Adel AL-Harbie, Kim Picozzi, Michael Thrusfield, Ali Sadek and Susan C Welburn
The Bacelle Calmette-Guérin (BCG) vaccine has existed for 90 years and is the most widely used of all current national childhood immunization programmes. The impact of BCG vaccination on transmission of Mycobacterium tuberculosis is not clear or whether BCG confers lifelong immunity through sufficient protection against formation and diagnosis of latent tuberculosis infection (LTBI) is recently questionable especially in tuberculosis endemic regions and vaccinated high risk individuals, which was discussed along the paper work following a new evidence- based criteria for LTBI diagnosis.