Designing and standardizing Toxocara serologic diagnostic kit and determining anti-Toxocara antibodies frequency in patients referred to health care centers in Urmia (northwest of Iran)

Toxocariasis is a helminthic zoonosis caused by larval stages of the roundworm of dog, Toxocara canis, and less frequently by T. cati, the roundworm of cats. Eosinophilia in peripheral blood may be indicative of a disease; however, it does not necessarily represent toxocariasis. Therefore, it is necessary to investigate the relationship between eosinophilia and toxocariasis in a region. The aims of this study were the diagnosis of hyperosinophilia patients using traditional ELISA kit and also by a handmade ELISA kit produced by T. canis excretory-secretory (TCES) antigens as well as the determination of the abundance of anti-Toxocara antibodies among people referred to Urmia, northwest of Iran care centers. Traditional ELISA kit was used to determine anti-TCES-specific IgG antibodies on 180 hypereosinophilic samples. These antibodies were evaluated in 1002 samples, including 180 hypereosinophilic samples and 822 random samples without eosinophilia by a handmade ELISA kit produced by TCES antigens. A Western-blot confirmatory test was performed on ELISA-positive samples. Our results showed a 17.22% prevalence rate of Toxocara antibodies among hypereosinophilic samples with traditional ELISA kit, and this rate was 3.89% in the 1002 study population with random sampling (with or without eosinophilia). Also, there was a good match between the results of handmade ELISA with those of traditional kit. The positive results in the ELISA method were confirmed by the Western-blot analysis. Our findings show that although the high eosinophil count is not necessarily a sign of toxocariasis, in Urmia distric, about one-fifth of eosinophilia cases have anti-toxocariasis antibodies. In addition, the abundance of anti-Toxocara antibodies in this area was 3.89%.