Utility of Conventional Techniques for Diagnosis of Pulmonary and Extrapulmonary Tuberculosis: Study from a Tertiary Care Hospital in North India

Though pulmonary tuberculosis (PTB) remains the most common presentation, extra pulmonary tuberculosis (EXTB) is another significant clinical problem and due to paucibacillary nature, remains a challenge for diagnosis. The aim of this study is to evaluate the utility of smear microscopy and culture for detection of Mycobacteria in pulmonary and extra pulmonary specimens. This retrospective study was carried out in Microbiology Department at Christian Medical College Ludhiana, from January 2013 to September 2013. A total of 1636 clinical specimens received for routine mycobacterial cultivation were processed. All clinical specimens were cultured on Lowenstein-Jensen (LJ) medium after homogenization and decontamination by modified Petroff’s method. Consequently identified by AFB staining (ZiehlNeelsen method). Of the 1636 cases, 13 of the cases were of extra-pulmonary (EPTB) origin where as 34 were of pulmonary tuberculosis. By microscopy for AFB 9(19%) samples and by culture (LJ) 14(30%) samples were positive. Smear microscopy and culture together yielded a positivity rate of 24 (51%).This can be concluded from our study, smear microscopy and culture still remains the gold standard for diagnosis of pulmonary and extra pulmonary tuberculosis with limited resources and poor infrastructure in developing countries like India.