Diagnosis and treatment of pulmonary tuberculosis in one day : Way forward for END TB Strategy 2015

Abstract

Background: According to Revised National Tuberculosis Control Program (RNTCP), diagnosis of pulmonary tuberculosis (TB) in India requires examination of two sputum samples collected over 2 days, that is, “spot” and next day “morning” samples. Objective: To assess the feasibility of diagnosing pulmonary TB by examining two spot sputum samples in 1 day and to compare this approach with the current RNTCP protocol. Materials and Method: A total of 375 subjects having cough >2 weeks were enrolled into the study. Three sputum samples were collected from each of the study participant; first spot (S1), second extra-spot (S2) sample 1 h after collection of the first sample, and third morning (M) sample collected next day morning. These specimens were subjected to standard sputum smear microscopy for acid-fast bacilli as per RNTCP guidelines. For 1-day protocol, results of “S1 and S2” samples and for 2-day protocol results of “S1 and M” samples were considered. Results: The number of sputum-positive pulmonary TB cases diagnosed with standard 2-day protocol was 119, whereas the experimental 1-day protocol diagnosed 120 cases (P = 0.7). Comparing with standard 2-day protocol, this new 1-day protocol had sensitivity 98.32%, specificity 100%, positive predictive value 100%, and negative predictive value 99.17%. Conclusion: Single-day method can be adopted as the standard diagnostic approach for pulmonary TB after large-scale multicenter randomized controlled trials.

Keywords

• Acid-fast bacillus
• Mycobacterium tuberculosis
• pulmonary tuberculosis
• sputum microscopy
• Ziehl–Neelsen stain