Optimal Treatment Duration for Radiographically Apparent, Bacteriologically Unconfirmed TB, Identified Through Active Case Finding (RADIO-TB Trial)

People living in high TB burden communities who undergo active case finding for TB may have chest X-ray changes suggestive of TB but their sputum test can be negative for the TB bacteria or they are unable to provide a sputum sample. This means they have bacteriologically unconfirmed TB. These individuals often have minimal or no symptoms and face uncertainty in clinical management-either receiving full 24-weeks TB treatment or often being discharged without treatment, risking loss to follow-up.

The RADIO-TB trial aims to address the following main questions in relation to people with bacteriologically unconfirmed TB.

1. What is the risk of progression if treatment is not immediately started but there is close and careful follow-up over 78 weeks? 2. If treatment is started immediately what is the shortest duration of TB treatment that is as effective as the standard 24-week TB treatment? 3. Are there better tests to confirm TB than the current routinely used, sputum-based tests? 4. What is the cost effectiveness of different treatment strategies and what might the impact on transmission be within communities?

Participants in the trial will be randomized into six groups: five receiving immediate standard TB treatment of varying durations (8 to 24 weeks), and one receiving deferred treatment with close monitoring. Deferred treatment will be initiated only if clinical deterioration occurs or TB is later confirmed. Participants will be closely followed for 78 weeks with at least 11 clinic visits.