Having lived on a farm and protection against allergic diseases in Australia

Background Farmers' children in northern Europe have a lower prevalence of atopy, hay fever and asthma than other children. Farms in Australia differ in scale and operation from those in Europe and the prevalence of allergic diseases in children is higher. Objective To investigate whether having lived on a farm as a child in Austr alia is associated with a lower risk of allergic diseases. Methods Cross-sectional study of children (n = 1500) aged 7-12 years from t wo rural towns: Wagga Wagga in a mixed farming region, and Moree in a crop farming region. Parents answered a questionnaire and children had a skin pr ick test for atopy. Results Twenty percent of children had lived on a farm for at least 1 year. The effect of having lived on a farm differed between the towns (P < 0.001 ). It was associated with a lower risk of atopy in Wagga (adjusted odds rat io (aOR) 0.47, 95% confidence interval (CI) 0.32-0.72) but not in Moree (aO R 0.97, 95% CI 0.62-1.53). Children from Wagga were more likely to have liv ed on a livestock farm than children from Moree (26.1% vs. 9.1%, 95% CI for the difference 8.9-25.4). Conclusion Having lived on a farm in Australia can confer protection agains t atopy in children. Further studies are needed to identify possible protec tive mechanisms associated with farm animals or to establish whether the pr otective effect is explained by other related exposures.