A randomised, placebo-control phase III study to assess the safety and efficacy of the MPT64 patch test in the diagnosis of active tuberculosis (TB)

INTERVENTION: 1. Diagnostic phase: application of a transdermal patch to each forearm, one containing placebo and the other MPT64 (study staff and patients blinded to allocation) with removal and reading of result at days 4 and 6. All patients receive full work‐up for active pulmonary TB including clinical evaluation, two sputum cultures (each by two methods), chest radiograph and (on day 4) purified protein derivative (PPD) skin testing. 2. Follow‐up phase: all participants are followed up at 3 months to verify correct baseline assignment as TB or non‐TB; at months 9, 12, 15 and 18 all participants are investigated fully once more for TB (as above) and repeat patch testing is performed. In a subgroup of 30 consenting participants with positive reactions, skin punch biopsies are performed. CONDITION: Active pulmonary tuberculosis. ; Infections and Infestations ; Tuberculosis PRIMARY OUTCOME: The objective is to assess the sensitivity and specificity of the MPT64 patch test in the diagnosis of pulmonary TB ‐ the outcome of interest is therefore the concordance of patch test results with the results of the conventional gold‐standard investigations performed concurrently. SECONDARY OUTCOME: 1. To assess the above performance characteristics in patient subgroups including those with smear‐positive disease and smear‐negative disease; 2. To determine the effect (if any) of age, HIV status, PPD response upon patch test performance; 3. To determine the response over time of both initial reactors and non‐reactors and TB and non‐TB patients; 4. To characterize the histological response in patch test reactors INCLUSION CRITERIA: TB suspects undergoing investigation at selected health centres for pulmonary TB within the National TB Control Programme of Peru.