The evolution of pulmonary tuberculosis in coal miners in Asturias, northern Spain. An attempt to reduce the rate over a 15-year period, 1971-1985.

A prospective study of 53,753 coal miners was undertaken at the Instituto Nacional de Silicosis (INS) in Asturias, Spain, during the period 1971 to 1985. This included a complete medical history, physical examination, pulmonary function tests, and intensive search for pulmonary tuberculosis. A total of 1,136 new cases of active pulmonary tuberculosis were found, all of which were confirmed by bacteriology. The average incidence was 150 +/- 31 cases per 100,000 miners year-1. Annual analysis revealed that this figure remained fairly stable during the period of study. Only a reduction of the prevalence in the subgroup of miners with massive pulmonary fibrosis was seen in later years. The risk of tuberculosis among miners was three times greater than that for the general population of the same area. Our inability to reduce the incidence of pulmonary tuberculosis in a large group of coal miners, in spite of the fact that the treatments given were effective and that in the last eight years chemoprophylaxis was given to close contacts, should be emphasized.