A prospective observational multicentric clinical trial to evaluate microscopic examination of acid-fast bacilli in sputum by artificial intelligence-based microscopy system

Abstract

Microscopy-based tuberculosis (TB) diagnosis i.e., Ziehl-Neelsen (ZN) stained smear screening still remains the primary diagnostic method in resource poor and high TB burden countries, however itrequires considerable experience and is bound to human errors. In remote areas, wherever expert microscopist is not available, timely diagnosis at initial level is not possible. Artificial intelligence (AI)-based microscopy may be a solution to this problem. A prospective observational multi-centric clinical trial to evaluate microscopic examination of acid-fast bacilli (AFB) in sputum by the AI based system was done in three hospitals in Northern India. Sputum samples from 400 clinically suspected cases of pulmonary tuberculosis were collected from three centres. Ziehl-Neelsen staining of smears was done. All the smears were observed by 3 microscopist and the AI based microscopy system. AI based microscopy was found to have a sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 89.25%, 92.15%, 75.45%, 96.94%, 91.53% respectively. AI based sputum microscopy has an acceptable degree of accuracy, PPV, NPV, specificity and sensitivity and thus may be used as a screening tool for the diagnosis of pulmonary tuberculosis.