Infectious Diseases and Microbiology - Toxocariasis / Visceral Larva Migrans (Toxocara canis and Toxocara cati )

Infectious Diseases and Microbiology - Toxocariasis / Visceral Larva Migrans (Toxocara canis and Toxocara cati ) 
Toxocariasis, also known as Visceral Larva Migrans
Toxocara canis and Toxocara cati are both species of Nematode, which are a type of roundworm.
The tissue manifestations are referred to as Visceral larva migrans.
Humans are terminal hosts. Dogs (T canis) and cats (T cati) serve as decisive hosts. Dogs and cats excrete Toxocara eggs in their feces. Humans, particularly youngsters aged 1-4 with a background of pica, acquire the infection by consuming eggs.

A significant number of persons are without symptoms. The symptoms of larval infestation might vary depending on their location. Some individuals may have gastrointestinal pain, rash, fever, enlarged liver, retinal involvement resulting in blindness, or manifestations affecting the heart, respiratory system, or central nervous system.

Upon ingestion, eggs give rise to larvae that then move to various organs, such as the lungs, liver, kidney, heart, eyes, muscle, and central nervous system (CNS). The larvae undergo encystation, transforming into second-stage larvae. The larvae migration results in the formation of tracts characterized by hemorrhagic necrosis, as well as infiltration of eosinophils and lymphocytes. Granulomas can form around deteriorating larvae. The development of the disease is caused by the intensity of the inflammation and the specific site and quantity of the deceased larvae.

Elevated levels of hypereosinophilia and hypergammaglobulinemia, along with increased titers of isohemagglutinin against the A and B blood group antigens, are indicative of a probable infection. The diagnostic process entails serologic testing, analysis of tissue biopsies for larvae, and evaluation of clinical signs and symptoms. Stool samples can be analyzed to detect eggs in pets.

Mebendazole and albendazole are utilized for therapeutic purposes. Prevention entails the practice of deworming pets and maintaining proper hygiene for pets.

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