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Helminthiasis

Helminthiasis (helminthic infestation): causes, symptoms, diagnosis and treatment methods.

HEdetermination

Helminthiasis are diseases of humans, animals and plants caused by parasitic worms (helminths).

Causes of helminthiasis

Currently, more than 70 species of the 250 known helminths that parasitize the human body live in Hungary.The most common are roundworms (roundworms, pinworms, trichinella, whipworms), tapeworms (pig, cattle and dwarf tapeworms, broad tapeworm, echinococcus) and flukes (liver and cat worms).

Helminths are characterized by developmental stages: eggs → larvae → mature forms.

Infection with helminths most often occurs after their eggs and/or larvae enter the body.Depending on the mechanism of infection and transmission routes, helminthiasis can be divided into geohelminthiasis, biohelminthiasis, and contact helminthiasis.Geohelminths develop without an intermediate host, biohelminths develop with a sequential change of one, two or three hosts, contact helminths are spread by contact.

types of dangerous helminths

Pig tapeworm, cattle tapeworm, echinococcus, and other types of worms develop by changing one, two, or three hosts in succession.Intermediate hosts can be fish, molluscs, crustaceans and insects.A person becomes infected with these helminths if he eats food that has not undergone complete heat treatment:

  • beef infected with bovine tapeworm larvae;
  • pork affected by Finnish pork tapeworm;
  • lightly salted and raw fish with opisthorchis or broad tapeworm larvae;
  • raw water or vegetables and fruits treated with this water.

Whipworms, roundworms, hookworms and necators develop without an intermediate host.The eggs and larval forms of these parasites enter the soil with faeces.If personal hygiene rules are not followed, they will invade the body of a new host.

life cycle of roundworms

Enterobiasis (pathogen - fungal tapeworm) and hymenolepiasis (pathogen - dwarf tapeworm) are spread by contact - i.e. by personal contact between a healthy person and an infected person, by using shared dishes, toiletries, bedding, and by breathing dust in a room where the infected person is.Self-infection often occurs with enterobiasis.

A certain type of helminths parasitizes certain organs, causing various helminthiasis:

  • in the large intestine - pigs, cattle, dwarf tapeworms, nematodes (hookworms, roundworms, strongyloides), pinworms, whipworms.From the lumen of the intestine, the larvae of the pig tapeworm can enter the bloodstream and spread throughout the body, settling in adipose tissue, isomers, eye chambers and brain;
  • in the liver and bile ducts - trematodes (opisthorchis, clonorchis, fasciola).Echinococcal cysts are primarily located in the liver, after their rupture the daughter cysts are found in the intestinal fold, peritoneal layers, spleen and other organs;
  • in the respiratory organs - echinococcus, alveococcus, lung flukes, causing paragonimiasis;
  • in the nervous system - schistosomiasis, paragonimiasis, echinococcosis and alveococcosis;
  • in the organs of vision - onchocerciasis, loiasis, complicated forms of taeniasis;
  • in the circulatory system - necatoriasis, schistosomiasis, diphyllobothriasis;
  • in the lymphatic system - filariasis, trichinosis;
  • in the skin and subcutaneous tissue - the larval stage of hookworm, oncocerciasis, loiasis, schistosomiasis;
  • in the skeletal system - echinococcosis;
  • in skeletal muscles - trichinosis, muscle tissue cysticercosis.

The lifespan of intestinal worms in the body of the definitive host can vary, depending on the type of parasite, and can range from a few weeks (needleworm) to several years (tapeworm) and decades (fasciola).

Classification of the disease

Two types of worms parasitize humans:

  • Nemathelminthes – roundworms, class Nematoda;
  • Plathelminths are flatworms that belong to the Cestoidea - tapeworms, Trematoda - class of worms.

Depending on the route of spread of parasites and the characteristics of their biology, they 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 (excreta of helminths cause malaise, weakness, dyspeptic symptoms);
  • traumatic effect (if the parasites are attached to the intestinal wall, the blood supply is interrupted with necrosis and subsequent atrophy of the mucous membrane; absorption processes may be interrupted; mechanical compression of tissues by helminths);
  • secondary inflammation due to the penetration of bacteria following the migrating helminth larvae;
  • violation of metabolic processes;
  • anemia occurs as a result of absorption of blood by some helminths;
  • neuro-reflex effect - irritation of nerve endings by intestinal worms causes bronchospasm, intestinal dysfunction, etc.
  • psychogenic effect, which manifests itself in neurotic states and sleep disorders;
  • immunosuppressive effect.

