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Helminthiasis

worms in the human body

Helminthiasis– helminthic diseases caused by helminths – round and flat parasitic worms, less often ringed and with a spiny head.Helminthiases are characterized by a chronic course and systemic effects on the body with the development of abdominal, allergic, anemic syndromes and chronic toxicosis;damage to the lungs, liver, biliary tract, brain and organ of vision.In the diagnosis of helminth infections, laboratory (helminth-ovoscopic, helminth-larvoscopic, serological) and instrumental methods (radiography, endoscopy, ultrasound, etc.) are used.Treatment of helminth infections depends on the type of parasite and includes specific (anthelminthic) and pathogenetic therapy.

General information

Helminth infections are helminth infestations caused by various types of lower parasitic worms - helminths.Helminthiasis have a chronic course, accompanied by exhaustion of the body and a decrease in 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 helminthiasis infestation in the population of our country is 1-2%, but in some regions it reaches 10% or 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 of helminthiasis are known in humans;The most common are about 50 species.Parasitic helminths of the human body are mainly represented by nematodes (class Nematoda) and flatworms (class of trematodes - Trematoda and of tapeworms - Cestoidea);Less commonly, human infections occur with annelids (Annelida) and acanthocephala (Acanthocephala).Representatives of roundworms include pinworms, roundworms, trichinella, whipworms;tapeworms - bovine, porcine and dwarf tapeworms, echinococci, broad tapeworms;flukes - 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 routes of infection, helminthic diseases are divided into biohelminthiasis, geohelminthiasis and contagious (contact) helminthiasis.

  1. Geohelminthsare most roundworms (roundworms).The developmental stages of geohelminth eggs and larvae take place in the soil under certain temperature and humidity conditions.Geohelminthiasis infection occurs through lack of personal hygiene, consumption of water, fruit, vegetables contaminated by parasites or contact with soil contaminated by feces.Geohelminthiases include helminthic diseases such as ascariasis, hookworm disease, trichuriasis, strongyloidosis.
  2. To the numberbiohelminthesbelong to trematodes (trematodes) and tapeworms (cestodes), as well as some types of nematodes.To reach the invasive stage they require the change of 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, taeniasis, teniarrhiasis, trichinosis, fascioliasis, echinococcosis.
  3. Kcontagious helminthiasisbelong to invasions that are transmitted from person to person through personal contact, through sharing toiletries, dishes, underwear or through self-infection.These are enterobiasis, hymenolepiasis, strongyloidosis, cysticercosis.

Classification

Helminth infections are classified according to the biological characteristics of helminths, their mode of existence in the external environment, routes of infection and habitat in the human body.Taking into account the biological characteristics of pathogens, the following are distinguished:

  • nematodes(ascariasis, enterobiasis, trichuriasis, hookworm, necatoriasis, etc.)
  • cestodiasis(taeniasis, cysticercosis, hymenolepiasis, teniarrhiasis, echinococcosis)
  • trematodes(opisthorchiasis, clonorchiasis, schistosomiasis, fascioliasis).

According to the mode of existence of parasitic worms in the environment, geohelminthiasis, biohelminthiasis and contact helminthiasis are distinguished.Helminthiasis infection can occur through food, water, or percutaneous routes.Depending on the localization of pathogens in the human body, helminth infections are divided into:

  • Intestinal.The human intestine is parasitized by pathogens of ascariasis, enterobiasis, hookworm, tricuriasis, strongyloidosis, trichostrongyloidosis, diphyllobothriasis, taeniasis, taenirahincosis, 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, cystocercosis, etc.

Furthermore, according to the principle of localization, luminal (including intestinal) and tissue (skin and visceral) helminthiasis are distinguished.

Symptoms of helminthiasis

The clinical picture of helminthiasis is very varied and consists of the general reaction of the immune system in response to the invasion of parasites and organ-specific lesions.During helminthiasis, 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 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 syndrome (dyspepsia, abdominal pain), pulmonary syndrome (dry cough, bronchospasm, shortness of breath), hepatolienal syndrome (enlarged liver and spleen), asthenovegetative syndrome (apathy, fatigue, sleep disturbances, irritability) often develop.

Chronic phase

In the chronic phase of helminthiasis, organ-specific lesions predominate, caused mainly by mechanical trauma at the site of helminthic parasitism.Therefore, the determining factors in the course of intestinal helminthiasis are dyspeptic disorders and abdominal pain.Violation 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 helminth infestation, rectal prolapse, 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 case of migration of pinworms during enterobiasis, the development of persistent vaginitis, endometritis and salpingitis is possible.

The chronic stage of strongyloidosis occurs with the formation of ulcers of the stomach and duodenum.With trichinosis, the cardiovascular system (myocarditis, heart failure), the respiratory organs (bronchitis, bronchopneumonia) and the central nervous system (meningoencephalitis, encephalomyelitis) can be affected.Due to the invasion of the lymphatic vessels by filariasis, filariasis often develops lymphangitis, lymphedema of the extremities with swelling of the mammary glands and genitals.With econococcosis, cysts of the liver and lungs occur, and when 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 vaccination and revaccination decreases, as a result of which the necessary protective level of immunity is not achieved.In the presence of concomitant diseases, helminthiases modify and aggravate their course.The outcome of helminthiasis can be recovery (with natural death or expulsion of the helminth) or residual phenomena, often with disabling consequences.

Diagnostics

Based on clinical and epidemiological data, helminthiases are diagnosed mainly in the chronic phase.To identify the causative agent of helminthiasis, special laboratory methods are used: microhelminthoscopic (scraping for enterobiasis), helminth-ovoscopic (fecal examination for worm eggs), helminth-larvoscopic, serological (ELISA, RIF, RSK, RNGA), histological coprology.Test material for detecting eggs, larvae or fragments of mature helminths can be feces, vomit, duodenal contents, sputum, urine, blood, skin biopsies, etc.

For intestinal helminthiasis, allergy skin tests with helminth antigens may be informative.To identify and evaluate 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.

worms in the intestine

Treatment of helminthiasis

A holistic approach to the treatment of helminth infections consists of etiotropic and syndromic therapy.Specific treatment involves the prescription of anthelminthic 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
  • antitrematode
  • 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 (surgery for liver cysts/abscess, echinococcectomy).

Prevention

Prevention of geohelminthiasis is carried out through hygiene education of the population, protecting the environment from fecal pollution and instilling the rules of personal hygiene in children.In terms of preventing the spread of biohelminthiasis, an important role is played by deworming pets, veterinary and health control of 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 transmission of pathogens in organized groups, mainly children.It is recommended to carry out seasonal pharmacological prevention of helminthiasis in families (for example, albendazole), regular parasitological examination of children and risk groups.