Ambulatory Gastric Lavages Provide Better Yields of Mycobacterium tuberculosis Than Induced Sputum in Children With Intrathoracic Tuberculosis

To compare mycobacterial yield by induced sputum (IS) and gastric lavage (GL), performed on an ambulatory basis in children with probable intrathoracic tuberculosis. Diagnostic accuracy study. Two tertiary care hospitals in Delhi, India. Children aged 6 months to 15 years with newly diagnosed intrathoracic tuberculosis. GL and IS were performed in children on 2 consecutive days on ambulatory basis. Samples were examined by Ziehl-Neelsen staining and cultured on an automated BACTEC-MGIT 960 system. Mycobacterial yields (smear and culture) for the 2 sample types (IS and GL) were compared. Four hundred three children (56.6% girls), median age 111 months (interquartile range: 68, 144) were enrolled. Overall yield for acid-fast bacilli and/or Mycobacterium tuberculosis (MTB) by either IS and/or GL was 152 (37.7%). Acid-fast bacilli positivity from IS and GL were 5.7% (23) and 10.4% (42), respectively. Confirmed MTB on culture from IS and GL were 17.9% (72) and 32.5% (127), respectively (P < 0.001). IS and GL identified 17 (4.2%) and 73 (18.1%) additional cases respectively when the other method failed to identify MTB. The combined yields (acid-fast bacilli positivity/MTB) with GL and IS on day 1 (115, 28.5%) were less than that obtained from 2 consecutive GL (135, 33.5%), but better than 2 consecutive IS samples (79, 19.6%; P < 0.001). It is feasible to collect induced sputum and gastric lavage on an ambulatory basis. The yield of MTB obtained by GL is superior to that obtained by IS.