Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 5 2 2013 06 15 132 135 EN Abdullah Karimi Pediatric Infections Disease Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Koroush Fakhimi-Derakhshan School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Farid Imanzadeh Departments of Pediatric Gastroenterology, Mofid Children’s Hospital, Shahid Beheshti University of Medical Sciences, Iran. Mohamad Rezaei School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Zahra Cavoshzadeh Pediatric Infections Disease Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Saeid Maham Pediatric Infections Disease Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2015 10 16 Objective: Childhood infectious diseases are one of the most known environmental pathogenic causes of childhood asthma. The high prevalence of both Helicobacter pylori infection and asthma in our country prompted us to assess anyprobable as- sociation between them in childhood. Methods: This cross-sectional study recruited 196 children aged 6 to 12 years old comprising 98 asthmatic (case group) and 98 healthy (control group) individuals. Urea breath test was performed for all of the children and H. pylori infection was compared between the two groups according to the urea breath test results. Results: Urea breath test was positive in 18 asthmatic (18.36) and 23 (23.36) healthy subjects but was not significantly dif- ferent between the case and controls (p = 0.380). Further analysis in the asthmatic group revealed association of H. pylori- infection with age (p < 0.001) and duration of asthma (p = 0.010). However, no significant correlation was found between sex, severity of asthma, controled asthma  or abnormal pulmonary function tests with H. pyloriinfection (p = 0.804, 0.512,0.854 and 0.292, respectively). Conclusion: Given the results of the study, H. pylori infection was not significantly differentbetween asthmatic and healthy children. In asthmatic patients, there was no significant association between H. pylori infection and sex, severity of disease, control status of disease andnormal or abnormal pulmonary function tests. H. Pylori infection had a significant association with increasing age and duration of asthma. https://ijm.tums.ac.ir/index.php/ijm/article/view/620 https://ijm.tums.ac.ir/index.php/ijm/article/download/620/393