Helminthiasis (helminth infestation): causes, symptoms, diagnosis and treatment methods.
Ohdetermination
Helminthiases are diseases of humans, animals and plants caused by parasitic worms (helminths).
Causes of helminthiasis
Currently, more than 70 of the 250 known species of helminths parasitizing the human body are found in our country.The most common are roundworms (roundworms, pinworms, trichinella, whipworms), tapeworms (swine, bovine and dwarf tapeworms, broad tapeworm, echinococcus) and trematodes (liver and cat flukes).
Helminths are characterized by developmental stages: eggs → larvae → sexually mature forms.
Helminth infection most often occurs after their eggs and/or larvae have entered the body.Depending on the mechanism of infection and the routes of transmission, helminthiasis is 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.
Pork tapeworms, bovine tapeworms, echinococcus and other types of worms develop with a subsequent change of 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 thorough heat treatment:
- beef infected with bovine tapeworm larvae;
- pork affected by Finnish swine tapeworm;
- lightly salted and raw fish with opisthorchis or tapeworm larvae;
- raw water or fruits and vegetables treated with this water.
Whipworm, roundworm, hookworm, and necator develop without intermediate hosts.The eggs and larval forms of these parasites enter the soil in feces.If the rules of personal hygiene are not respected, they penetrate the body of the new host.
By contact - that is, through personal contact between a healthy person and an infected person, through the use of shared utensils, toiletries, linen and through inhalation of dust in the room where an infected person is located - enterobiasis (pathogen - pinworm) and hymenolepiasis (pathogen - dwarf tapeworm) are transmitted.In the case of enterobiasis, autoinfection often occurs.
Helminths of a certain type parasitize in some organs, causing various helminthiases:
- in the large intestine - pig, cattle, dwarf tapeworms, roundworms (hookworms, roundworms, strongyloides), pinworms, whipworms.From the intestinal lumen, pork tapeworm larvae can enter the bloodstream and spread throughout the body, settling in adipose tissue, muscle vessels, eye chambers and brain;
- in the liver and biliary tract - trematodes (opisthorchis, clonorchis, fasciola).Echinococcal cysts are found primarily in the liver, and after their rupture, daughter vesicles may be found in the mesentery, peritoneal layers, spleen, and other organs;
- in the respiratory organs - echinococci, alveococci, 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: hookworm, onchocerciasis, loiasis, larval stage of schistosomiasis;
- in the skeletal system - echinococcosis;
- in skeletal muscles - trichinosis, cysticercosis of muscle tissue.
The lifespan of helminths in the body of the definitive host can be different, depends on the type of parasite and varies from a few weeks (pinworms) to several years (tapeworms) and decades (fasciola).
Classification of the disease
There are two types of worms that parasitize humans:
- Nematelminths – nematodes, class Nematoda;
- Flatworms are flatworms, which include the classes Cestoidea - tapeworms, and Trematoda - the class of trematodes.
Depending on the ways of diffusion of the parasites and the characteristics of their biology, the following are distinguished:
- biohelminthiasis;
- geohelminthiasis;
- contact helminth infections.
Symptoms of helminthiasis
Helminths have several 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 parasites attach to the intestinal wall, the blood supply is interrupted with necrosis and subsequent atrophy of the mucosa; absorption processes can be interrupted; mechanical compression of tissues by helminths);
- secondary inflammation following the penetration of bacteria following the migration of helminth larvae;
- violation of metabolic processes;
- due to the absorption of blood by some helminths, anemia occurs;
- neuro-reflex effect: irritation of nerve endings by helminths causes bronchospasm, intestinal dysfunction, etc.;
- psychogenic effect, manifested by neurotic conditions, sleep disorders;
- immunosuppressive effect.
Helminthiases are characterized by developmental stages.Each phase is characterized by its own clinical symptoms.
In the initial acute phase, 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 can manifest itself with pronounced clinical manifestations.The acute phase lasts 1 to 4 months, sometimes 8-10 months or more.
Complaints from patients in the acute phase:
- increased temperature from several days to two months (mild fever or above 38ºС, accompanied by chills, severe weakness and sweating);
- recurrent itchy skin rashes;
- local or generalized edema;
- swollen regional lymph nodes;
- muscle and joint pain;
- cough, asthma attacks, chest pain, prolonged catarrhal symptoms, bronchitis, tracheitis, symptoms simulating pneumonia, asthma 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 becomes subacute as “young” helminths gradually mature.Then comes the chronic stage, corresponding to the development of parasites in sexually mature individuals.The clinical picture develops against the background of the toxic effect of helminth waste products, the traumatic effect of helminths on organs (hookworm, trichuriasis, etc.), mechanical effects (an echinococcal cyst in the liver grows, compresses nearby organs; cysticerci - in the brain), a secondary inflammatory process (duodenitis is observed in strongyloidosis), metabolic disorders (hypo- or avitaminosis), functional disorders of the stomach andduodenum, secondary immunodeficiency disorders, etc.
The symptoms depend on the organs in which the helminths parasitize, their size and quantity.
Forintestinal helminthiasisThe following syndromes are characteristic:
- dyspeptic (stomach discomfort, feeling of fullness after eating, early satiety, bloating, nausea);
- painful;
- asthenoneurotic (feeling of extreme tiredness, increased nervous excitability and irritability).
