The strategy of DOTS (Directly Observed Treatment Short course) has been a very successful strategy to control smear positive cases of pulmonary tuberculosis and those cases that are smear negative but have significant radiological findings suggestive of tuberculosis, However, the smear negative case of pulmonary tuberculosis which have no significant radiological findings, need to be detected and Therefore it was very crucial to detect such sputum smear negative cases for controlling tuberculosis as they contributed to "hidden burden" as they aren't being given treatment by DOTS but had pulmonary tuberculosis confirmed by culture (LJ, BacT/ALERT) or molecular techniques. The present study was a pilot project designed to assess the occurrence, if at all, of this "hidden burden" of tuberculosis in a referral DOTS tertiary care centre Safdarjung Hospital, New Delhi, India.
