Spectrum of Pulmonary and ExtraPulmonary Tuberculosis: A Retrospective Study from Northeast India

Introduction: Tuberculosis (TB) remains a global health problem with India having the highest burden. The commonest site of TB is the lungs (85%), the remaining 15% being clubbed as extra-pulmonary TB (EPTB). The diagnosis of TB poses a number of challenges which becomes more pronounced in resource limited settings. Aim: To ascertain the demographic characteristics, clinical spectrum and methods of diagnosis of TB in a tertiary care centre having limited culture based facilities. Materials and Methods: Hospital-based retrospective study in TB patients registered for treatment in a DOTS centre attached to a tertiary care teaching hospital in Northeast India, from January 2013 to December 2014. Data was collected from the TB registers and patient record sheets of the DOTS centre. All TB patients registered under DOTS centre were included in the study while patients found to have alternative diagnosis leading to discontinuation of anti-tubercular therapy were excluded. Results: There were 1344 participants with a male to female ratio of 1.15:1. Most of the patients (30.95%) were in the age group 21-30 years followed by 31-40 years (18.82%), with a mean and median age of 32.78±15.64 and 30 years respectively. Majority of patients had EPTB (57.22%). Majority of the patients with TB (83.22% of EPTB and 77.21% of PTB) were in the newly detected category. Among EPTB cases, pleural effusion was commonest (30.04%), followed by lymphadenitis (24.58%), abdominal TB (13.91%) and central nervous system TB (12.35%). Sputum for AFB was the commonest mode of diagnosis (29.91%) followed by body fluid analysis (25.30%), Fine Needle Aspiration (FNA) cytology (17.78%) radio-imaging techniques (15.57%) and DNA PCR (1.12%). Overall, acid fast bacilli could be demonstrated in 38.76% of the cases. Sputum was the commonest sample positive for AFB (77.16%), followed FNA specimens from lymph nodes (19.39%). Molecular methods (DNA PCR) were used for the diagnosis in only 1.12% of cases. Conclusion: Our study showed a high burden of TB with a very high proportion with EPTB. AFB demonstration, supplemented by ancillary investigations formed the cornerstone of TB diagnosis. Considering the very high EPTB prevalence, there is need for advanced diagnostic facilities for better diagnostic yield.