Toxocariasis - causes and symptoms of toxocariasis

Modern medicine distinguishes four main types. The first type is visceral, in which parasites affect the internal organs. It is caused by the penetration of a large number of toxocara into the body. Most often, this type of disease affects children from 1.5 to 4 years old (mostly boys). The second type is ocular, in which the larvae migrate to the eyes and periorbital space. With cutaneous toxocariasis, the skin is affected, and with neuralgic toxocariasis, parts of the central nervous system are affected.

Previously, the imaginal form was also considered, implying the transformation of the parasite in the human intestine into adults. However, such cases have not been confirmed, and at the moment, doctors tend not to distinguish the imaginal form in humans.

Causes

The main carriers are domestic animals, especially dogs.

The main conditions for infection include contact with the fur of infected animals, drinking water contaminated with parasitic eggs, using poorly washed vegetables and fruits, contact with soil contaminated with parasite eggs, and failure to comply with hygiene rules.

A risk group is also determined that is most susceptible to infection: small children (from 1.5 to 5 years old) who actively come into contact with sand and soil during games, veterinarians, workers in pet nurseries, dog breeders, vegetable and fruit sellers (frequent contact with dirty products that contain fragments of soil with a possible pathogen), any activity that involves frequent and long contact with land.

The disease is widespread and is registered in many countries. The average prevalence of intestinal form in dogs examined on different continents is over 15%, but in some regions it reaches 93%. According to seroepidemiological studies, from 2 to 14% of examined healthy individuals in various foci of the disease have positive immunological reactions to the detection of this formation.

Symptoms

Each type of disease is characterized by its own specific signs.

Visceral type manifestations:

• high temperature;
• fever;
• increased number of eosinophils and immunoglobulins in the bloodstream;
• enlarged liver;
• lymphadenitis;
• dry cough with attacks at night;
• shortness of breath;
• inhalation with aspiration;
• abdominal pain, bloating;
• nausea;
• diarrhea, vomiting (less common).

Signs of the ocular variety:

• inflammatory process in the cornea (keratitis);
• whitish glow in the lumen of the pupil (leukocoria);
• inflammation of the optic nerve;
• combined suppuration of the vascular and iris of the eye (uveitis);
• purulent inflammatory processes inside the eyeball (endophthalmitis);
• nodular formation in the eye (granuloma);
• inflammation of the vitreous cavity (parsplanitis);
• abscess;
• fixation of larvae directly in the vitreous body of the eye;
• impaired visual perception;
• strabismus (sometimes).

Diagnostics

This disease is considered a severe parasitic disease, which is fraught with the formation of many different complications (pancreatitis, kidney damage, myocarditis, necrosis, pneumonia, visual impairment up to one-sided blindness). Therefore, if you suspect it, you must make an appointment with a general practitioner (for adults) or a pediatrician (for children) as soon as possible. The doctor will be able to prescribe the necessary primary tests to establish an accurate diagnosis and refer you to a specialist.

Thus, in the case of the eye type, a consultation with an ophthalmologist is required, and in the case of the skin type, a dermatologist.

The disease can be diagnosed by the following methods: immunofluorescence reaction (IFA) and enzyme-labeled bodies (EMA), enzyme-linked immunosorbent assay (ELISA), biopsy, ophthalmological examinations, blood tests for elevated eosinophils.

Treatment

Therapeutic measures have not been fully developed to date. To draw up a final treatment plan, a consultation with an infectious disease specialist-parasitologist is absolutely necessary.

The following are used in therapy:

• antinematode and anti-inflammatory drugs;
• corticosteroid hormones (for ocular);
• if there is a small number of parasites infected and the disease is mild, specialized drugs are not used, and general tonics are prescribed.

Prevention

The only way to prevent re-invasion is to prevent the parasite eggs from entering the body. To do this, you should adhere to certain rules: observe hygiene rules, eat only well-washed food, conduct timely preventive examinations of dogs and cats, create special areas for walking pets, and control the number of stray dogs.