Respiratory diseases and allergic sensitization in swine breeders: a population-based cross-sectional study

The daily occupation as a swine breeder involves exposure to several bacterial components and organic dusts and inhalation of a large amount of allergens.

To investigate the risk of respiratory diseases and atopy in swine breeders compared with the general population living in the same area.

A population-based cross-sectional study was conducted in an agricultural area of northern Italy that enrolled a random sample of resident male breeders and non-breeders. Demographic features, comorbidities, and presence of allergic respiratory disease were retrieved through interview. Prick tests for common allergens were performed. An evaluation of pollen and mold in air samples taken inside and outside some swine confinement buildings also was performed.

One hundred one male breeders (78 native-born, mean age ± SD 43.0 ± 11.1 years) and 82 non-breeders (43.0 ± 11.1 years) were enrolled. When restricting the analysis to native-born subjects, breeders vs non-breeders showed a lower prevalence of respiratory allergy (12.8% vs 31.1%, respectively, P = .002), asthma (6.4% vs 15.8%, P = .059), rhinitis (16.7% vs 51.2%, P < .001), persistent cough (5.1% vs 15.9%, P = .028), and sensitization to grass (7.7% vs 25.6%, P = .002). There was no difference in prick test positivity, polysensitization, nasal cytologic pattern, forced expiratory volume in 1 second, and the ratio of forced expiratory volume in 1 second to forced vital capacity between breeders and non-breeders. Air concentration of molds and pollens was lower inside than outside the swine buildings investigated, particularly when the pigs were inside vs outside the buildings.

This study suggests that swine breeding does not increase, and might decrease, the risk of pollen sensitization and allergic disease.