Toxocara is a genus of parasitic worms belonging to the phylum Nematoda, specifically the order Ascaridida and the family Toxocaridae. This genus comprises several species of roundworms, most notably Toxocara canis and Toxocara cati, which are common intestinal parasites of various mammals.
Toxocara worms have a complex life cycle involving a definitive host and a paratenic host. In the case of Toxocara canis, the definitive host is typically dogs, while for Toxocara cati, it is cats. Adult worms reside in the small intestines of these hosts, where they lay eggs that are then passed out through the feces.
The eggs of Toxocara are highly resistant to environmental conditions and can survive for long periods in soil. When a suitable host ingests these eggs, usually through contaminated food or water, the eggs hatch in the intestines, releasing larvae that penetrate the intestinal walls. From there, they migrate through various organs and tissues, causing damage and inflammation.
Toxocara larvae can also infect humans, especially children, who accidentally ingest contaminated soil or poorly cooked meat. Once inside a human host, the larvae continue their migration, causing a condition known as visceral larva migrans (VLM), characterized by fever, hepatomegaly (enlarged liver), and pneumonitis (lung inflammation).
Prevention of Toxocara infections includes proper hygiene practices, such as handwashing after being in contact with soil or animals, and regular deworming of pets.
