Helminthiases- helminthic diseases caused by helminths - round and flat, less often annelids 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, chronic toxicosis; damage to the lungs, liver, biliary tract, brain, organ of vision. In the diagnosis of helminthiases, laboratory (helminthoovoscopic, helmintholarvoscopic, serological) and instrumental (X-ray, endoscopy, ultrasound, etc. ) methods are used. Treatment of helminthiases depends on the type of parasite and includes specific (anthelmintic) and pathogenetic therapy.
Helminthiases 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 invasion of the population of our country by helminthiases is 1-2%, but in some regions it reaches 10% or more. The problem of the increase in the incidence of helminthiases is relevant not only for infectious diseases, but also for pediatrics, therapy, surgery, gastroenterology, dermatology, allergology, urology and other practical medical areas.
Causes of helminthiases
To date, more than 250 pathogens of helminthiases in humans are known; Of these, about 50 species are the most common. Helminths parasitizing in the human body are mainly represented by roundworms (class Nematoda) and flatworms (class of flukes - Trematoda and tapeworms - Cestoidea); less common is human infection with annelids (Annelida) and acanthocephala (Acanthocephala). Representatives of roundworms include pinworms, roundworms, trichinella, whipworm; tape - bovine, pork and dwarf tapeworm, echinococcus, wide tapeworm; flukes - cat and liver flukes.
The life cycle of helminths includes the stages of egg, larval and sexually mature forms. Depending on the characteristics of the development of parasitic worms and the ways of infection, helminthic diseases are divided into biohelminthiases, geohelminthiases and contagious (contact) helminthiases.
- Geohelminthsare the majority of roundworms (nematodes). The stages of development of eggs and larvae of geohelminths take place in the soil under certain temperature and humidity conditions. Infection with soil helminthiases occurs when personal hygiene is not observed, eating water contaminated with parasites, fruits, vegetables, or contact with soil contaminated with feces. Geohelminthiases include such helminthic diseases as ascariasis, ankylostomidosis, trichuriasis, strongyloidiasis.
- To the numberbiohelminthsbelong flukes (trematodes) and tapeworms (cestodes), as well as some types of nematodes. To reach the invasive stage, they need to change one or two intermediate hosts, which can be fish, crustaceans, mollusks, and insects. The causative agents of biohelminthiases enter the human body when eating meat or fish that has not undergone sufficient heat treatment, drinking raw water. Representatives of biohelminthiases are diphyllobothriasis, clonorchiasis, opisthorchiasis, teniasis, teniarinhoz, trichinosis, fascioliasis, echinococcosis.
- TOcontagious helminthiasesbelong to invasions transmitted from person to person through personal contact, through common toilet items, dishes, linen, or by self-infection. These are enterobiasis, hymenolepiasis, strongyloidiasis, cysticercosis.
Helminthiases are classified depending on the biological characteristics of helminths, the mode of existence in the external environment, the ways of infection, and habitat in the human body. Taking into account the biological characteristics of pathogens, there are:
- nematodes(ascariasis, enterobiasis, trichuriasis, ankylostomidosis, necatoriasis, etc. )
- cestodoses(taeniasis, cysticercosis, hymenolepiasis, teniarinhoz, echinococcosis)
- trematodoses(opisthorchiasis, clonorchiasis, schistosomiasis, fascioliasis).
According to the mode of existence of parasitic worms in the environment, geohelminthiases, biohelminthiases and contact helminthiases are distinguished. Infection with helminthiases can occur by food, water, percutaneous route. Depending on the localization of pathogens in the human body, helminthiases are divided into:
- Intestinal. The pathogens of ascariasis, enterobiasis, ankylostomidosis, trichuriasis, strongyloidiasis, trichostrongyloidiasis, diphyllobothriasis, teniasis, teniarhynchosis, hymenolepiasis, etc. parasitize in the human intestine.
- extraintestinal. Extraintestinal helminths can live in the liver, gallbladder, blood vessels, subcutaneous tissue. Extraintestinal parasitoses include filariasis, dracunculiasis, opisthorchiasis, schistosomiasis, fascioliasis, clonorchiasis, paragonimiasis, trichinosis, cystocercosis, etc.
In addition, in accordance with the localization principle, there are luminal (including intestinal) and tissue (skin and visceral) helminthiases.
Symptoms of helminthiases
The clinical picture of helminthiases is very variegated 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 (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, alimentary and vitamin deficiency, and a decrease in immunological competence.
In the acute period of helminthiasis, the main manifestations are due to the toxic-allergic effect of parasitic worms on the body. Patients have fever, skin rash, muscle pain, 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.
In the chronic phase of helminthiasis, organ-specific lesions predominate, mainly due to mechanical trauma to the site of parasitism of the helminth. So, dyspeptic disorders and abdominal pains are decisive for the course of intestinal helminthiases. Violation of absorption processes in the intestine is accompanied by polyhypovitaminosis, progressive weight loss. Iron deficiency anemia is a frequent companion of intestinal helminthiasis. With massive helminthic invasion, prolapse of the rectum, the development of hemorrhagic colitis, and intestinal obstruction are possible.
In the chronic phase of helminthiases occurring with a predominant lesion of the hepatobiliary system, obstructive jaundice, hepatitis, cholecystitis, cholangitis, and pancreatitis may occur. In the case of pinworm migration during enterobiasis, persistent vaginitis, endometritis, and salpingitis may develop.
The chronic stage of strongyloidiasis proceeds with the formation of stomach and duodenal ulcers. 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 filariae, filariasis often develops lymphangitis, lymphedema of the extremities with swelling of the mammary glands and genital organs. With echonococcosis, cysts of the liver and lungs occur, with suppuration of which complications are possible in the form of purulent peritonitis or pleurisy.
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.
On the basis of clinical and epidemiological data, helminthiases are mainly diagnosed already in the chronic stage. To identify the causative agent of helminthiasis, special laboratory methods are used: microhelminthoscopic (scraping for enterobiosis), helmintho-ovoscopic (examination of feces for worm eggs), helmintholarvoscopic, serological (ELISA, RIF, RSK, RNGA), histological scatology. Feces, vomit, duodenal contents, sputum, urine, blood, skin biopsy specimens, etc.
With intestinal helminthiasis, skin-allergic 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.
Treatment of helminthiases
A holistic approach to the treatment of helminthiases consists of etiotropic and post-syndromic therapy. Specific treatment involves the appointment of anthelmintic drugs, taking into account the type of helminth and the stage of invasion. The effectiveness of deworming is assessed by the results of a repeated parasitological examination. For the etiotropic therapy of helminthiases, the following groups of drugs are used:
- broad-spectrum drugs.
In intestinal helminthiases, antibacterial drugs, enterosorbents, enzymes, probiotics, etc. are added to the main treatment. Symptomatic therapy of helminthiases may include the appointment of antihistamines, intravenous infusions, vitamins, cardiac glycosides, NSAIDs, glucocorticoids. With echinococcosis, the main method of treating patients is surgical intervention (surgery for a cyst / abscess of the liver, echinococcectomy).
Prevention of geohelminthiasis is carried out by hygienic education of the population, environmental protection from fecal pollution, 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 helminthiases, the disruption of the transmission mechanism of pathogens in organized, mainly children's, groups is of primary importance. It is advisable to carry out seasonal drug prophylaxis of helminthiases in families (for example, with albendazole), regular parasitological examination of children and risk groups.