Cysticercosis - Causes, Signs, Symptoms And Treatment

2023 Author: Riley Dean | [email protected]. Last modified: 2023-11-27 09:15

Cysticercosis is a disease caused by the Finns bovine tapeworm. Pork tapeworm eggs enter the body through the fecal-oral route and are carried with the blood stream to all organs and systems. The larvae have a negative effect on body tissues, causing irritation and intoxication. There are various forms of the disease: cysticercosis of the brain and spinal cord, eyes, heart, skin, lungs. The most severe form of the disease is cysticercosis of the brain (neurocysticercosis).

The content of the article:

1 Reasons for the development of cysticercosis
2 Path of infection
3 Provoking factors of cysticercosis
4 Pathogenic effect of cysticercus in the human body
5 What Happens During Cysticercosis
6 Types of disease
7 Symptoms of cysticercosis
- 7.1 Cysticercosis of the central nervous system
- 7.2 Cysticercosis of the eyes
- 7.3 Cysticercosis of the skin and subcutaneous fat
8 Diagnosis of cysticercosis
9 Treatment of cysticercosis

9.1 Treatment methods:
10 Prevention of cysticercosis

The reasons for the development of cysticercosis

The causative agent of cysticercosis is the larval stage of the pork tapeworm (Taenia solium), cysticercus or Finn (Cysticercus cellulosae). The cysticercus is an oval-shaped formation or vesicle in which the scolex or the head of the pork tapeworm is located, equipped with 4 suction cups and a double-row crown of hooks (hence the name "armed tapeworm").

In the tissues and organs of the patient, the shape can change from round to spindle-shaped in size up to 15 mm, however, giant bubbles with cluster-shaped branches (the so-called branched form of cysticercus) are rarely described. Over time, the membrane becomes denser, which is associated with deposits of calcium salts in it, however, the cysticercus inside is still viable.

The source of infection is a sick person, with whose feces eggs of pork tapeworm are released into the environment.

The mechanism of infection is more often fecal-oral, and the pathways are contact-household, food. With exogenous infection, transmission factors are dirty hands, contaminated food, with which the eggs of the pork tapeworm enter the human stomach.

In patients with teniasis (pork tapeworm), endogenous infection or autoinvasion (throwing of mature tapeworm segments from the intestine during vomiting, followed by ingestion of oncospheres or eggs) may also occur.

The susceptibility of the population is general, but the disease occurs in a small percentage of cases - up to 5%. Male and female persons get sick with the same frequency.

Infection path

A disease occurs due to the ingestion of tapeworm larvae, called the Finns or cysticercus (Cysticercus cellulosae), into the human digestive and gastrointestinal tract. They look like bubbles with scolexes (pork tapeworm heads) located inside with suction cups and hooks at the end.

Evolving, the helminth changes in size over time, increasing to 15 mm and taking a fusiform shape. Its membrane thickens and calcifies, creating a favorable environment for the existence of the parasite.

The tapeworm penetrates the human body through contact-household and food routes. The exogenous mechanism of infection is carried out by the fecal-oral method, through dirty hands and due to poor heat treatment of food.

Also, cysticercosis can also have an endogenous etiology (autoinvasion), when, during vomiting (antiperistalsis of the gastrointestinal tract), mature larvae, oncospheres or eggs of pork tapeworm are thrown into the digestive tract.

The settled helminths release the most powerful toxins into the host's body, thereby destroying healthy tissues and provoking serious organ dysfunctions. In the trophic chain, a person acts as an intermediate link (carrier) and a source of cysticercosis, releasing viable tapeworm eggs together with excrement.

The level of susceptibility to the disease is quite high and is not limited by age or gender. But even with a widespread prevalence, helminthiasis occurs only in 5% of cases.

The nature of the concentration of parasites in the brain is predominantly multiple. Most often they are localized in the meninges, the upper parts of the cerebral cortex and the free cavity of the cerebral ventricles.

In an active state, the helminth secretes a huge amount of specific secretion, causing organ edema and hydrocephalus, an excessive accumulation of cerebrospinal fluid.

Even dying, tapeworm retains its antagonistic, provoking the development of a chronic inflammatory process in the body.

The provoking factors of cysticercosis

The cause of cysticercosis of the brain, as well as of other organs, can be:

Failure to comply with the rules of personal hygiene;
Growing food in soil fertilized with infected tapeworm eggs with faeces;
Ignoring laboratory standards for analyzing contaminated feces;
Eating meat inseminated by helminth larvae;
Poorly washed and processed food;
Tactile contact with a sick person.

Pathogenic action of cysticercus in the human body

Once in the human stomach, the eggs (oncospheres) of the pork tapeworm move to the small intestine, where larvae emerge from them, penetrate into the intestinal wall, and then enter the bloodstream. With the blood stream, they are carried throughout the body and settle in various organs and tissues, where cysticercus is formed (bubbles up to 15 mm with a transparent liquid and scolex inside).

The main places of localization of cysticercus: subcutaneous fat, brain, organs of vision, muscle tissue, heart, liver, lungs, peritoneum, bone tissue. Up to 80% of lesions are in the central nervous system, in second place are the organs of vision. Ripening of cysticercus occurs within 4 months. The life span of the larva is 3-10 years.

