Toxocarosis in humans: first symptoms and treatment regimen

Toxocarosis is a type of helminthiosis, the causative agent of which is toxocar.

This helminth belongs to the type of roundworms and belongs to the genus Toksokar. This species of worms dwells mainly in the body of animals (dogs, cats, and cattle), so the development of toxocarosis in humans is a rarity.

But if the infection, nevertheless, occurs, then the larva can not develop within the human body - it almost immediately dies. For this reason, toxocariasis is not transmitted from one person to another. It is possible to infect only by contact with animals, and most often the disease affects young children.

Causative agent

The causative agent of toxocariasis can be:

canine roundworms, or Toxocara canis;
feline Toxocara, or Toxocara cati;
toksokary cows, buffalo, or Toxocara vitulorum.

Most of the cases of human infection with toxocarosis are associated with canine toxicomas. This species of helminths has a yellowish color, and can reach from 4 to 10 cm (males) or 6-18 cm (females). They have a curved caudal end and a mouth opening with 3 lips. At the head end are the so-called "side wings", which are in fact swollen cuticles. It is by its size that differential diagnostics is carried out.

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Eggs of this type of helminth have a light or dark brown hue. They have a round shape and a size that varies between 65-75 microns. Despite the fact that they are larger than the eggs of ascarids, nevertheless, they have almost the same structure. Inside the ripened toxocara egg is a larva, which is quite active and mobile. If the egg is not ripe, then it contains a blastomer of round shape. Sexually mature specimens live mainly in the stomach of young dogs or other fauna. The cycle of their life lasts 4-6 months.

For a day a mature female lays up to 200 thousand. eggs. In 1 g of stool animals contain up to 1, 00 eggs, so you can imagine how many of them are in the ground. After the eggs hit the soil, they begin to ripen. This process takes from 5 days to 1 month. Ripe eggs can survive in the soil for several months to several years.

Ways of infection with toxocariasis

Like most types of helminthiosis, toxocarosis occurs due to non-compliance with hygiene rules. If, after contact with infected animals or contaminated soil, a person neglects elementary washing of hands, then when touching the food used by the eggs, toxocar enter it, and then they enter the human body. Such a transmission path is called fecal-oral.

For the penetration of toxocar into the human body, certain conditions are necessary. To such it is possible to carry:

use of infected products and water;
contacts with dust, where the eggs are toxocar;
neglect of hygiene rules;
contact with the coat of infected animals;
use of various household items.

Sometimes toxocarosis can be infected by eating meat of infected animals. A vertical (placental) pathway of infection is also possible, when pathology is transmitted from mother to future child through the placenta, and lactational - through breast milk.

The development of the disease in humans occurs after the larvae of toxocar begin to move around the body. They can settle in:

liver;
light;
a heart;
eyes;
the brain;
skeletal musculature;
pancreas.

Parasites can be in the human body for years, while not showing themselves. With a decrease in immunity, pathology develops, but with its favorable flow, parasites themselves die.

Classification and symptoms of the disease

Toksokaroz has 3 forms:

manifest with a pronounced clinical picture;
erased when there is a blurred nonspecific symptomatology;
latent, when the disease does not manifest itself.

The severity of the course of the disease directly depends on the age category of the patient:

children under the age of 12 suffer from a manifestation of pathology having a moderate or severe severity;
in adults, the symptoms are blurred, fuzzy.

If the disease runs for 3 months, after which it passes, it is called acute. With a longer course, it is about the chronicization of the pathological process with periods of exacerbation and remission.

Forms of toxocarosis, depending on the clinical manifestations are as follows:

visceral, when various internal organs are involved in the pathological process;
eye;
skin;
neurological.

