EFFICACY. OF MASS ROENTGENOGRAPHY IN OCCUPATIONAL GROUPS

Abstract

Annual roentgenological survey in the occupational groups in Tokyo area, with the population of 44, 000, covered 84% of 262 newly diagnosed active pulmonary tuberculosis in 1971 to 1982.
Though the average annual rate of response to the survey had been more than 99% of the total population, 16% of new cases had been detected at clinics because of symptoms.
For the purpose to clarify the cause that the mass survey had failed to discover whole new cases, previous miniature films were reexamined for the 94% of total cases and compared with the status at the time of detection.
These cases were classified into two groups according to whether active lesion had been confirmed or not in the previous films.
Each group were divided into five categories by the status at the time of detection: 1. Extent is minimal by old N TA definition 2. Extent is moderate without cavitation 3. Cavitary 4. Culture positive 5. Smear positive.
In 166 cases (68%), previous films were normal and 83% of these cases had been detected at the next survery. In this group, 66 cases (40%) belonged to the categories 2 to 5. It is interpreted that 27% of newly discovered cases had been developed to the advanced type of tuberculosis within a year.
One-third of these rapidly developed cases had been found at clinics and it corresponds to 60% of total cases discovered at clinics.
Bacteriologically, 76% of total smear positive cases had been discovered at clinics and two-third of these were rapid cases which mentioned above.
The results suggest the limitation in the efficiency of the indiscriminative mass survey.