Comparison of allergic diseases, symptoms and respiratory infections between Finnish and Russian school children

Background Little is known about differences in allergic and respiratory diseases between the Finnish and Russian populations. Methods We conducted a population-based cross-sectional study to compare the occurrence of allergic diseases and respiratory infections among school children in the towns of Imatra in Finland and Svetogorsk in Russia on either side of the common border. The study population consisted of 512 Finnish and 581 Russian school children aged 7-16 years (response rate 79%). We used multiple logistic regression analysis to calculate odds ratios adjusting for age and gender. Results The prevalences of asthma (6.7 vs. 3.9%, adjusted odds ratio (OR) 1.54, 95% confidence interval (CI 0.87-2.71), allergic rhinitis (15.2 vs. 8.8%, OR 1.81, 1.22-2.68), allergic conjunctivitis (4.7 vs. 3.2%, 1.33, 0.70-2.53), and atopic dermatitis (10.5 vs. 5.9%, 1.78, 1.12-2.83) were substantially higher among school children in Imatra compared to those in Svetogorsk, but the symptoms were more severe among allergic Russian children. Tonsillitis (adjusted OR 0.11, 95% CI 0.07-0.17), sinusitis (0.39, 0.24-0.63), bronchitis (0.41, 0.27-0.62) and pneumonia (0.19, 0.04-0.90) occurred less frequently in the Finnish children, whereas otitis media (2.37, 1.55-3.62) and common cold (4.07, 3.12-5.31) were more frequent in Finland. Conclusions Allergic diseases are more common in Finnish than Russian school children, but the symptoms are more severe among allergic Russian children. Respiratory infections are in general more frequent in Russian children. "Western" lifestyle habits, differences in diagnostic procedures and environmental factors, and availability of health care and medications are discussed as possible explanations for the observed differences.