Should sputum-negative presumptive TB patients be actively followed to identify missing cases in India?

Sputum smear microscopy, the primary diagnostic tool used for diagnosis of tuberculosis (TB) in India's Revised National TB Control Programme (RNTCP), has low sensitivity, resulting in a significant number of TB cases reported as sputum-negative. As the revised guidelines pose challenges in implementation, sputum-negative presumptive TB (SNPT) patients are subjected to 2 weeks of antibiotics, followed by chest X-ray (CXR), resulting in significant loss to care among these cases. To determine whether reducing delays in CXR would yield additional TB cases and reduce initial loss to follow-up for diagnosis among SNPT cases. In an ongoing intervention in five districts of Maharashtra, SNPT patients were offered upfront CXR. Of 119 male and 116 female SNPT patients with a mean age of 45 years who were tested by CXR, 32 (14%) were reported with CXR suggestive of TB. Administering upfront CXR in SNPT patients yielded twice as many additional cases, doubling the proportion of cases detected among all those tested as against administering CXR 2 weeks after smear examination. Our interventional study showed that the yield of TB cases was significantly greater when upfront CXR examination was undertaken without waiting for a 2-week antibiotic trial.