Enterobiasis is characterized by nocturnal perianal itching.With massive roundworm infestation, intestinal obstruction, pancreatitis, obstructive jaundice may occur.
Intestinal cestodosis(taeniarinhoz, diphyllobothriasis, hymenolepiasis, taeniasis and others) are asymptomatic or with a small number of symptoms (with symptoms of dyspepsia, pain, anemia).
Liver flukes(fascioliasis, opisthorchiasis, clonorchiasis) cause:
- chronic pancreatitis;
- hepatitis;
- cholecystocholangitis;
- neurological disorders.
Hookworm diseasemanifested by asthenovegetative syndrome (weakness, fatigue, paleness 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 schistomiasismanifested by the appearance of blood at the end of urination, frequent need 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 serious consequences.
For diseases caused by the parasitism of migratory larvaezoohelmintheswhen a person is not the natural host, distinguish between cutaneous and visceral forms.The cutaneous 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 the skin.A burning, tingling or itching sensation is felt at the site of introduction of the helminth.Short-term fever and signs of general malaise may occur.After 1-2 weeks (less often 5-6 weeks) recovery occurs.
The visceral form develops following ingestion of helminth eggs with water and food.At the onset of the disease, malaise, allergic exanthema (skin rash) may occur.In the human intestine, larvae hatch from helminth eggs, penetrate the blood through the intestinal wall, reach the internal organs, where they grow and reach 5-10 cm in diameter, compress tissues and disrupt the function of organs.When tapeworm larvae (cysticerci, tsenura) are found in the membranes and substance of the brain, headaches, signs of cerebral hypertension, paresis and paralysis, and epileptiform convulsions are observed.Larvae can also be located in the spinal cord, eyeball, serous membranes, intermuscular connective tissue, etc.
The outcome of helminthiasis can be 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 on the basis of a combination of complaints, information received from the patient about the course of the disease, data from laboratory and instrumental examination methods.
In the acute phase of helminth infections, a blood reaction occurs to the presence of helminths in the body, therefore the following studies 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 proteins, albumin, protein fractions;
- evaluation of renal function indicators (urea, creatinine, glomerular filtration);
- evaluation of liver function indicators (bilirubin, ALT, AST, alkaline phosphatase);
- pancreatic alpha-amylase;
- evaluation of carbohydrate metabolism: glucose (in the blood), glucose tolerance test with determination of glucose in venous blood on an empty stomach and after exercise 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 feces at any stage of their development, it is recommended to donate feces three times, every 3-4 days.
- Stool analysis for helminth eggs.
- Test for enterobiasis (pinworm eggs), swab.
- Microscopic examination of feces to detect eggs of the enterobiasis pathogen Enterobius vermicularis (pinworms).
- Test for enterobiasis (pinworm eggs), spatula.
- The analysis is necessary if there is suspicion of pinworm infection, as well as during hospitalization and registration of medical records.
- Analysis for nursery schools and schools.
The children's examination program must be completed before entering kindergarten or school.The results of these studies are necessary to obtain a medical certificate according to form 026U approved by the Ministry of Health of the Russian Federation.
Conduct immunological studies - determination of specific antibodies against helminths:
- antibodies against nematode IgG;
- anti-Echinococcus IgG;
- IgG antibodies against Toxocar antigens;
- Anti-Opisthorchis felineus IgG (IgG class antibodies against cat fluke antigens);
- IgG antibodies against Trichinella antigens;
- antibodies against 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 strongyloidosis, IgG.
A test aimed at detecting IgG antibodies against the causative agent of strongyloidosis is used for early serological diagnosis of strongyloidosis in case of clinical suspicion (eosinophilia, serpentine skin lesions, pulmonary or gastrointestinal symptoms) of this disease.
In difficult cases, the following studies may be recommended:
- plain x-ray of the chest organs;
- complete ultrasound examination of the abdominal organs (liver, gallbladder, pancreas, spleen);
- CT scan of the abdominal cavity and retroperitoneum;
- CT scan of the chest and mediastinum;
- CT scan of the brain and skull.
Which doctors should I contact?
If you suspect helminthiasis, you should consult a therapist or general practitioner, and with your child, consult a pediatrician.
If there are indications for surgical treatment, the patient is referred to a surgeon.
Treatment of helminthiasis
Most people with helminth infections do not require hospitalization.Patients with tissue helminthiasis, regardless of severity, and patients with severe and complicated course of the disease are treated in hospital.
Therapy is carried out with anthelmintic drugs.The frequency of administration and dosage of the drug depend on the patient's age and body weight and are established by the doctor.
Desensitizing, detoxifying, and vitamin therapy may be indicated.To reduce the temperature, nonsteroidal anti-inflammatory drugs are prescribed, for an allergic reaction and itching - antihistamines, for severe edema - diuretics.In more severe cases, hormonal drugs are necessary.
The presence of helminths 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.
- Hemostasis disorders.
- Loss of vision.
Prevention of helminthiasis
Preventive measures aimed at preventing helminth infection include:
- compliance with personal hygiene rules (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, berries 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.To make a diagnosis and correctly prescribe treatment, you need to contact your doctor.