Prevalence of childhood asthma in Ulaanbaatar, Mongolia in 2009.

Background: Bronchial asthma is a common but important chronic disease in children in all over the world. To take measures against prevalence of childhood asthma, many researchers have surveyed the actual statuses of childhood asthma in developed countries, but in most Asia-Pacific developing countries including Mongolia such surveys have never been sufficiently conducted until now. We have thought that this survey, though performed in 2009, will give important and meaningful information even now in taking measures to prevent prevailing bronchial asthma in children in Mongolia or the countries under similar statuses.

Methods: The asthma prevalence and patient background information in Mongolian children aged 6-7 living in Ulaanbaatar were examined using a written questionnaire modified for their parents from that prepared by the International Study of Asthma and Allergies in Childhood (ISAAC).

Results: The estimated prevalence of asthma in Mongolian children was 20.9%. The following 3 risk factors were found to be related to asthma: (1) having allergic rhinitis symptoms, (2) mothers' smoking, and (3) history of severe respiratory infection before 1-year-old.

Conclusions: The asthma prevalence in Mongolian children was higher than that in the world and Asia-Pacific countries reported by ISAAC. The higher prevalence was probably attributable to households' (especially mothers) smoking in draft-free houses designed for the cold area and severe air-pollution due to rapid industrialization and urbanization in Mongolia. Smoking prohibition in the mother (including family members) and a reduction of exposure to air pollutants are urgently needed to prevent developing childhood asthma.