Clinico-microbiological study of extrapulmonary tuberculosis from a teaching institute in North India.

Background: Globally, tuberculosis (TB) poses a severe threat to human health. Prior to the COVID-19 pandemic, TB was the commonest infectious cause of mortality, surpassing HIV/AIDS. A strong index of suspicion is required for the diagnosis of extrapulmonary tuberculosis (EPTB) because of the paucibacillary nature of biological specimens. Primary care physicians, as the first point of contact for patients, are in an ideal position to detect TB early due to its multisystemic nature and varied presentation. This study aims to determine microbiological, demographic, clinical, and changing trends of EPTB in our region. Aim: To study the clinico-microbiological and drug susceptibility profile of patients with confirmed EPTB. Methodology: This was a prospective observational study in which all presumptive EPTB cases were screened, and confirmed EPTB cases were studied using various demographic criteria and clinical aspects. Results: A total of 1425 extrapulmonary samples were obtained from suspected TB cases between 2023-24. Of these, 194 samples with various diagnostic modalities and 68 patients were selected for the study based on inclusion and exclusion criteria. The prevalence of EPTB cases was found to be more prevalent in males, with majority of cases belonging to the 21-30 years age group. The maximum positivity was reported in pleural samples, followed by lymph node aspirates. Cartridge-based nucleic acid amplification test (CBNAAT) was found to be having highest sensitivity followed by solid culture. Rifampicin resistance was 4.4% cases. Conclusions: Since most of the tests rely on the presence of mycobacteria in the specimen, none of them have a 100% sensitivity; thus, suboptimal performance of all assays in the diagnosis of EPTB cases underlines the continuing relevance of systematic clinical investigations for making the diagnosis of EPTB and also calls for the need for novel tests.