A Comparative Seroprevalence Study of Toxocariasis in Hypereosinophilic and Apparently Healthy Individuals

Parasitic invasion of tissues can elicit hypereosinophilia. Among helminthic infections, moderate to severe eosinophilia can be seen in toxocariasis as a pathophysiological response to a worm infection. The current study aimed to compare the rate of toxocariasis in normal and hypereosinophilic individuals in Shiraz, southern Iran. Serum samples of 100 patients with hypereosinophilia (> 10%) and 100 normal individuals (without eosinophilia) were collected. Demographic information of the participants was recorded in a predesigned questionnaire during sample collection. Anti-Toxocara antibodies in the subjects’ serum were evaluated by an ELISA. In the hypereosinophilic patients, 54 (54%) were male, and 46 (46%) were female, while in the normal individuals, 58 cases (58%) were male, and 42 (42%) were female. The differences in gender and age of the participants were insignificant (P = 0.46 and 0.59 respectively). Range of eosinophilia found in the patients was between 10-77%. Anti-Toxocara antibodies were detected in the serum of 2 (2%) of the hypereosinophilic patients and 3 (3%) of the normal individuals. No significant correlation was found between hypereosinophilia and the presence of anti-Toxocara antibodies in this study (P = 0.65). Hypereosinophilia may be due to a variety of reasons and toxocariasis is just one of these. Appropriate tests should be carried out on patients in order to rule out a Toxocara infection in hypereosinophilic individuals