Abstract
Accurate diagnosis of tuberculosis (TB) infection is an important component of tuberculosis
control programs in many countries. Identification of persons with asymptomatic, or
latent, tuberculosis infection allows for treatment of individuals at high risk for
progressing to active disease so that the overall burden of tuberculosis disease is
diminished. In the United States, targeted testing and treatment of latent tuberculosis
infection (LTI) are major components of the Centers for Disease Control and Prevention's
efforts at TB elimination. This review focuses on the comparative utility of tuberculin
skin testing and interferon-gamma release assays (IGRAs) to diagnose LTI. Commercially
available IGRAs have superior sensitivity and specificity compared with conventional
tuberculin skin testingin some settings (particularly bacille-Calmette Guérin–vaccinated
individuals). Also discussed are the performance characteristics of these tests in
specific populations, including foreign-born persons from high-prevalence countries,
close contacts of actively infected patients, immunocompromised populations, and health
care workers.
Keywords
tuberculosis - latent tuberculosis - tuberculin skin test - PPD - interferon gamma
release assays - prophylaxis
