use of three Ascarid antigens in serodiagnosis of visceral larva migrans in clinically suspected patients

ABSTRACT

The syndrome of visceral larva migrans [VLM] is a zoonotic disease caused by migration of nematode larvae especially ascarids in human tissues. In the present study serum samples of 40 clinically suspected patients of VLM with persistent unexplained eosinophilia were tested by ELISA IgG and Western-immunoblotting assays for antibodies of three ascarids [Parascaris equorum, Toxocara vitulorum and Toxascaris leonina]. Embryonated egg extract antigens of these ascarids were used for serodiagnosis. By ELISA test the percentage of positivity was 42.5 percent with P.equorum, 40 percent with T.vitulorum and 30 percent with T.leonina antigens. By Western-blot assay, the seropositivity was 42.5 percent with P.equorum and 25 percent with T.vitulorum antigens. 27.5 percent of tested sera reacted with T.leonina antigen and showed single band at 65 KDa. This band was previously proven to be specific for Toxocara canis infection only. Some cases showed seropositivity for two or three species of ascarid antigens. The relationship between the seropositivity, clinical symptoms, eosinophilia and age groups was discussed. The use of two immunological assays and three types of ascarid antigens in the present study revealed for the first time the role of P.equorum and Toxocara vitulorum as causative agents of human VLM in Upper Egypt