Asbestosis and tuberculosis

The frequent association between silicosis and tuberculosis has been known for a long time. However, the possible interrelationship between asbestosis and tuberculosis is not entirely clear, and some reports on the subject are contradictory. The incidence of tuberculosis was determined in three groups of people: 1) those with asbestosis, 2) those exposed to asbestos dust but without asbestosis, and 3) healthy people without pneumo-coniotic exposure. Chest X-rays of 2,846 workers surveyed in this department between 1976 and 1980 were reviewed. Since only one case of active tuberculosis was detected, residual tuberculosis was the type encountered and this was diagnosed solely on its radiological signs. The incidence of tuberculosis was: 3.87% (N = 257) for group 1; 3.45% (N = 1,215) in group 2; and 3.93% (N = 1,374) for group 3. Statistical analysis confirms the lack of significant differences in the incidence of tuberculosis in the three groups. From these findings, it is concluded that asbestosis is not an influential factor in the appearance and development of tuberculosis.