PT  - JOURNAL ARTICLE
AU  - Katy Wong
AU  - Jing Li
AU  - Ting Fan Leung
AU  - N.S. Zhong
AU  - Gary Wong
TI  - Protective factors against childhood asthma in rural China
AID  - 10.1183/13993003.congress-2015.OA1475
DP  - 2015 Sep 01
TA  - European Respiratory Journal
PG  - OA1475
VI  - 46
IP  - suppl 59
4099  - http://erj.ersjournals.com/content/46/suppl_59/OA1475.short
4100  - http://erj.ersjournals.com/content/46/suppl_59/OA1475.full
SO  - Eur Respir J2015 Sep 01; 46
AB  - The prevalence of childhood asthma has increased significantly over the past few decades. One consistent finding of many epidemiological studies was the dramatic protection against the development of asthma in rural or farming environment. Livestock exposure and consumption of farm milk were the major factors explaining the protection in central Europe. Previous study in China revealed that the predominately agricultural environment also conferred such protection. This study aims to identify the possible factors accounting for the rural protection in China. Random samples of school children aged 5 to 7 were recruited from Hong Kong and rural China (Conghua). Conghua is a rural area in Southern China 200 kilometers north of Hong Kong. The parents completed a detailed questionnaire including the validated ISAAC core questionnaires and an environmental questionnaire to ascertain the possible environmental risk factors in rural Conghua. A total of 17,587 children (14,152 from Conghua and 3,435 from Hong Kong) were successfully recruited. In Conghua, the reported prevalence of current wheeze, current rhinoconjuntivitis, and current eczema were 1.7%, 2.7%, and 4.4% respectively. These rates were significantly (P < 0.001) lower than those in Hong Kong (7.6%, 21.7%, 8.1%). In the rural area, adjusted for confounders, logistic regression analysis revealed that keeping poultry (OR 0.79, P=0.014) and consumption of well water (OR 0.74, P=0.008) were significant factors associated with protection against current wheeze and use of asthma medication in the rural environment. Further studies including blood test and dust analysis are underway to determine how these factors may render such protection against asthma and allergies.