Distribution of the tuberculin skin test results in the pulmonary tuberculosis patients and controls.

<p>Histogram of the continuous distribution of the tuberculin skin test results in the pulmonary tuberculosis patients (black bar) and controls (white bar): (A) in all included individuals, (B) in those recruited in Zhejiang Province, (C) in those in Heilongjiang Province. <b>Abbreviations:</b> TST: tuberculin skin test; PTB: pulmonary tuberculosis.