Frequency of anti toxocara antibodies in schoolchildren with chronic cough and eosinophilia in urban and rural area of Ahvaz, Iran in 2006

It has been suggested that chronic cough may be atributed to toxocariasis. There are few epidemiological studies carried out on this subject in Iran. The aim of this study was to determine the frequency of anti-toxocara antibodies in children with chronic cough.Subjects and In a cross sectional study during a tuberculin survey in Ahvaz, a city in southwest Iran a total of 4206 children selected by randomized two-stage cluster sampling. Children with chronic cough were investigated for toxocariasis. Initially, the absolute eosinophil count was determined. Next, children with eosinophilia (>500/mm3) and hypereosinophilia (>1000/mm3) were tested for toxocara-IgG - ELISA kit (Ibl, Hamburg). Other epidemiological data collected by a questionnaire and analyzed with 95% confidence interval using SPSS 11.5 software. Of total 115 children with chronic cough, 29 (25.2%) were eosinophilic, among them 34.5% were hypereosinophilic, 16 (13.9%) were ELISA-IgG positive for T. canis. No correlation between intestinal parasites and toxocariasis was detected (P>0.05).There was also no significant age, gender, and living site difference in toxocara antibody frequency (P>0.05). Anti toxocara antibody was detected in more than half of children with chronic cough. Intestinal parasites are not associated with hypereosinophilia and show no cross reacting to toxocara antibody.