The pathological action of the larvae is associated with:

Mechanical impact (pressure of a growing helminth on organs and tissues and, as a result, a violation of their function).
The irritating effect of the larvae on the surrounding tissue and the development of the inflammatory process is the occurrence of inflammatory and degenerative infiltrates. For example, in the brain - this is the development of meningitis, encephalitis, hydrocephalus, in the organs of vision - damage to the retina, vitreous body and others.
Toxic-allergic effect on the body due to the entry into the general bloodstream of the parasite's waste products - parasitic antigens (the development of a generalized allergic reaction, with massive death of the parasite, anaphylactic shock may develop).

What Happens During Cysticercosis

Infection with cysticercosis occurs when eggs enter the stomach, pork tapeworm oncospheres, developing in the human body in the same way as in the main intermediate host - a pig.

In the stomach, under the influence of pepsin, the oncosphere membrane is destroyed, the released six-hooked embryos are actively drilled into the intestinal wall, enter the blood vessels and hematogenously spread throughout the body, settling in various organs, where the oncospheres turn into cysticerci.

Cystic is a transparent bubble in diameter from millet grain to 1.5 cm, filled with liquid, with a scolex inside. Most often, according to many researchers, cysticercosis affects the central nervous system (74.5 - 82%), eyes and muscles.

There are two known ways of infection with cysticercosis - exogenous and endogenous. With exogenous infection, oncospheres enter from the outside. So, patients with teniasis can become infected through their own dirty hands, laboratory assistants - in cases of violation of the rules for working with the test material, as well as any person through vegetables, berries, fruits contaminated with oncospheres when fertilizing the soil of vegetable gardens and berry fields with non-neutralized sewage infested with pork tapeworm.

Only patients with teniasis are infected endogenously with antiperistalsis, the ingestion of pork tapeworm segments from the intestine into the stomach, followed by their digestion and the release of tens of thousands of eggs. In these cases, the invasion is very intense. The causes of antiperistalsis are different: any food poisoning, alcohol intoxication, recovery from the state of anesthesia, as well as the introduction of a probe, etc.

Disease types

Depending on the localization of the parasite larva in the human body, the following forms of cysticercosis are distinguished:

cysticercosis of the brain (neurocysticercosis);
cysticercosis of the eye;
spinal cysticercosis;
cysticercosis of the heart;
cysticercosis of the skin;
cysticercosis of the lungs.

Neurocysticercosis is considered the most severe form of cysticercosis.

Cysticercosis symptoms

The clinical symptoms of the disease are varied depending on the affected organ or system of the body, as well as on the severity of the infection. Allocate cysticercosis of the central nervous system (CNS), cysticercosis of the eyes, cysticercosis of muscles, skin, subcutaneous fat layer. Other forms are extremely rare. The lesion of the central nervous system accounts for about 80% of all lesions.

Cysticercosis of the central nervous system

When the central nervous system is damaged, it is customary to distinguish the following forms:

cysticercosis of the cerebral hemispheres (GM);
cysticercosis of the ventricular system;
cysticercosis of the base of the brain;
mixed cysticercosis.

With the defeat of the cerebral hemispheres of the GM, patients complain of headaches in the form of attacks, dizziness, nausea and vomiting, which does not bring relief.

All these symptoms are associated with a violation of the outflow of cerebrospinal fluid due to blockage of the ventricular formations of the brain with floating cysticercus and, as a consequence, an increase in intracranial pressure. Epileptiform seizures are one of the common symptoms.

With damage to the ventricular system, an acute onset is possible (development of hypertensive-hydrocephalic syndrome). Sudden intense headaches appear, aggravated by a change in the position of the head and body, which entails the appearance of forced postures in patients.

Headaches are accompanied by severe vomiting. Cysticercosis of the base of the brain entails a lot of symptoms with less severe complaints compared to the previous forms of the disease. Patients are worried about pain in the occipital region of the head, neck, hearing loss, dizziness, especially when turning the head, disturbances in taste.

Movement disorders from gait disturbances to paresis are possible. Some patients have sensitivity disorders and mental disorders.

The mixed form of cysticercosis is characterized by epileptiform seizures, hallucinations, mental disorders of any kind. This form is unfavorable.

Cysticercosis of the eye

In case of eye damage, patients are initially disturbed by various kinds of visual impairments, which can be aggravated up to complete blindness (the prognosis is serious, almost irreversible).

Cysticercus can be located in all membranes and structures of the eye, can cause detachment of the retina, changes in the lens.

Cysticercosis of the skin and subcutaneous fat

For a long time, it is asymptomatic, only after years you can find small rounded formations that rise above the surface of the skin, painless and soft to the touch, but later they become denser. More often located on the palms, chest, shoulders.

Often, patients develop a generalized allergic reaction such as urticaria. This form is favorable.

More rare forms of cysticercosis occur with heart damage with cardiac arrhythmias, as well as with lung damage (as an accidental finding on radiography - rounded shadows up to 1.5 cm).

