Serologic diagnosis of Toxocara canis infection

Visceral larval migrans (VLM) caused by Toxocara canis presents a wide spectrum of clinical manifestations with eosinophilia. Although the presence of increased serum IgE and isohemagglutinin titers are useful screening tests, the specific diagnosis rests on identification of larvae in biopsy specimens of tissues or serologic tests for specific antibody to the Toxocara organism. A 2-year-old boy with marked eosinophilia associated with milk respiratory tract illness had negative indirect hemagglutination (IHA) and bentonite flocculation (BF) titers to Toxocara, but serum tested for specific antibodies against Toxocara embryonated egg (TEE) antigens by the Ouchterlony immunodiffusion and enzyme-linked immunosorbent assay (ELISA) technics was strongly positive.