RELATIONSHIP BETWEEN ALLERGIC MANIFESTATIONS AND TOXOCARA SEROPOSITIVITY - A CROSS-SECTIONAL STUDY AMONG ELEMENTARY-SCHOOL-CHILDREN

Toxocara (the cause of visceral larva migrans in humans) and allergy h ave in common both elevated immunoglobulin E (IgE) levels and eosinoph ilia. In the present study, we investigated: 1) associations between T oxocara seropositivity and allergic manifestations; 2) risk factors fo r Toxocara infection; and 3) differences in Toxocara seroprevalence, a llergic manifestations and the associations between these two, in chil dren from urban and rural environments. Blood samples from 1,379 Dutch urban and rural elementary schoolchildren, were examined for Toxocara antibodies, eosinophil numbers, total IgE concentrations, and the occ urrence of inhaled allergen-specific IgE. Questionnaires investigating respiratory health and putative risk factors for infection were compl eted. It was found that 8% of the children had Toxocara antibodies, oc curring significantly less often in females than in males, The means o f total serum IgE levels and blood eosinophils were significantly high er in the Toxocara-seropositive than in the seronegative group, Allerg ic asthma/recurrent bronchitis was found in 7% of the children, allerg ic reaction on animal contact in 4%, and IgE to at least one inhaled a llergen in 16%, These variables were associated with Toxocara seroprev alence, Inhaled allergen-specific IgE and asthma/recurrent bronchitis occurred significantly less often in rural than in urban areas, and si gnificantly less often among girls than among boys, Furthermore, occur rence of allergen-specific IgE increased significantly with age, No as sociation existed between Toxocara seroprevalence and assumed risks, i .e. contact with pet animals and public playgrounds. In conclusion, ou r results indicate that allergic manifestations occur more often in To xocara-seropositive children. A relationship with an already existing allergic condition is plausible.