.
In addition, according to the principle of localization, luminal (including intestinal) and tissue (skin and visceral) helminthiases are distinguished.
Symptoms of helminthiasis
The clinical picture of helminthiases is very diverse and consists of the general reaction of the immune system in response to parasite invasion and organ-specific lesions.In helminthiases, 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, nutritional and vitamin deficiencies, and reduced immunological competence.
Acute phase
In the acute phase of helminthiasis, the main manifestations are caused by the toxic-allergic effect of parasitic worms on the body.Patients experience fever, rash, myalgia, and lymphadenopathy.Abdominal syndrome (dyspepsia, abdominal pain), pulmonary syndrome (dry cough, bronchospasm, shortness of breath), hepatolienal syndrome (enlargement of the liver and spleen) and asthenovegetative syndrome (apathy, fatigue, sleep disorders, irritability) often develop.
Chronic phase
In the chronic phase of helminthiasis, organ-specific lesions predominate, caused mainly by mechanical trauma at the site of helminth parasitism.Therefore, the determining factors in the course of intestinal helminthiasis are dyspeptic disorders and abdominal pain.Violation of the absorption processes in the intestine is accompanied by polyhypovitaminosis and progressive loss of body weight.Iron deficiency anemia is a common symptom of intestinal helminthiasis.With massive helminthic infestation, rectal prolapse, development of hemorrhagic colitis and intestinal obstruction are possible.
In the chronic phase of helminthiasis, which is accompanied by primary damage to the hepatobiliary system, obstructive jaundice, hepatitis, cholecystitis, cholangitis and pancreatitis may occur.When migrating pinworms during enterobiasis, the development of persistent vaginitis, endometritis and salpingitis is possible.
The chronic stage of strongyloidiasis occurs with the formation of gastric and duodenal ulcers.With trichinosis, the cardiovascular system (myocarditis, heart failure), the respiratory system (bronchitis, bronchopneumonia) and the central nervous system (meningoencephalitis, encephalomyelitis) can be affected.Due to the invasion of lymphatic vessels by filariasis, lymphangitis, lymphedema of the extremities with swelling of the mammary glands and genitals, often develops in filariasis.With echonococcosis, liver and lung cysts occur, and if they suppurate, complications in the form of purulent peritonitis or pleurisy are possible.
Against the background of helminthiasis in children and adults, the effectiveness of preventive vaccinations and revaccinations decreases, as a result of which the necessary level of protection of immunity is not achieved.In the presence of concomitant diseases, helminthiases change and worsen their course.The outcome of helminthiasis can be recovery (with natural death or expulsion of the helminth) or a residual phenomenon, often with disabling consequences.
diagnosis
Based on clinical and epidemiological data, helminthiases are diagnosed mainly in the chronic stage.To identify the causative agent of helminthiasis, special laboratory methods are used: microhelminthoscopy (scraping for enterobiasis), helminth ovoscopy (examination of feces for worm eggs), helminth larvoscopy, serological (ELISA, RIF, RSK, RNGA), histological coprology.The test material for detecting eggs, larvae or fragments of mature helminths can be feces, vomit, duodenal contents, sputum, urine, blood, skin biopsies, etc.
In intestinal helminthiasis, skin allergy tests with helminth antigens can be informative.To detect and assess the severity of organ-specific lesions, instrumental diagnostics are often 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 includes the prescription of anthelmintics, taking into account the type of helminth and the stage of invasion.The effectiveness of deworming is assessed based on the results of a repeated parasitological examination.The following groups of drugs are used for etiotropic therapy of helminthiasis:
- Antinematode
- Anticestodiasis
- Anti-trematode
- Broad-spectrum medications.
With intestinal helminthiasis, antibacterial drugs, enterosorbents, enzymes, probiotics, etc. are added to the main treatment.Symptomatic therapy of helminthiasis may include the prescription of antihistamines, intravenous infusions, vitamins, cardiac glycosides, NSAIDs and glucocorticoids.In echinococcosis, the main method of treatment for patients is surgery (surgery for liver cysts/abscesses, echinococcectomy).
Prevention
Prevention of geohelminthiasis is carried out through hygiene education of the population, protecting the environment from fecal pollution and teaching children the rules of personal hygiene.In terms of preventing the spread of biohelminthiasis, deworming of pets, veterinary and hygienic control of the sale of meat products, and careful heat treatment of meat and fish play an important role.The prevention of contact helminthiasis is primarily about interrupting the mechanism of transmission of pathogens in organized, mainly children's, groups.It is advisable to carry out seasonal drug prevention of helminthiasis (e.g. albendazole) in families, as well as regular parasitological examination of children and risk groups.