Toxocaridae

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Toxocaridae
Kingdom:	Animalia
Phylum:	Nematoda
Class:	Secernentea
Order:	Ascaridida
Family:	Toxocaridae

Toxocaridae is a family of parasitic nematodes within the order Ascaridida. Members of this family are known to infect a variety of hosts, including mammals and birds, and are of significant medical and veterinary importance due to their zoonotic potential. The most well-known genera within this family are Toxocara and Toxascaris.

Morphology

Toxocaridae are characterized by their elongated, cylindrical bodies typical of nematodes. They possess a complete digestive system with a distinct mouth, esophagus, and intestine. The anterior end of these nematodes is equipped with three prominent lips, which are used for attachment to the host's intestinal wall. The size of these worms can vary significantly, with some species reaching lengths of up to 18 cm.

Life Cycle

The life cycle of Toxocaridae involves both definitive and intermediate hosts. The adult worms reside in the intestines of the definitive host, where they reproduce sexually. Eggs are excreted in the host's feces and require a period of development in the environment before becoming infective. Upon ingestion by a suitable host, the larvae hatch and migrate through various tissues before maturing into adults in the intestines.

Toxocara canis

Toxocara canis is a common parasite of dogs and other canids. The life cycle includes a migratory phase where larvae can cause visceral larva migrans in humans, a condition resulting from the larvae migrating through human tissues.

Toxocara cati

Toxocara cati primarily infects cats. Similar to T. canis, it can cause ocular larva migrans in humans, leading to visual impairment if larvae migrate to the eye.

Pathogenesis

Infections with Toxocaridae can lead to a range of clinical manifestations depending on the host and the species involved. In definitive hosts, heavy worm burdens can cause gastrointestinal disturbances, malnutrition, and growth retardation. In humans, accidental ingestion of infective eggs can lead to larval migration, causing toxocariasis.

Diagnosis

Diagnosis of Toxocaridae infections typically involves the identification of eggs in fecal samples using microscopic examination. Serological tests can also be used to detect antibodies against Toxocara antigens in humans suspected of having toxocariasis.

Treatment and Control

Treatment of Toxocaridae infections in animals often involves the use of anthelmintic drugs such as fenbendazole and ivermectin. Control measures include regular deworming of pets, proper disposal of animal feces, and public education to prevent accidental ingestion of infective eggs.

Public Health Implications

Toxocaridae, particularly Toxocara species, pose a significant public health risk due to their zoonotic potential. Human infections can lead to serious health issues, emphasizing the importance of preventive measures and awareness.

Also see

• Nematoda
• Ascaridida
• Zoonosis
• Parasitic diseases