Comparing Same Day Sputum Microscopy with Conventional Sputum Microscopy for the Diagnosis of Tuberculosis – Chhattisgarh, India

Background: The World Health Organization (WHO) recommends same day sputum microscopy (spot-spot) in preference to conventional strategy (spot-morning) for the diagnosis of smear positive tuberculosis with the view that completing diagnosis on a single day may be more convenient to the patients and reduce pre-treatment losses to follow-up. Methods: We conducted a cross-sectional study in seven selected district level hospitals of Chhattisgarh State, India. During October 2012 – March 2013, two sputum specimens (spot-early morning) were collected from consecutively enrolled adult (≥18 years) presumptive TB patients as per current national guidelines. In addition, a second sample was collected (one hour after the collection of first spot sample) from the same patients. All the samples were examined by ziehl-Neelsen (ZN) microscopy. McNemar’s test was used to compare statistical differences in the proportion smear positive between the two approaches (spot-spot versus spot-morning). Results: Of 2551 presumptive TB patients, 69 % were male. All patients provided the first spot specimen, 2361 (93%) provided the second spot specimen, and 2435 (96%) provided an early morning specimen. 72 % of specimens were mucopurulent in conventional strategy as compared to 60 % in same day strategy. The proportion of smear-positive patients diagnosed by same day microscopy was 14%, as compared to 17 % by the conventional method (p<0.001)