Wherever the larvae of toxocar are located, they stimulate the work of immunity, as a result of which its cells become more aggressive. Active control of parasites leads to allergic reactions, accompanied by various ailments. Among the most common forms of allergy in toxocariasis should be noted:

Epidermal rash, which in its appearance resembles mosquito bites. Eruptions can be circular and have different localization. The nature of the rash is also different: from minor discomfort to unbearable itching.
Quincke's edema is a very dangerous pathological condition, accompanied by compression of the larynx. In extremely severe cases, there is a narrowing of the laryngeal lumen (stenosis) or even the development of anaphylactic shock. With Quincke's swelling, the patient feels a sharp attack of suffocation and lack of air, breathing in and out is much more difficult. Due to the lack of oxygen blue, first a nasolabial triangle, and then all the skin. In the absence of qualified medical care, Quincke's edema almost always ends with the death of a person.
Bronchial asthma, the main symptom of which is a strong dry cough with a small amount of light mucus. Accompanying the disease attacks of poisonous (choking), caused by sudden narrowing of the lumen of the bronchi (bronchospasm). Treatment is symptomatic, aimed at removing the attack of suffocation and dilution of sputum. It is extremely difficult to cure asthma - it can only be "overgrown" or transferred to a phase of long-term remission.

In acute form or during exacerbation of chronic toxocariosis, the patient develops subfebrile or febrile fever, general weakness, increased sweating, loss of appetite. Symptoms such as body aches and muscle pain, which are invariable companions of high temperature, do not practically arise.

With exacerbation of toxocarias there is an increase in lymph nodes - lymphadenopathy. Despite this, they remain mobile and painless.

Visceral form

Almost 90% of cases of toxocarosis affects the internal organs, so the symptomatology of the disease directly depends on which of them was involved in the pathological process. But the clinical picture of body intoxication and allergies does not disappear anywhere. With the penetration of larvae toxocar into the liver, other organs of the digestive tract are affected.

After that, the larvae penetrate into the bile ducts and ducts of the pancreas, then into the small intestine and PDC. Due to this, there is a violation of the outflow of bile and juice from the prostate, thus injuring the intestinal wall. This process is accompanied by:

severity and discomfort in the right hypochondrium;
abdominal swelling;
meteorisms;
stitching pain in the right hypochondrium;
bitterness in the mouth;
violation of the stool, when the constipation is replaced by diarrhea;
bouts of nausea after eating;
abdominal pain;
sharp weight loss.

Toksokary is able to break the integrity of the intestinal wall, which leads to constant blood loss. Although it is small, but with systematic bleeding, anemia develops. Accompanied by anemia weakness, headaches and dizziness, pale skin, trembling in the limbs, noise in the ears. In the severe course of the pathology, short-term syncope (fainting) is possible.

When the respiratory system is affected, the following symptoms occur:

persistent unproductive cough with absence or minimal amount of sputum;
dyspnea;
elongation and difficulty of exhalation;
Attacks of suffocation.

With the ignoring of symptoms, toxocarosis leads to the development of bronchial asthma. Sometimes the disease can cause pneumonia, pulmonary edema.

In severe cases, the larvae penetrate the heart and settle on its valves, which causes the development of endocarditis. Clinical manifestations of the pathological process are:

constant weakness;
blueing of the fingers and nasolabial triangle;
when the left side of the heart is affected, the patient develops a cough and shortness of breath, especially when lying down;
the formation of symmetrical swelling of the tissues of the legs; when the right side of the heart is affected, the stomach also swells.

Eye shape (ophthalmotoxocarosis)

The eye form of toxocarias is much less common visceral. As in most cases, the cause of the development of pathology is weak immunity, which is unable to prevent the larvae from entering the eyes. As a rule, the disease affects only one visual organ. When it enters the larvae, granulomas form in the lens or retina.

Ocular toxocarosis leads to the development of a chronic inflammatory process. On its soil keratitis (inflammation of the cornea), endophthalmitis (purulent inflammation of the ocular membranes), retinal detachment or optic neuritis often develop. In severe cases, it is possible to develop complete blindness.

Neurological form

When the larvae infect the toxocar of the brain, a neurological form of toxocarosis develops. This affects the membrane and tissues of the GM, as well as the central nervous system. A person begins to experience difficulties with thinking, object recognition, and motor skills.

The clinical picture of the neurological form of toxocarias consists of the following symptoms:

seizures, similar to an attack of epilepsy;
syncope;
disorders of consciousness;
changes in gait;
imbalance;
photophobia;
intolerance to loud sounds;
sharp reaction to touch;
intense pulsating or pressing headache;
nausea with bouts of vomiting;
hypotonic muscle (up to complete cessation and functioning and absolute immobilization);
causeless aggression, affective states;
It is impossible to cope with a stressful situation on your own.

