Risk factors associated with allergic sensitization and asthma phenotypes among poultry farm workers

Background: This study investigated the risk factors for occupational allergic sensitization and various asthma phenotypes in poultry-workers. Methods: A cross-sectional study of 230 workers used a modified ECRHS questionnaire, spirometry, FeNO, Phadiatop, and sIgE to poultry farming related allergens. Results: Worker's mean age was 37 ± 9 years, 68% male, 43% current-smokers, 34% atopic, and 5% casual-workers. The prevalence of non-atopic asthma (NAA = 7%) was higher than atopic-asthma (AA = 5%) and probable allergic occupational-asthma (OA = 3%). Sensitization to at least one poultry farming related allergen was 24%. Workers sensitized to chicken-specific-allergens were more likely to be atopic (OR_unadj = 20.9, 95%CI: 4.7-93.2) or employed as casual-workers (OR_unadj = 6.0, 95%CI: 1.1-35.9). Work-related chest symptoms were associated the rearing-department (OR_adj = 3.2, 95%CI: 1.2-8.4) and exposure to high gas/dust/fumes (OR_adj = 4.8, 95%CI: 2.4-9.5). Airflow reversibility (OR_adj = 10.9, 95%CI: 2.0-60.3) was significantly associated with casual-work status. Conclusion: Allergic and non-allergic mechanisms play a role in asthma development among poultry-workers with casual workers demonstrating increased risk.