Toxocarosis hepatitis

Toxocariasis is a widespread disease and is registered in many countries.

The pathogens (the larvae of the helminth Toxocara canis and Toxocara mustax) are found mainly in children under 10 years of age. A person becomes infected by swallowing toxocara eggs. Adult individuals live in the intestines of cats and dogs, from where they are excreted into the environment with feces. The average lifespan of sexually mature individuals is 4 months, with the female T. canis laying more than 200 thousand eggs per day.

The main source of human infection are dogs. Infection occurs through direct contact with an infected animal whose fur is contaminated with eggs, or through the ingestion of soil containing toxocara eggs. Human infection is possible through eating raw or poorly cooked meat. Cockroaches eat a significant number of toxocara eggs and excrete them in a viable state.

Pathomorphology of toxocariasis hepatitis

From the eggs swallowed by a person, which get into the mouth, then into the stomach and small intestine, migrating larvae emerge, which penetrate the mucous membrane into the blood vessels and through the portal vein system get into the liver, where some of them settle, surrounded by an inflammatory membrane. In the liver tissue, the larvae cause an inflammatory granulomatous reaction, characterized by the presence of a large number of eosinophils, mononuclear cells and necrosis.

Toxocara in the liver can survive for up to 10 years, thanks to the secretion of a masking substance by the larva, which can protect the parasite from the aggression of eosinophils and host antibodies through a complex reaction that prevents their contact with the epicuticle of the larva.

Symptoms of toxocariasis hepatitis

Manifestations of toxocariasis are of little specificity. Toxocariasis usually develops acutely. Temperature appears - low in mild cases or high - up to 39 ^o C and above, sometimes with chills. Fever often recurs over several weeks and even months, while the body temperature is often subfebrile, less often - febrile. Skin rashes in the form of urticaria, sometimes Quincke's edema can be observed. Liver damage in the form of toxocariasis hepatitis is observed in 65-87% of patients. The disease is manifested by a feverish state, lung damage, hepatomegaly, eosinophilia, hypergammaglobulinemia. A biochemical blood test often shows a moderate increase in bilirubin content and a slight increase in the activity of liver enzymes.

With intensive invasion, severe granulomatous liver lesions develop, which can become chronic with repeated infections.

Diagnosis of toxocariasis hepatitis

The diagnosis is confirmed by detecting the parasite egg antigen in the blood serum using the ELISA method. Usually, ELISA is used with the secretory-excretory antigen of second-age toxocara larvae. Currently, a commercial diagnosticum is produced in Russia. An antibody titer of 1:400 or higher (in ELISA) is considered diagnostic. An antibody titer of 1:400 indicates invasion, but not disease. An antibody titer of 1:800 or higher indicates toxocariasis. Toxocara larvae may be detected in liver biopsies.

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Treatment of toxocariasis hepatitis

Diethylcarbamazine is used to treat toxocariasis hepatitis. However, this drug is effective against migrating larvae and is not effective enough against tissue forms located in liver granulomas.

Prevention of toxocariasis hepatitis

Strict adherence to hygiene measures, not allowing children into dog walking areas, and periodic deworming of cats and dogs are necessary.