In rare cases, it is possible to develop a combined toxocarosis, when a person suffers from several forms of pathology at once. However, science has few cases of such a deviation.

Skin Form

For the dermal form of toxocarosis is characterized by the development of an allergic reaction accompanied by epidermal eruptions of varying intensity and localization. A person has severe itching, hyperemia and swelling.

Symptoms can occur in one place, then move to another part of the body. This is due to the peculiarity of the movement of larvae along the body.

Diagnostics

A preliminary diagnosis is made by a doctor based on several factors. They are:

anamnesis collection;
presence of pronounced symptoms of pathology;
eosinophilia.

However, the final diagnosis is made only based on the results of the biopsy. If a biopsy specimen reveals larvae of toxocar, treatment can begin.

Quite good results are given by serological tests that determine the presence and level in the blood of antibodies to toxocar antigens. Especially effective is the ELISA method, whose accuracy is 95%. If the antibody titers are in the range 1: 200-1: 400, this indicates the presence of parasitic invasion. At antibodies titer in 1: 800 it is possible to speak about development of high-grade disease. Such research results indicate the need for therapy. The development of a treatment regimen is individual for each person, but with special care and responsibility approach to choosing a method of treatment for young children.

Since toxocarans do not live in the intestine, it is impossible to detect their larvae in the stool. Therefore, the analysis of stool is impractical. It is also impossible to track the movements of the larvae in the body, but you can pay attention to the symptoms of parasitic invasion, because the human immune system does not ignore such a deviation. For this reason, in the diagnosis of toxocarias, immunological tests are mandatory.

If the ophthalmic form of the disease is suspected, an eye examination with an ophthalmologist is mandatory. In this case, it is impossible to rely on eosinophilia, since an increase in the level of eosinophils in the blood for this type of toxocarias is insignificant. The same goes for immunological tests.

It should also take into account the fact that not always the results of serological studies and a pronounced clinical picture may indicate the presence of toxocars in the body. Positive test results may well speak of the development of other types of helminthiosis, and negative results indicate another localization of toxocars and a small number of them.

How to treat toxocariasis?

The specific scheme of therapy for toxocarias does not exist, but it is impossible to prevent the situation from happening. Infectionists often prescribe the following medications:

Vermox is an anthelmintic agent, the active substance of which is mebendazole. Dosage is 100 mg twice a day for 2 to 4 weeks. The drug is safe, but in rare cases, there may be side effects such as nausea and cephalalgia.
Mintezol - a drug based on tiabendazole, the dosage of which is calculated by the scheme of 50 mg per kg of body weight once a day. Applied for the treatment of toxocarias for 5-10 days. The medication can cause side effects, but they pass pretty quickly.
Ditrazine citrate, the active ingredient of which is diethylcarbamazine. The course of treatment is from 14 to 28 days for 4 or 6 mg per 1 kg of weight per day. The dose is calculated individually. The drug may cause pronounced symptoms of side effects and overdose. They are manifested through the occurrence of fever, attacks of nausea, cephalgia, vertigo.
Nemozol is an antihelminthic drug, the active ingredient of which is albendazole. Assign 10 mg per kilogram of weight 1 time per day for 10-20 days. Rarely, the patient has side effects in the form of stool, nausea, headache. The drug has a teratogenic effect, so its use in pregnancy is not practiced.

Treatment of toxocarias in adults is mainly outpatient. Only with the development of serious complications is the patient shown immediate hospitalization in the hospital. At the beginning of the death of larvae toxocar immune system produces an acute reaction, manifested in the form of allergies. For this reason, in parallel with antiparasitic drugs necessarily prescribed and antihistamines. Throughout the course of therapy, the patient should follow a diet that excludes brightly colored vegetables and fruits, wine, cheese and spices.

Toksokaroz requires an integrated approach to therapy, therefore, along with antiparasitic and antihistamine drugs, the patient is prescribed other medications. They will help improve the general condition of the person, and also contribute to the speedy recovery of the body after the illness.

