Toxocariasis

Toxocariasis is a parasitic zoonotic infection caused by the larvae of Toxocara species, most commonly Toxocara canis (dog roundworm) and Toxocara cati (cat roundworm). Humans become infected by accidentally ingesting embryonated eggs from contaminated soil, unwashed vegetables, or through direct contact with infected animals. Once ingested, the larvae hatch in the intestine and migrate through various organs and tissues, causing inflammatory reactions. Toxocariasis is not a genetic disease but rather an infectious disease classified among rare conditions due to its clinical presentations. The disease manifests in several clinical forms. Visceral larva migrans (VLM) occurs when larvae migrate through major organs such as the liver, lungs, and central nervous system, causing fever, hepatomegaly, wheezing, cough, abdominal pain, and marked eosinophilia. Ocular larva migrans (OLM) involves larval migration to the eye, potentially causing decreased vision, strabismus, retinal granuloma, and endophthalmitis, which can lead to permanent visual impairment or blindness, typically affecting one eye. A covert or common form presents with milder, nonspecific symptoms including fatigue, abdominal pain, and recurrent urticaria. Neurotoxocariasis, though rare, can cause meningitis, encephalitis, or myelitis when larvae invade the central nervous system. Treatment depends on the clinical form and severity. Anthelmintic medications, primarily albendazole, are the mainstay of therapy, sometimes combined with mebendazole. Corticosteroids are frequently used as adjunctive therapy to reduce the inflammatory response, particularly in ocular and neurological disease. For OLM, ophthalmologic interventions including laser photocoagulation or vitrectomy may be necessary. Prevention focuses on regular deworming of pets, proper hygiene, and avoiding ingestion of contaminated soil, which is particularly important for young children who are at highest risk due to geophagia and play habits.

Common questions about Toxocariasis