Helminthiasis (helminth infestation): causes, symptoms, diagnosis and methods of treatment.
Frdetermination
Helminthiasis are diseases of humans, animals and plants caused by parasitic worms (helminths).
Causes of helminthiasis
Currently in our country there are more than 70 species of the known 250 helminths that parasitize the human body.The most common are roundworms (roundworms, pinworms, trichinella, whipworm), tapeworms (pork, beef and dwarf tapeworms, broad tapeworm, echinococcus), and flukes (liver and cat flukes).
Helminths are characterized by stages of development: eggs → larvae → sexually mature forms.
Infection with helminths most often occurs after their eggs and/or larvae enter the body.Depending on the mechanism of infection and the ways of transmission, helminthiasis are divided into: geohelminthiasis, biohelminthiasis and contact helminthiasis.Geohelminths develop without intermediate hosts, biohelminths develop with a sequential change of one, two or three hosts, contact helminths are transmitted by contact.
The pig tapeworm, the beef tapeworm, the echinococcus and other types of helminths develop by successively changing one, two or three hosts.Intermediate hosts can be fish, molluscs, crustaceans and insects.A person becomes infected with these helminths by eating foods that have not undergone complete heat treatment:
- beef infected with beef tapeworm larvae;
- pork affected by Finnish pork tapeworm;
- lightly salted and raw fish with opisthorchis larvae or broad tapeworm;
- raw water or vegetables and fruits treated with this water.
Whipworm, roundworm, hookworm and nekator develop without intermediate hosts.The eggs and larvae of these parasites fall into the soil with feces.If the rules of personal hygiene are not observed, they penetrate into the body of a new host.
By contact - ie.by personal contact between a healthy person and an infected person, by using common utensils, toiletries, bed linen and by inhaling dust in a room where an infected person is - enterobiosis (causing agent - pinworms) and hymenolepiasis (pathogen - dwarf tapeworm) are transmitted.In the case of enterobiosis, self-infection often occurs.
Helminths of a certain type parasitize certain organs, causing various helminthiasis:
- in the large intestine - pork, beef, dwarf tapeworms, nematodes (hookworms, roundworms, strongyloides), pinworms, whipworms.From the intestinal lumen, the larvae of the pig tapeworm can enter the bloodstream and spread throughout the body, settling in fat tissue, muscle vessels, chambers of the eye and brain;
- in the liver and bile ducts - trematodes (opistorchis, clonorchis, fasciola).Echinococcal cysts are mainly located in the liver, and after their rupture, daughter cysts can be found in the mesentery, peritoneal layers, spleen and other organs;
- in the respiratory organs - echinococci, alveococci, lung flukes, causing paragonimosis;
- in the nervous system - schistosomiasis, paragonimosis, echinococcosis and alveococcosis;
- in the organs of vision - onchocercosis, loiasis, complicated forms of taeniasis;
- in the circulatory system - nekatoriasis, schistosomiasis, diphyllobothriasis;
- in the lymphatic system - filariasis, trichinellosis;
- in the skin and subcutaneous tissue - hookworm, onchocerciasis, loiasis, larval stage of schistosomiasis;
- in the bone system - echinococcosis;
- in skeletal muscles - trichinellosis, cysticercosis of muscle tissue.
The duration of life of helminths in the body of the final host can be different, depends on the type of parasite and varies from a few weeks (spindles) to several years (tapeworms) and decades (fasciola).
Classification of the disease
There are two types of worms that parasitize humans:
- Nemathelminthes – roundworms, class Nematoda;
- Plathelminthes are flatworms, which include the class Cestoidea - tapeworms, Trematoda - class flukes.
Depending on the ways of spread of parasites and the peculiarities of their biology, the following are distinguished:
- biohelminthiasis;
- geohelminthiases;
- contact helminth infections.
Symptoms of helminthiasis
Helminths have different effects on the human body:
- antigenic effects when local and general allergic reactions develop;
- toxic effect (waste products of helminths cause malaise, weakness, dyspeptic symptoms);
- traumatic effect (when the parasites are fixed to the intestinal wall, the blood supply is disturbed with necrosis and subsequent atrophy of the mucous membrane; absorption processes may be disturbed; mechanical compression of tissues by helminths);
- secondary inflammation as a result of penetration of bacteria after migrating larvae of helminths;
- disturbance of metabolic processes;
- anemia occurs as a result of the absorption of blood by some helminths;
- nerve-reflex effect - irritation of nerve endings by helminths provokes bronchospasm, intestinal dysfunction, etc.;
- psychogenic effect manifested by neurotic states, sleep disorders;
- immunosuppressive effect.