The auxiliary methods of therapy include:

etiotropic;
pathogenetic;
symptomatic.

Let's briefly review each therapeutic approach separately.

Etiotropic therapy

Etiotropic therapy involves the use of drugs aimed at eliminating the cause of the disease. That is, the complete destruction of larvae toxocar. Often used drugs:

Mebendazole is an anthelmintic preparation that is approved for adults and children over 2 years of age.
Albendazole is another antihelminthic agent used to treat various types of helminthiasis. The medicine is prescribed for children from 1 year of age and adult patients.

Dosage is calculated individually for each patient. Since many antiparasitic drugs have a number of serious side effects, it is better to refuse self-medication in this case.

Pathogenetic therapy

Pathogenetic treatment is aimed at restoring the normal functioning of the body, which was disturbed by the disease. In this case, drugs are also used that stop pathological processes and prevent their possible complications. For this purpose, apply:

Hormonal preparations (glucocorticoids): Prednisolone, Dexamethasone. They have a powerful anti-inflammatory effect, and also stop allergic reactions caused by parasitic invasion.
Solutions of electrolytes, intended for intravenous administration in severe current toxocariasis. They eliminate the intoxication of the body and facilitate the general condition of the patient. In this case, it is advisable to use solutions of sodium chloride, potassium chloride, sodium acetate.
Lacto- and bifidobacteria, aimed at restoring intestinal microflora and preventing intestinal dysbiosis. Appointed with a visceral form of toxocariasis.
Adsorbents used to remove toxins from the body: Smecta, Enterol.

Symptomatic therapy

Such treatment is aimed at eliminating the symptoms associated with toxocarosis: high fever, nausea, vomiting, etc.

Antipyretics stop heat and stop muscle pain: Ibuprofen, Nurofen, Paracetamol.
Spasmolytics stop vomiting and adjust the work of the digestive tract: Papaverin, Drotaverin.
Antiemetic drugs: Cerucal, Metoclopramide.
Antihistamine, cupping manifestations of an allergic reaction: Tsetrin, Loratadin, Fenkarol, Tavegil, and others.

Treatment of toxocarias has its own effectiveness criteria, which are:

the removal of the clinical picture of toxocariasis - both specific and nonspecific symptoms;
decrease in the level of eosinophils;
decrease in the level of antigens to toxocariasis to 1: 8000 and less.

The duration and therapeutic number of courses depends on the positive dynamics of the treatment. In most cases, toxocarosis is quite successfully treated, but in extremely rare and severe cases, a lethal outcome is possible.

Consequences and myth of the effectiveness of self-treatment

Basically, the disease does not cause serious complications, but in the absence of adequate treatment can develop:

trauma of tissues of different severity;
secondary inflammatory processes;
hemorrhage;
tissue necrosis.

When lesions of larvae toxocar eyes, it is possible to develop one-sided blindness. In addition, with the long absence of therapy, granulomas can form in the tissues of various internal organs.

With regard to the effectiveness of folk remedies used for toxocarosis, this therapy can only temporarily eliminate the symptoms of the disease. To cure it completely without the use of anthelmintic drugs is impossible, so the methods of alternative medicine can be used only in combination with pharmacy medicines.

Prevention

To avoid the development of toxocarias, which requires long and exhausting treatment, all efforts should be directed to preventive measures. To do this, you should:

carefully observe the hygiene of the hands, especially after visiting the restroom and contacting animals;
to teach children hygiene from early childhood;
conduct regular preventive procedures aimed at preventing helminthiasis in domestic animals;
carefully wash fruits and vegetables, you can with household soap;
make sure that the meat products undergo a complete heat treatment.

It is important to comply with these rules for people at risk of toxocariasis. Such persons are:

Little children who like to play with sand and soil;
owners of domestic animals, in particular dogs and cats;
gardeners and truck farmers;
veterinarians.

When the first symptoms of toxocarias occur, you should immediately consult a doctor and take the necessary tests. Refusing self-treatment, a person can be fully confident that he will not harm his own health, and this is most important when treating not only helminthiases, but also any other, even the easiest, diseases.