Prevalence and risk factors of chronic respiratory disease in a farming population

Summary. An epidemiological survey on the prevalence of respiratory diseases was conducted in the province of Cremona (Italy). Methods: a population of 2.932 farmers (response rate 90.9%) was examined. As a control group was randomly selected a sample of 290 non-rural people who lived in the same area. A standardized questionnaire for the collection of respiratory symptoms and the analysis of the risk factors for the respiratory system was administered to both groups, together with chest x-ray and pulmonary function test (FVC and FEV1). After the initial screening, the study of CO diffusion capacity, allergic skin tests, using common allergens and serum precipitin test was performed. Results: the prevalence of chronic bronchitis was significantly higher among farmers than in the control group (9.9% vs 4.8%). The prevalence of Hypersensitivity Pneumonitis (HP=Farmer's lung) was 1.4%, no HP case was demonstrated in the control group. The prevalence of bronchial asthma did not differ between the two groups: 2.8 and 2.4% respectively, but FEV1 values were lower between farmers. The risk of chronic respiratory disease was high only in farmers working on small farms and stables with traditional housing.