Introduction and objective:
Parasitic diseases and subsequent immunity against helminth infections involves profound changes in both the innate and adaptive immune compartments, which can have a protective effect in inflammation and autoimmunity diseases such as type 1 diabetes mellitus. The aim of the study is to evaluate the prevalence of anti-Toxocara antibodies and associated risk factors among diabetic children in a case-control study.

Material and methods:
A total of 105 blood samples from diabetic children, and 101 non-diabetic controls attending the Comprehensive Imam Ali Children’s Hospital, Alborz University of Medical Sciences in Karaj, Iran, were collected and tested by ELISA for anti-Toxocara antibodies. A questionnaire administered by direct interviews was used to collect socio-demographic information and data on associated risk factors.

Results:
The total seroprevalence of anti-Toxocara antibodies was significantly higher in healthy control individuals (5.9%) than in diabetic children (1.9%) (COR: 0.341, 95% CI: 0.079–1.480; AOR: 0.168, 95% CI: 0.029–0.967). Furthermore, seropositivity for toxocariasis was higher in the uncontrolled diabetic group than in controlled diabetic children, this was statistically significant (P = 0.046). Female participants (62.5%) were more susceptible to Toxocara infection. Also, living in rural areas (62.5%), illiteracy (75.0%), and contact with non-domesticated animals and/or soil (75.5%) were found to be the highest risk factors for toxocariasis in the studied children.

Conclusions:
The finding of the study supports the hypothesis of an association between parasitic helminths infections and diabetes mellitus, and that T1DM can be considered as a stimulus in regulating and modulating the immune system in toxocariasis. More accurate results could be obtained from a larger than necessary sample better representative of the population.