Helminthiasis is characterized by stages of development.Each stage is characterized by its own clinical symptoms.
In the initial acute stage, helminths most often do not yet release eggs, sensitization of the body occurs (production of antibodies, release of inflammatory mediators, increased permeability of the vascular wall) and traumatization of the organs through which the larvae migrate.Clinical symptoms may be absent, but in some cases the disease may proceed with pronounced clinical manifestations.The acute stage lasts from 1 to 4 months, sometimes 8-10 months or more.
Complaints from patients in the acute stage:
- elevated temperature from several days to two months (subfebrile temperature or above 38ºС, accompanied by chills, severe weakness and sweating);
- itchy recurring skin rashes;
- local or generalized edema;
- enlargement of regional lymph nodes;
- muscle and joint pain;
- cough, asthma attacks, chest pain, prolonged catarrhal symptoms, bronchitis, tracheitis, symptoms simulating pneumonia, asthmatic syndrome, hemoptysis;
- abdominal pain, nausea, vomiting, stool disorders.
At the end of this stage of helminth infections, acute allergic phenomena gradually subside, and the clinic of the chronic stage has not yet had time to develop.
The acute stage passes into a subacute one, when the "young" helminths gradually mature.Then comes the chronic stage, corresponding to the development of the parasites in sexually mature individuals.The clinical picture develops against the background of the toxic effect of waste products of helminths, the traumatic effect of helminths on organs (hookworm, trichuriasis, etc.), mechanical effects (echinococcal cyst in the liver grows, compresses neighboring organs; cysticerci - in the brain), secondary inflammatory process (duodenitis is observed in strongyloidosis), metabolic disorders (hypo- or avitaminosis), functional disorders of the stomach andduodenum, secondary immunodeficiencies, etc.
Symptoms depend on the organs in which the helminths parasitize, their size and quantity.
Forintestinal helminthiasesThe following syndromes are characteristic:
- dyspepsia (stomach discomfort, feeling of fullness after eating, early satiety, bloating, nausea);
- painful;
- asthenoneurotic (feeling of severe fatigue, increased nervous excitability and irritability).
Enterobiasis is characterized by nocturnal perianal itching.In case of massive infection with roundworms, there may be intestinal obstruction, pancreatitis, obstructive jaundice.
Intestinal cestodes(taeniarinhoz, diphyllobothriasis, hymenolepiasis, taeniasis and others) are asymptomatic or with a small number of symptoms (with symptoms of dyspepsia, pain, anemia).
Liver trematodes(fascioliasis, opisthorchiasis, clonorchiasis) cause:
- chronic pancreatitis;
- hepatitis;
- cholecystocholangitis;
- neurological disorders.
Hookwormmanifested by asthenovegetative syndrome (weakness, fatigue, pallor of the skin) due to the development of iron deficiency anemia.
Filariasis is characterized by an allergic syndrome of varying severity and regional lymphadenitis.
Urogenital schistosomiasismanifested by the appearance of blood at the very end of urination, frequent urge to urinate, pain during urination.
Alveococcosis, cysticercosis, echinococcosismay remain asymptomatic for a long time.At a later stage, suppuration or rupture of cysts containing parasites leads to anaphylactic shock, peritonitis, pleurisy and other severe consequences.
For diseases caused by parasitization of migrating larvaezoohelminthswhen a person is not a natural host, distinguishes between cutaneous and visceral form.The skin form is caused by the penetration of some animal helminths under the human skin: schistosomatids of waterfowl (trematodes), hookworms of dogs and cats, strongylids (nematodes).When a person comes into contact with soil or water, helminth larvae penetrate through the skin.There is a feeling of burning, tingling or itching at the site of introduction of the helminth.There may be a short-term fever and signs of general malaise.After 1-2 weeks (less often 5-6 weeks) recovery occurs.
The visceral form develops as a result of ingestion of helminth eggs with water and food.At the beginning of the disease, there may be malaise, allergic exanthema (skin rash).In the human intestine, the larvae hatch from helminth eggs, penetrate through the intestinal wall into the blood, reach the internal organs, where they grow and reach 5-10 cm in diameter, press the tissues and disrupt the function of the organs.When tapeworm larvae (cysticerci, cenura) are found in the membranes and substance of the brain, headaches, signs of cerebral hypertension, paresis and paralysis, epileptiform seizures are observed.Larvae can also be located in the spinal cord, eyeball, serous membranes, intermuscular connective tissue, etc.
The result of helminthiasis can be a complete recovery with the elimination of helminths or the development of irreversible changes in the host's body.
Diagnosis of helminthiasis
The diagnosis of helminthiasis is established based on a combination of complaints, information received from the patient about the course of the disease, data from laboratory and instrumental research methods.
