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Helminthiasis

worms in the human body

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 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 (X-ray, endoscopy, ultrasound, etc.) methods are used.Treatment of helminth infections depends on the type of parasite and includes specific (anthelminthic) and pathogenetic therapy.

General information

Helminth infections are helminthic infestations caused by various types of lower parasitic worms - helminths.Helminthiases have a chronic course, accompanied by depletion of the body and a decrease in its natural defenses.In the structure of helminthiases, the leading places belong to enterobiasis, ascariasis, hookworm, trichuriasis and toxocariasis.

According to official statistics, the infestation rate of the population of our country with helminthiases is 1-2%, but in some regions it reaches 10% or more.The problem of 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 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 of flukes - 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 the stages of egg, larval and mature forms.Depending on the characteristics of the development of parasitic worms and the routes of infection, helminthic diseases are divided into biohelminthiasis, geohelminthiasis and contagious (contact) helminthiases.

  1. Geohelminthsare the majority of roundworms (nematodes).The developmental stages of eggs and larvae of geohelminths take place 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.
  2. To the numberbiohelminthsbelong 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, mollusks, and insects.The causative agents of biohelminthiasis enter the human body by eating meat or fish that has not undergone sufficient heat treatment, or drinking raw water.Representatives of biohelminthiasis are diphyllobothriasis, clonorchiasis, opisthorchiasis, taeniasis, teniarinchiasis, trichinosis, fascioliasis, echinococcosis.
  3. TOcontagious helminthiasesbelong to 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 depending on 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 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:

  • Intestinal.The human intestines are parasitized by pathogens of ascariasis, enterobiasis, hookworm 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 parasitoses include filariasis, dracunculiasis, opisthorchiasis, schistosomiasis, fascioliasis, clonorchiasis, paragonimiasis, trichinosis, cystocercosis, etc.

In addition, in accordance with the localization principle, luminal (including intestinal) and tissue (skin and visceral) helminthiases are distinguished.

Symptoms of helminthiases

The clinical picture of helminthiases 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 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 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, 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 disturbances, 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.Thus, 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 to intestinal helminthiasis.With massive helminthic 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 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 ulcers of the stomach and duodenum.With trichinosis, the cardiovascular system (myocarditis, heart failure), respiratory organs (bronchitis, bronchopneumonia), and 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 echonococcosis, 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 helminthiases 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 mainly diagnosed in the chronic stage.To identify the causative agent of helminthiasis, special laboratory methods are used: microhelminthoscopic (scraping for enterobiasis), helminth-ovoscopic (examination of feces for worm eggs), helminth-larvoscopic, 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.

For intestinal helminthiasis, skin allergy tests with helminth antigens can be informative.In order 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.

worms in the intestines

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 assessed 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 medicines.

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 cyst/abscess, echinococcectomy).

Prevention

Prevention of geohelminthiases is carried out through hygienic education of the population, protecting the environment from fecal pollution, and instilling in children the rules of personal hygiene.In terms of preventing the spread of biohelminthiasis, an important role is played by 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 transmission of pathogens in organized, mainly children's, groups.It is advisable to carry out seasonal drug prevention of helminthiasis in families (for example, albendazole), regular parasitological examination of children and risk groups.