Helminthiases are 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 (production of antibodies, release of inflammatory mediators, increased permeability of the vessel wall) and traumatization of the organs through which the larvae migrate.Clinical symptoms may be absent, but in some cases the disease may present with pronounced clinical manifestations.The acute stage lasts 1-4 months, sometimes 8-10 months or more.

Complaints of patients in the acute stage:

  • increased temperature from several days to two months (low-grade fever or above 38 ° C, accompanied by chills, severe weakness and sweating);
  • recurring itchy 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, the acute allergic phenomena gradually disappear, and the clinic of the chronic stage has not yet had time to develop.

The acute phase becomes subacute when the "young" helminths gradually mature.Then comes the chronic phase, which corresponds to the development of parasites into sexually mature individuals.The clinical picture is due to the toxic effect of intestinal worm waste products, the traumatic effect of worms on organs (hookworm, trichuriasis, etc.), mechanical effects (echinococcus cyst grows in the liver and compresses neighboring organs; cysticerci - in the brain), secondary inflammatory process (in the brain), functional inflammatory process (duodenitis), metabolic disorders (duodenitis),severe vitaminosis develops against the background of metabolic disorders.gastrointestinal disorders, secondary immune deficiencies, etc.

The symptoms depend on the organs in which the helminths are parasitized, their size and quantity.

Becauseintestinal helminthiasisThe following syndromes are typical:

  • dyspeptic (stomach discomfort, fullness after eating, early satiety, bloating, nausea);
  • painful;
  • astenoneurotic (feeling of extreme fatigue, increased nervous excitability and irritability).

Enterobiasis is characterized by perianal itching at night.In the case of a massive roundworm infection, intestinal obstruction, pancreatitis, and obstructive jaundice may occur.

Intestinal cestodosis(for taeniarin, diphyllobothriasis, hymenolepiasis, taeniasis and others) asymptomatic or with a small number of symptoms (dyspepsia, pain, symptoms of anemia).

Liver trematodes(fascioliasis, opisthorchiasis, clonorchiasis) causes:

  • chronic pancreatitis;
  • hepatitis;
  • cholecystocholangitis;
  • neurological disorders.

Hookworm diseasemanifests itself with asthenovegetative syndrome (weakness, fatigue, pale skin) due to the development of iron-deficiency anemia.

Filariasis is characterized by an allergic syndrome of varying severity and regional lymphadenitis.

Urogenital schistosomiasisit manifests itself in the appearance of blood at the very end of urination, a frequent urge to urinate, and 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 serious consequences.

For diseases caused by the wandering larvae parasitezoohelminthswhen a person is not the natural host, distinguish between skin and visceral forms.The shape of the skin is caused by the penetration of certain animal worms under the human skin: schistosomatids (trematodes) of waterfowl, hookworms of dogs and cats, strongylids (nematodes).When a person comes into contact with soil or water, helminth larvae penetrate the skin.There is a burning sensation, tingling or itching at the place of introduction of the helminth.Short-term fever and signs of general malaise may occur.Healing occurs after 1-2 weeks (less often 5-6 weeks).

The visceral form develops as a result of ingestion of helminth eggs with water and food.At the beginning of the disease, malaise and allergic exanthema (skin rash) may occur.In the human intestine, the larvae hatch from the eggs of the intestinal worm, penetrate through the intestinal wall into the blood, reach the internal organs, where they grow and reach a diameter of 5-10 cm, compress the tissues and disrupt the functioning of the organs.If the larvae of the tapeworm (cysticerci, tsenura) are located in the membrane and substance of the brain, headache, signs of cerebral hypertension, paresis and paralysis, and epileptiform convulsions can be observed.The larvae live in the spinal cord, eyeball, serous membranes, intermuscular connective tissue, etc.

The result of helminthiasis can be complete recovery with the elimination of helminths or the development of irreversible changes in the host.

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, and data from laboratory and instrumental examination methods.

