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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.Helminthiasis is 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, bile ducts, brain and organs of vision.When diagnosing 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 (anthelmintic) and pathogenetic therapy.

General information

Helminth infections are helminth infestations caused by several types of lower parasitic worms - helminths.Helminthiasis has a chronic course, accompanied by exhaustion of the organism and a decrease in its natural defenses.In the structure of helminthiasis, the main sites belong to enterobiasis, ascariasis, hookworm, trichuriasis and toxocariasis.

According to official statistics, the rate of infestation of our country's population with helminthiasis is 1-2%, but in some regions it reaches 10% or more.The problem of increasing the incidence of helminthiasis is relevant not only for infectious diseases, but also for pediatrics, therapy, surgery, gastroenterology, dermatology, allergology, urology and other practical areas of medicine.

Causes of helminthiasis

To date, more than 250 helminthiasis pathogens in humans are known;The most common of them are about 50 species.Helminths that parasitize the human body are mainly represented by roundworms (class Nematoda) and flatworms (class of worms - 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, porcine and dwarf tapeworms, echinococci, broad tapeworm;worms - cat and liver flukes.

The life cycle of helminths includes the stages of egg, larva and mature forms.Depending on the developmental characteristics of parasitic worms and the routes of infection, helminthiasis is divided into biohelminthiasis, geohelminthiasis and contagious (contact) helminthiasis.

  1. Geohelminthsare the majority of roundworms (nematodes).The developmental stages of geohelminth eggs and larvae occur in the soil under certain temperature and humidity conditions.Infection with geohelminthiasis occurs due to lack of 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, trichuriasis, and strongyloidiasis.
  2. For the numberbiohelminthsbelong to worms (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 through eating meat or fish that has not undergone sufficient heat treatment or through drinking raw water.Representatives of biohelminthiasis are diphyllobothriasis, clonorchiasis, opisthorchiasis, taeniasis, teniarinchiasis, trichinosis, fascioliasis, echinococcosis.
  3. Kcontagious helminthiasisbelong to invasions that are transmitted from person to person through personal contact, through sharing personal hygiene products, dishes, underwear or through self-infection.These are enterobiasis, hymenolepiasis, strongyloidiasis, 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, 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.Helminthiasis infection can occur through food, water or percutaneous routes.Depending on the location of pathogens in the human body, helminth infections are divided into:

  • Intestinal.The human intestines are parasitized by pathogens of ascariasis, enterobiasis, hookworm, trichuriasis, strongyloidiasis, trichostrongyloidiasis, diphyllobothriasis, taeniasis, teniarincosis, hymenolepiasis, etc.
  • Extraintestinal.Extraintestinal helminths can live in the liver, gallbladder, blood vessels and subcutaneous tissue.Extraintestinal parasites include filariasis, dracunculiasis, opisthorchiasis, schistosomiasis, fascioliasis, clonorchiasis, paragonimiasis, trichinosis, cystocerciasis, etc.

Also, according to the principle of localization, luminal (including intestinal) and tissue (cutaneous and visceral) helminthiases 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 specific organ injuries.During helminthiasis, acute or initial 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 present with fever, rash, muscle pain and lymphadenopathy.Abdominal syndrome (dyspepsia, abdominal pain), pulmonary syndrome (dry cough, bronchospasm, shortness of breath), hepatolienal syndrome (enlargement of the liver and spleen), asthenovegetative syndrome (apathy, fatigue, sleep disturbances, irritability) often develop.

Chronic phase

In the chronic phase of helminthiasis, specific organ lesions predominate, mainly caused by mechanical trauma at the site of helminthic 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 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 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 in the stomach and duodenum.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 vessels by filariasis, filariasis often develops lymphangitis, lymphedema of the extremities with swelling of the mammary and genital glands.With econococcosis, cysts occur in the liver and lungs, 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 worsen their course.The outcome of helminthiasis can be recovery (with natural death or expulsion of the helminth) or residual phenomena, often with disabling consequences.

Diagnosis

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

For intestinal helminthiases, skin allergy tests with helminth antigens can be informative.To identify and assess the severity of specific organ lesions, instrumental diagnostics are widely used: ultrasound of the liver, pancreas, FGDS, colonoscopy, endoscopic biopsy, radiography and computed tomography of internal organs, liver scintigraphy.

worms in the intestines

Helminthiasis treatment

A holistic approach to the treatment of helminthic infections consists of etiotropic and syndromic therapy.Specific treatment involves prescribing anthelmintic medications, taking into account the type of helminth and the stage of invasion.The effectiveness of deworming is assessed based on the results of repeated parasitological examinations.For etiotropic therapy of helminthiasis, the following groups of drugs are used:

  • antinematode
  • anticestodiasis
  • anti-trematode
  • broad-spectrum medications.

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 method of treating 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 personal hygiene rules in children.In preventing the spread of biohelminthiasis, an important role is played by deworming domestic animals, veterinary and sanitary control over the sale of meat products, and careful heat treatment of meat and fish.In preventing contact helminthiasis, the main importance is to break the pathogen transmission mechanism into organized groups, mainly children.It is advisable to carry out seasonal drug prevention of helminthiasis in families (for example, albendazole), regular parasitological examinations of children and risk groups.