One-sample two-smear versus two-sample two-smear approach for the diagnosis of pulmonary tuberculosis

BACKGROUND: To evaluate the efficacy of one-sputum sample two-smear approach for the diagnosis of pulmonary tuberculosis (PT). MATERIALS AND METHODS: Data from January 2012 to December 2015 were analyzed to find (1) number of smear positives (SPs) by spot (S) sample with one and two smears; (2) number of SPs by morning (M) sample with one and two smears; and (iii) number of SPs by two samples with two smears, that is, same-day (SS(2)) and spot morning (SM) approaches. The Chi-square test was used to evaluate the statistical difference in SP cases. RESULTS: With one-sample two-smear approach, the smear positivity (SPT) was 87% and 87.5%, for S and M samples, respectively, for Ziehl–Neelsen (ZN) staining; whereas, SPT was 96% and 97%, respectively, for S and M samples, for fluorescent staining (FS) technique. With two-sample two-smear approach, for ZN staining, SPT was 89% each and for FS technique, SPT was 97% and 99%, respectively, for SS(2) and SM approaches. The difference was not statistically significant (P > 0.05) between one- and two-sample approaches in the staining techniques. CONCLUSION: Significant number of SP cases are identified by S sample two-smear approach. Thus, the World Health Organization/Revised National Tuberculosis Control Programme can initiate S sample two-smear approach for the diagnosis of PT.