Lung tuberculosis morbidity among workers in medium and small plants

Abstract

During the years 1955, 1956, and 1957, morbidities of pulmonary tuberculosis among totally 12, 086 workers in medium and small plants from Ashikaga district, Tochigi prefecture, were surveyed.
1. The number of patients with pulmonary tuberculosis per 100 decreased from 3.1 to 1.7 during the period of 1955-1957. This improvement which was better than that of the estimated rate for nationwide industrial workers in Japan might be ascribed chiefly to strictly enforced health examinations and partly to the regional specificity.
2. The peak of age specific morbidity rate shifted from the middle age to the older group during this period.
3. In spinning mills, when they were observed by the size of enterprise, the rate of those who had been under supervision without specific treatment was twice, and of those requiring rest and medical treatment was 2.5∼5 times higher in small plants compared to the medium. The rate of cases with far advanced, caseous and bilateral lesions were also higher in small plants. The rate of cases with exsudative lesions showed a tendency toward the decrease in medium plants while in small plants it inclined to the increase, amounting twice as high as the former by 1957.