Chest Radiography and Xpert MTB/RIF® Testing in Persons with Presumptive Pulmonary TB: Gaps and Challenges from a District in Karnataka, India

Abstract

Background. In India, as per the latest diagnostic algorithm, all persons with presumptive pulmonary TB (PPTB) are required to undergo sputum smear examination and chest radiography (CXR) upfront. Those with sputum smear positive, sputum smear negative, but CXR lesions suggestive of TB or those with strong clinical suspicion of TB are expected to undergo Xpert MTB/RIF® assay test (also known as CB-NAAT (cartridge-based nucleic acid amplification test)). Objective. To assess what proportion of PPTB who are undergoing sputum smear examination at microscopy centers of public health facilities have undergone CXR and CB-NAAT. To explore the barriers for uptake of CXR and CB-NAAT from the public health care provider’s perspective. Methods. We conducted a sequential explanatory mixed-methods study in Chikkaballapur district of Karnataka State, South India. The quantitative component involved a review of records of PPTB who had undergone sputum smear examination in a representative sample of seven microscopy centers. The qualitative component involved key informant interviews with four medical officers and group interviews with 9 paramedical staff. Results. In February and March 2019, about 732 PPTB had undergone smear examination. Of these, 301 (41%) had undergone CXR and 49 (7%) had undergone CB-NAAT. The proportion of PPTB who had undergone CXR varied across the seven microscopy centers (0% to 89%). CB-NAAT was higher in PPTB from urban areas when compared to rural areas (8% vs. 3%) and in those who were smear positive when compared to smear negative (65% vs. 2%). The major barriers for CXR and CB-NAAT were nonavailability of these tests at all microscopy centers and patients’ reluctance to travel to the facilities where CXR and CB-NAAT services are available. Conclusions. CXR and CB-NAAT of PPTB are suboptimal. RNTCP should undertake measures to address these gaps in implementing its latest diagnostic algorithm.