In the acute phase of helminth infections, there is a blood reaction to the presence of helminths in the body, which is why the following tests are recommended:
- clinical blood test: general analysis, leukoformula, ESR (with microscopy of a blood smear in the presence of pathological changes);
- biochemical blood test:
- total protein, albumin, protein fractions;
- assessment of renal function indicators (urea, creatinine, glomerular filtration);
- assessment of liver function indicators (bilirubin, ALT, AST, alkaline phosphatase);
- pancreatic alpha-amylase;
- assessment of carbohydrate metabolism: glucose (in blood), glucose tolerance test with determination of glucose in venous blood on an empty stomach and after physical exertion after 2 hours.
The following biological materials can be examined for the presence of helminths: feces, blood, urine, duodenal contents, bile, sputum, muscle tissue, rectal and perianal mucus.
Since helminths are not excreted in the feces at any stage of their development, it is recommended to give feces three times - every 3-4 days.
- Fecal analysis for helminth eggs.
- Test for enterobiosis (eggs of pinworms), swab.
- Microscopic examination of feces for the detection of eggs of the enterobiosis pathogen Enterobius vermicularis (sedges).
- Test for enterobiosis (sedge eggs), spatula.
- The analysis is necessary if pinworm infection is suspected, as well as during hospitalization and registration of a medical record.
- Analyzes for kindergarten and school.
The Child Screening Program is intended to be completed prior to entering kindergarten or school.The results of these tests are necessary to obtain a medical certificate according to form 026U approved by the Ministry of Health of the Russian Federation.
Conducting immunological studies - determination of specific antibodies against helminths:
- anti-roundworm antibodies IgG;
- anti-Echinococcus IgG;
- IgG antibodies to Toxocar antigens;
- Anti-Opisthorchis felineus IgG (IgG class of antibodies against cat flu antigens);
- IgG antibodies to trichinella antigens;
- antibodies to the causative agent of anisakiasis (nematodes of the genus Anisakis), IgG;
- antibodies against the causative agent of clonorchiasis, IgG;
- Antibodies against Strongyloides stercoralis, the causative agent of strongyloidiasis, IgG.
A test aimed at detecting IgG antibodies to the causative agent of strongyloidosis is used for early serological diagnosis of strongyloidosis in cases of clinical suspicion (eosinophilia, snake-like skin lesions, pulmonary or gastrointestinal symptoms) of this disease.
In difficult cases, the following tests can be recommended:
- plain chest x-ray;
- comprehensive ultrasound examination of abdominal organs (liver, gall bladder, pancreas, spleen);
- CT scan of the abdominal cavity and retroperitoneum;
- CT scan of the chest and mediastinum;
- CT of the brain and skull.
Which doctors should I contact?
If you suspect helminthiasis, you should consult a therapist or general practitioner, and visit a pediatrician with your child.
If there are indications for surgical treatment, the patient is referred to a surgeon.
Treatment of helminthiasis
Most people with helminth infections do not need hospitalization.In a hospital, patients with tissue helminthiasis are treated, regardless of severity, as well as patients with a severe and complicated course of the disease.
Therapy is carried out with anthelmintic drugs.The frequency of administration and the dosage of the drug depend on the age and body weight of the patient and are determined by the doctor.
Desensitization, detoxification therapy, and vitamin therapy may be indicated.To lower the temperature, non-steroidal anti-inflammatory drugs are prescribed, in case of an allergic reaction and itching - antihistamines, in case of severe edema - diuretics.In severe cases, hormonal drugs are needed.
The presence of helminths in organs and tissues may be an indication for surgical treatment.
Complications
- Bronchial asthma.
- Pneumonia.
- Colon cancer.
- Cirrhosis.
- Portal hypertension.
- Gastrointestinal bleeding.
- Ascites.
- Hepatitis.
- Liver abscess.
- peritonitis.
- Allergic myocarditis.
- Meningoencephalitis.
- Chronic glomerulonephritis.
- Chronic kidney disease.
- Disorders of hemostasis.
- Loss of vision.
Prevention of helminthiasis
Preventive measures aimed at preventing helminth infection include:
- compliance with the rules of personal hygiene (use of an individual towel, personal hygiene items and other accessories for daily use);
- use only high-quality water in everyday life;
- regular vaccination and deworming of pets;
- Thorough washing of vegetables, fruits, fruits before consumption;
- sufficient heat treatment of meat and fish products.
IMPORTANT!The information in this section cannot be used for self-diagnosis and self-treatment.In case of pain or other exacerbation of the disease, diagnostic tests should be prescribed only by the attending physician.In order to make a diagnosis and correctly prescribe treatment, you should contact your doctor.