Testing for tuberculosis infection.

The diagnosis and management of latent tuberculosis infection (LTBI) has evolved over the last several years. New guidelines have been issued as our knowledge base continues to improve. We summarize the current understanding of this important topic and review the pathophysiology of the purified protein derivative test, its use and interpretation, the concept of targeted tuberculin testing, the management of latent tuberculosis infection (LTBI), and the role of the newer testing modalities.