Community-level screening and intervention participant recruitment
TB, MTB infection
INFECTIOUS DISEASES, PULMONARY TUBERCULOSIS
Between 18 September 2017 and 29 August 2018, a community-level baseline screening was initially conducted to identify participants with radiographically inactive TB using chest DR examination. To improve the accuracy of the radiographic diagnosis of inactive TB, two-round chest DR screening combined with MTB infection testing was conducted. In the first round, participants who were initially identified with radiographically inactive TB lesions by one radiologist would be introduced for QFT testing. Those with QFT-positive results were then invited for the second-round screening survey, in an interval of three to six months (between 30 August 2018 and 15 October 2018) to identify eligible participants for the RCT. Specifically, chest DR was repeated for QFT-positive participants with radiographically inactive TB lesions to exclude unstable lesions with progression. In this round of screening, a panel of radiologists, consisting of one local radiologist and one radiologist from provincial infectious diseases hospital, read each image together and provided a common report after discussion. If the participants were confirmed to have radiological findings suggestive of suspected TB, microbiological testing including sputum smear, culture and GeneXpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) would be done to exclude currently active TB. TB diagnosis was made according to the National Health Industry Standard on Diagnosis for Pulmonary Tuberculosis (WS288-2017) [