[Detection of pulmonary tuberculosis. Special characteristics of patients detected while receiving treatment for other diseases].
Tuberculosis (TB) detection is mainly classified as being either passive case-finding, at a hospital, or positive case-finding through a mass screening. Pulmonary TB patients detected while being examined for other complaints at a hospital are classified as passive findings. It is suspected that these patients have special characteristics which separate them from patients that are detected only after the onset of TB symptoms. The aim of this study is to elucidate those special characteristics of patients where detection occurred while being examined for other diseases by comparing them with patients detected by the other means. A survey was conducted on 686 pulmonary TB patients, diagnosed between 1986 and 1988, from the area served by the Kochi Prefectural Chuo Health Center, with the following results. 1) Among the 533 patients who were detected at a hospital, and excluding those detected by mass screening, 331 patients were detected only after the onset of TB symptoms (group B), with 202 patients being treated for other diseases before being diagnosed as having TB (classified as group A). In group A, 130 patients were detected because of manifesting additional symptoms related to tuberculosis such as fever and cough (group A-1), while the remaining 72 patients were detected by chance while being examined for other diseases (group A-2). 2) The number of elderly people and relapse cases was higher in group A compared to B group and the group detected by mass screening. 3) Symptoms, the rate of tubercle bacillus positives, and the period from the onset of symptoms to diagnosis (defined delay) in group A-1, were similar to group B. In group A-2, symptoms and the rate of tubercle bacillus positives were less than those of the other groups. 4) From the above findings, it is concluded that passive case-findings should be classified into 3 distinct groups.