Exposure to an abundance of cat (Fel d 1) and dog (Can f 1) allergens in Swedish farming households

Background: Earlier studies have shown that farmers are to a low degree sen sitized to animal allergens. We have measured the amount of cat (Fel d 1) a nd dog (Can f 1) in farm households and examined the relationship between e xposure and sensitization to cat and dog allergens. Methods: Dust samples from the homes of 403 farmers who had participated in an epidemiologic follow-up study on respiratory symptoms were analyzed for allergen content by two-site ELISA methods. Results: Fel d 1 was detected in 99.5% of the farmers' households ranging f rom 0.055 to 1455 mu g/g dust in mattresses (GM 13.2) and to 3775 mu g/g du st in living-room carpets (GM 17.1). Can f 1 was detected in 90.6% of the h ouseholds from 0.2 to 116 mu g/g dust in mattresses (CM 2.0) and to 504 mu g/g dust in carpets (GM 4.3). Homes with pets present had the highest level s of the allergens (P<0.001). A total of 8.4% and 7.4% of the farmers were sensitized to cat and dog, respectively. A significant correlation was note d between exposure to the allergens and specific IgE to cat and dog, respec tively (P<0.001). Sensitization to cat (OR=4.9) and dog (OR=17.8) was signi ficantly associated with asthma. Conclusions: In spite of the abundance of Fel d 1 and Can f 1, farmers are only to a low degree sensitized to cats and dogs.