In the acute phase of worm infections, a blood reaction occurs to the presence of the worm in the body, so the following tests are recommended:

  • clinical blood test: general analysis, leukoformula, ESR (blood smear with a microscope in the presence of pathological changes);
  • biochemical blood test:
  • total protein, albumin, protein fractions; 
  • assessment of kidney 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 venous blood glucose on an empty stomach and 2 hours after exercise.

The following biological materials can be tested for the presence of intestinal worms: feces, blood, urine, duodenal contents, bile, sputum, muscle tissue, rectal and perianal mucus.

Since intestinal worms do not pass out with faeces at any stage of their development, it is recommended to donate faeces three times - every 3-4 days.

  • Analysis of feces for helminth eggs.
  • Examination of enterobiasis (pinworm eggs), swab.
  • Microscopic examination of feces for the detection of Enterobius vermicularis (pinworms) eggs that cause enterobiasis.
  • Test for enterobiasis (pinworm eggs), spatula.
  • The analysis is necessary when there is a suspicion of a fungal infection, as well as during hospitalization and medical records.
  • Analyzes for kindergarten and school.

The children's examination program is intended to be completed before entering kindergarten and school.The results of these tests are necessary to obtain a medical certificate in accordance with form 026U approved by the Ministry of Health of the Russian Federation.

Carrying out immunological tests - determination of specific antibodies against helminths:

  • antibodies against roundworm IgG;
  • IgG against Echinococcus;
  • IgG antibodies against Toxocar antigens;
  • Anti-Opisthorchis felineus IgG (IgG class antibodies against cat distemper antigens);
  • IgG antibodies against Trichinella antigens;
  • antibodies against the causative agent of anisakiasis (nematodes of the genus Anisakis), IgG;
  • antibodies against IgG, the causative agent of clonorchiasis;
  • Antibodies against Strongyloides stercoralis, the causative agent of strongyloidiasis, IgG.

The test for the detection of IgG antibodies against the causative agent of strongyloidiasis is used for the early serological diagnosis of strongyloidiasis in case of clinical suspicion of the disease (eosinophilia, serpentine skin lesions, pulmonary or gastrointestinal symptoms).

In difficult cases, the following tests can be recommended:

  • simple x-ray of chest organs;
  • comprehensive ultrasound examination of the abdominal organs (liver, gall bladder, pancreas, spleen);
  • CT examination of the abdominal cavity and retroperitoneum;
  • CT scan of the chest and mediastinum;
  • CT scan of the brain and skull.

Which doctor should I see?

If you suspect helminthiasis, consult a therapist or general practitioner and take your child to a pediatrician.

If surgical treatment is indicated, the patient is referred to a surgeon.

Treatment of helminthiasis

Most people with helminth infections do not require hospital treatment.Patients with tissue helminthiasis, regardless of severity, as well as patients with a severe and complicated course of the disease, are treated in a hospital.

The therapy is carried out with anthelmintic drugs.The frequency and dosage of the drug depends on the patient's age and body weight and is determined by the doctor.

Desensitizing, detoxifying therapy and vitamin therapy are recommended.In order to reduce 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 worms in organs and tissues may be an indication for surgical treatment.

Complications

  • Bronchial asthma.
  • Pneumonia.
  • Bowel cancer.
  • Cirrhosis.
  • Portal hypertension.
  • Gastrointestinal bleeding.
  • Ascites.
  • Hepatitis.
  • Liver abscess.
  • Peritonitis.
  • Allergic myocarditis.
  • Meningoencephalitis.
  • Chronic glomerulonephritis.
  • Chronic kidney disease.
  • Disorders of hemostasis.
  • Vision loss.

Prevention of helminthiasis

Preventive measures to prevent helminth infection include:

  • compliance with personal hygiene rules (using an individual towel, personal hygiene items and other daily accessories);
  • use only high-quality water in everyday life;
  • regular vaccination and deworming of pets;
  • Thorough washing of vegetables, fruits and berries before consumption;
  • proper heat treatment of meat and fish products.
With pets, children in children's groups, contact with the earth, the hobby of fishing or hunting, frequent trips to exotic countries, prevention can be achieved through the use of medicines.Medicinal prophylaxis must be used by the whole family twice a year (for example, in spring and autumn).

IMPORTANT!

The information in this section should not be used for self-diagnosis and self-treatment.In case of pain or other aggravation of the disease, diagnostic tests can only be prescribed by the attending physician.Consult your doctor to establish a diagnosis and prescribe the appropriate treatment.