 Objectives: The primary objectives of the IMPI Trial are: a to determine the effectiveness of oral prednisolone and Mycobacterium w immunotherapy in reducing the composite outcome of death, constriction or pericardial drainage for cardiac tamponade in patients with tuberculous pericardial effusion, b to assess the safety and interactive effects of the co-administration of prednisolone and Mycobacterium w immunotherapy, and c to demonstrate the feasibility of conducting a study in patients with tuberculous pericardial effusion in sub-Saharan Africa, and establish the infrastructure for conducting the full-scale IMPI trial in an internal pilot phase of the first 200 participants. 