Occupational and environmental risk factors for idiopathic pulmonary fibrosis in Egypt: a multicenter case-control study.

BACKGROUND Despite the advances in medical therapy and technology, the prognosis of idiopathic pulmonary fibrosis (IPF) remains poor and the need for disease prevention based on identifying the risk factors becomes mandatory. Occupational and environmental exposures were studied in several countries and found to play important role in the disease development. However, in Egypt, a little attention has been paid to study the effect of these factors in the disease development. OBJECTIVE To identify the occupational and environmental risk factors associated with the development of IPF in Egypt. METHODS A multicenter hospital-based case-control study was carried out in chest hospitals affiliated to three Egyptian cities-Cairo, Tanta and Mansoura. Subjects were 201 patients with confirmed IPF (cases) and 205 age-, sex- and residence-matched controls. Data on occupational and environmental factors were obtained from a questionnaire. Multiple logistic regression analysis was used to determine the independent risk factors of IPF in both sexes for single factors with adjustment for age, residence and smoking status. RESULTS Compared with the controls, the risk of IPF in male workers was observed to increase significantly in chemical and petrochemical industries and carpentry and wood working (OR = 2.56, 95% CI: 1.02-7.01), and with occupational exposures to wood dust and wood preservatives. Among female workers, a significant increase was observed in farming (OR = 3.34, 95% CI: 1.17-10.12), raising birds and occupational exposures to animal feeds, products and dusts and pesticides. Risk of IPF decreased significantly in male workers and insignificantly among female workers in sales and clerical related activities. The environmental exposures to birds and cats were significantly associated with elevated risk of IPF development in both sexes. CONCLUSION In Egypt, farming, raising birds and wood working are important risk factors for the development of IPF.