tailieunhanh - The Diagnosis of Tuberculosis

Tuberculosis is transmitted from person to person by respiratory droplets. Although some people develop active tuberculosis disease after infection, almost all tuberculosis infections are asymptomatic and remain latent. Latent tuberculosis infection (LTBI) itself progresses to active disease in approximately 5% to 10% of infected persons. The rate of progression is much greater in immunocompromised individuals. The estimated 2 billion people living with LTBI represent a vast reservoir of potential cases of tuberculosis around the world. This reservoir of LTBI is therefore a major barrier to the ultimate control and elimination of tuberculosis. Strategies to combat tuberculosis in regions that are resource-rich aim, first, to identify and treat persons who have active disease; second, to find. | ELSEVIER SAUNDERS Clin Chest Med 26 2005 247 - 271 CLINICS INCHEST MEDICINE The Diagnosis of Tuberculosis Daniel Brodie MD Neil W. Schluger MD Division of Pulmonary Allergy and Critical Care Medicine Columbia University Medical Center 622 West 168th Street PH 8 East Room 101 New York NY 10032 USA Tuberculosis is transmitted from person to person by respiratory droplets. Although some people develop active tuberculosis disease after infection almost all tuberculosis infections are asymptomatic and remain latent. Latent tuberculosis infection LTBI itself progresses to active disease in approximately 5 to 10 of infected persons. The rate of progression is much greater in immunocompromised individuals. The estimated 2 billion people living with LTBI represent a vast reservoir of potential cases of tuberculosis around the world. This reservoir of LTBI is therefore a major barrier to the ultimate control and elimination of tuberculosis. Strategies to combat tuberculosis in regions that are resource-rich aim first to identify and treat persons who have active disease second to find and treat contacts of cases of active disease who develop LTBI and third to screen high-risk populations and treat LTBI 1 . Diagnosis and treatment of LTBI are crucial in this effort. In most of the world however resources are devoted exclusively to the highest priorities of tuberculosis control identification and treatment of active disease 1 for lack of resources LTBI is neither diagnosed nor treated. Diagnostic testing for both LTBI and active disease has changed little during the last century. Because of limitations in available tests there has long been a clear need for better diagnostic tests. LTBI until very recently has been diagnosed exclusively by the tuberculin skin test TST . The TST is fraught with problems including relatively poor sensitivity Corresponding author. E-mail address ns311@ . Schluger . and specificity. Newer tests for LTBI offer the promise of greatly