In the United States, latent tuberculosis infection (LTBI) affects between 10 and 15 million people, of whom 10% may develop active tuberculosis disease. People at increased risk for tuberculosis reactivation include recent immigrants from countries with a high incidence of tuberculosis, children younger than age 5, people who have been infected with Mycobacterium tuberculosis within the past 2 years, or people with immunosuppression for a variety of reasons. Appropriate diagnosis and treatment of LTBI are critical for controlling and eventually eliminating tuberculosis as a public health problem. Although the tuberculin skin test is the traditional diagnostic measure for LTBI, reduced specificity has promoted the development and utilization of the interferon release assays as an in vitro blood test with specific antigens to M. tuberculosis (QuantiFERON-TB Gold In-Tube test and the T.SPOT-TB test are commercially available). Despite the rise of the new diagnostic tests, however, there is still no gold standard for diagnosing LTBI, and epidemiologic risks and comorbidities need to be taken into account before initiating therapy. Current diagnostic tests combined with recommended treatment regimens are valuable tools that, when used correctly, promise to hurry the elimination of tuberculosis. (J Am Board Fam Med 2014;27:704 -712.).

Infectious diseases Respiratory Tract Diseases

HIV Infections Immunocompromised Host human risk assessment comorbidity trends immunocompromised patient statistics and numerical data interferon gamma release assay Interferon-gamma Release Tests Mycobacterium tuberculosis procedures analogs and derivatives health United States disease course Humans Treatment Outcome Antitubercular Agents Rifampin tuberculostatic agent latent tuberculosis in vitro study rifapentine gamma interferon Review antigen specificity tuberculin test isoniazid global health Disease Progression rifampicin gold standard