TOXOCARIASIS, A MAJOR HELMINTHIC ZOONOSIS

Toxocariasis is a zoonosis due to the migration of Toxocara sp. larvae into mammal - including human - organism. The high prevalence of the parasite in pets regularly elicits the contamination of the environmen t by Toxocara sp. eggs. Human beings become infected by ingestion eith er embryonated eggs from soil (geophagic behaviour), hands or vegetabl es, or sometimes larvae from undercooked giblets. Diagnosis relies upo n sensitive immunological method (ELISA and Western-blot) that use Tox ocara larval excretory-secretory antigens. Seroprevalence is high in d eveloped countries, especially in rural areas. In some tropical island s, seroprevalence rates higher than 85 % have been reported. The disea se comprises three syndromes: visceral larva migrans, ocular toxocaras is and an entity associating chronic weakness, allergic symptoms, abdo minal pain and mild hypereosinophilia. Atopic status boosts the sympto ms. Therapy of larva migrans and ocular toxocariasis is primarily base d upon corticosteroids use. Other forms require prevention of recontam inations, sanitary education and sometimes treatment with anthelminthi cs (diethylcarbamazine).