Evaluation of truenat pcr and mgit liquid culture for diagnosing cervical tuberculous lymphadenitis in a tertiary care center in dehradun

Background: Tuberculosis (TB) remains a major public health concern, with extrapulmonary TB (EPTB) posing significant diagnostic challenges. Cervical tuberculous lymphadenitis is the most common form of EPTB,35% of EPTB and 15-20% of all cases of Tuberculosis (TB).The diagnosis is complicated by the paucibacillary nature of specimen and the limitations of conventional diagnostic methods. This study aimed to evaluate the diagnostic efficacy of Truenat polymerase chain reaction (PCR) compared to Mycobacteria Growth Indicator Tube (MGIT) liquid culture in detecting Mycobacterium tuberculosis (MTB) in cervical lymph node aspirate samples. Methods: A total of 100 clinically suspected cases of cervical tuberculous lymphadenitis were evaluated in this comparative study, from April 2023 to March 2024. Fine-needle aspiration cytology (FNAC) samples were collected and processed for both Truenat PCR and MGIT liquid culture. Ziehl-Neelsen (ZN) staining was also performed. Culture results were taken as the gold standard for statistical analysis, and diagnostic parameters such as sensitivity and specificity were calculated. Results: Out of 100 samples, MTB was detected in 29% (29/100) using Truenat PCR and 22% (22/100) using MGIT liquid culture. Among the 29 PCR-positive samples, 20 (69%) were also culture-positive, while 9 (31%) were culture-negative. Of the 22 MGIT-positive cases, 20 (91%) were also detected by PCR, whereas 2 (9%) were PCR-negative. ZN staining was positive in only 10% of samples. The sensitivity and specificity of Truenat PCR compared to MGIT culture were found to be 90.9% and 88.46%, respectively. Conclusion: Truenat PCR demonstrated higher sensitivity than MGIT culture, making it a valuable diagnostic tool for cervical tuberculous lymphadenitis. Given its rapid turnaround time and high accuracy, integrating Truenat into routine diagnostic workflows could improve early case detection, especially in resource-limited settings. This aligns with India's TB elimination goals and the global End TB strategy.