Tuberculin Skin Test: New Insight

The “captain of all these men of death”, Tuberculosis has been a scourge of the humankind from time immemorial. Different outcomes may result following inhalation of an infectious droplet containing Mycobacterium tuberculosis. The probability of development of active clinical tuberculosis after being infected with Mycobacterium bacillus is very small. The majority of immunocompetent individuals, either eliminate Mycobacterium tuberculosis or contain it in a latent state in which an equilibrium is established between host and pathogen. Thus, identifying and treating persons with latent infections is an important public health measure. The targeted tuberculin skin test is the most accepted method for Latent Tuberculosis infection screening. This book reviews the history of this technique with new insights, which is closely linked to the symbolism and mythology of an illness that at one time was known as the white plague aiming to calculate the prevalence of tuberculin positivity in different categories of persons by using different doses so that the cases with low reactivity should not be missed.