Case-finding for pulmonary tuberculosis through photofluorography and sputum examination of symptomatic persons

Abstract

To determine the best pattern for the use of radiology in tuberculosis case-finding, all registrants aged 15 and over at the Public Health Center of Ribeirão Preto, SP (Brazil) were questioned for respiratory symptoms and had a 70mm chest photofluorogram taken. This program was carried on for a year. Each symptomatic sputum specimen was examined through microscopy and culture. Each registrant with an abnormal X-ray and negative sputum specimen was submitted to clinical procedure until final diagnosis could be reached. X-rays showed abnormal shadws in 558 people. One thousand three hundred and seventy-nine people were found to have respiratory symptoms. A total 90 active cases were found; 57 of these were bacillary and 33, abacillary (5 of them asymptomatic). Of the 30,846 persons screened by X-ray, 230 (0.75%) were found to be radiologically abnormal, and 5.6%, that is, 5 out of 90, active cases. That 5 remaining, clinically inimportant, asymptomatic and abacillary cases would have been missed. A mathematical estimate of the potential danger of this type of case suggests that it is irrelevant to the well-being of a community.