Significance of the tuberculin skin test in pulmonary tuberculosis in Jamaica: comparisons of culture-positive, culture-negative and non-tuberculous patients

ABSTRACT

The results of tuberculin skin tests with PPD-S done on patients with pulmonary tuberculosis seen over a three-year period (1979-1981) were compared with the results of similar tests done during the same period in a group of persons without tuberculosis. Ninety per cent of patients with culture-positive tuberculosis had positive tuberculin skin tests, compared to 83 percent of positive tests in the non-tuberculous group. The presence of such a large proportion of positive tuberculin reactions in persons without active disease indicates that the skin test reaction cannot be used on its own to establish the diagnosis of tuberculosis in Jamaican adults. Eighty of 239 persons with a clinical diagnosis of pulmonary tuberculosis had negative sputum smears and cultures for acid-fast bacilli. Eighty-two percent of these patients had positive tuberculin skin tests. Invasive diagnostic tests and newer serological diagnostic methods are likely to increase the yield of confirmed positive cases of tuberculosis in the future (AU)