Occupation and occurrence of respiratory infections among adults with newly diagnosed asthma.

Background: Work environments are potential areas for spreading respiratory infections. We hypothesized that certain occupations increase susceptibility to respiratory infections among adults with asthma. Our objective was to compare the occurrence of respiratory infections among different occupations in adults with newly diagnosed asthma.

Methods: We analysed a study population of 492 working-age adults with newly diagnosed asthma who were living in the geographically defined Pirkanmaa Area in Southern Finland during a population-based Finnish Environment and Asthma Study (FEAS). The determinant of interest was occupation at the time of diagnosis of asthma. We assessed potential relations between occupation and occurrence of both upper and lower respiratory tract infections during the past 12 months. The measures of effect were incidence rate ratio (IRR) and risk ratio (RR) adjusted for age, gender, and smoking habits. Professionals, clerks, and administrative personnel formed the reference group.

Results: The mean number of common colds in the study population was 1.85 (95% CI 1.70, 2.00) infections in the last 12 months. The following occupational groups showed increased risk of common colds: forestry and related workers (aIRR 2.20, 95% CI 1.15-4.23) and construction and mining (aIRR 1.67, 95% CI 1.14-2.44). The risk of lower respiratory tract infections was increased in the following groups: glass, ceramic, and mineral workers (aRR 3.82, 95% CI 2.54-5.74), fur and leather workers (aRR 2.06, 95% CI 1.01-4.20) and metal workers (aRR 1.80, 95% CI 1.04-3.10).

Conclusions: We provide evidence that the occurrence of respiratory infections is related to certain occupations.