In the first form, the invasion is manifested by symptoms of increased intracranial pressure due to impaired cerebrospinal fluid flow (patients complain of paroxysmal headaches, dizziness, vomiting; often they have a congested papilla of the optic nerve). Epileptic seizures are a frequent symptom.

The most common form of ventricular cysticercosis is IV ventricular cysticercosis. It is characterized by a sudden and violent onset, characterized by attacks of headaches with vomiting. Bruns attacks associated with a change in the position of the head are typical for this form of the disease.

In most patients, a forced position of the body is observed, since a change in posture causes a sharp exacerbation of headache and vomiting.

The clinic of cysticercosis of the base of the brain is also variable, manifested by a violation of cerebrospinal fluid circulation. Quite often, there is a forced position of the head, pain in the occipital-cervical region, a decrease in taste sensitivity, hearing and vestibular excitability.

Diagnosis of cysticercosis

The diagnosis of cysticercosis is made based on the following criteria:

Epidemiological history (disease with teniasis, lack of personal hygiene when eating).
Clinical data (the presence of specific patient complaints characteristic of a particular clinical form of cysticercosis).
Paraclinical research methods: in the general analysis of blood eosinophilia up to 40%, in the analysis of cerebrospinal fluid - lymphocytosis, an increase in protein.
Instrumental examination methods (electroencephalography, CT, MRI, X-ray of the lungs and other organs, ophthalmoscopy) - the presence of cavity formations with a dense membrane.
Biopsy of nodules and historical examination of materials (in particular, it is possible to examine the cavity formations of the subcutaneous fat, inside which the larva is located).
Serological blood tests to detect antibodies to pork tapeworm larvae, for the purpose of which RSK, RNGA, ELISA are used.

Differential diagnosis is carried out with tumor-like formations of the brain, echinococcosis, toxoplasmosis, neurosyphilis, phlebitis, tuberculosis of the lungs and bones, and others.

Cysticercosis treatment

Severe cases of cysticercosis (damage to the brain, eyes) are subject to hospitalization. With cysticercosis of the skin, muscles and subcutaneous fat, patients are observed on an outpatient basis.

If soft tissues are damaged by cysticercus, if they do not cause mechanical irritation and damage to the central nervous system and eyes is excluded, treatment is not carried out, the patient remains under observation. This is due to the fact that specific drugs - mebendazole (vermox) and praziquantel (azinox) cause the death of parasites, the decay products of which can cause severe allergic side reactions.

Treatment of cysticercosis of the eye and single cysticercus of the brain surgical. Additionally - etiotropic therapy with praziquantel at 50 mg / kg per day for 15 days orally while using dexamethasone at 4-16 mg per day. Etiotropic therapy with praziquantel is also performed in inoperable cases of cerebral cysticercosis.

The prognosis for cysticercosis of soft tissues, even multiple, is favorable, with lesions of the eyes and the central nervous system - unfavorable, especially with late diagnosis and the absence of the possibility of surgical treatment.

Treatment methods:

Antiparasitic therapy is prescribed with extreme caution due to the danger of the death of the parasite and the appearance of a severe allergic reaction due to the products of its decay (in particular anaphylactic shock). Therapy is carried out only in a hospital. Inoperable cases of cysticercosis of the brain, cysticercosis of the eyes are subject to treatment. The following antiparasitic drugs are prescribed: praziquantel, mebendazole, albendazole. 3 courses of therapy are recommended at 3-week intervals. Cysticercosis of the skin, PZhK and muscles in the absence of complaints is not treated, and patients are subject to dynamic observation.
Surgical methods of treatment are used in the case of accurate identification of the focus and the possibility of its removal without damaging the vital centers of the brain. In the absence of guarantees of complete recovery, therapy is supplemented with conservative treatment: the appointment of antiparasitic agents - praziquantel. glucocorticosteroids), for example, prednisolone, dexamethasone.
Symptomatic treatment complements the prescribed antiparasitic therapy (these are antihistamines - zodak, zyrtec, suprastin, pipolfen; anticonvulsants, sedatives, dehydration therapy, local therapy and others).

The prognosis of the disease depends on the form of the disease. If there is cysticercosis of the skin and muscle tissue, then the prognosis is favorable. If the patient has a lesion of internal organs and, which often occurs, the diagnosis is made late, with a far-reaching process, then the prognosis is poor.

Prevention of cysticercosis

Compliance with measures and rules of personal hygiene (timely and thorough washing of hands after visiting the toilet room and before eating, thorough processing of food products before use - fruits, vegetables, berries, and others).
Hygienic education of the younger generation, instilling in them hygienic standards of life.
Timely access to a doctor for teniasis (pork tapeworm) for the purpose of rehabilitation and dispensary observation.
Avoiding the consumption of raw, semi-raw and thermally poorly processed meat of pigs and wild boars.
Visualization of pig meat before consumption in order to identify the Finn tapeworm.
Survey of decreed population groups for teniasis (workers of meat processing plants, pig farms).
Sanitary and veterinary supervision to prevent pork contaminated with pork tapeworm from reaching the end consumer.

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