New tools for detection of latent tuberculosis.

Abstract

Tuberculosis is a serious public health problem worldwide, particularly in developing countries. In Colombia, the focus is on the clinical management of patients with active disease, but not on preventive programs that identify and treat individuals with a latent tuberculosis infection. This review emphasized the importance of preventative programs and their critical role in the curtailment of infection dissemination in the community. An effective program includes chemoprophylactic treatment of household contacts and detection of individuals with latent tuberculosis infection and with high risk of reactivation of disease. The tuberculin skin test has been used effectively for more than 100 years, despite inherent sensitivity and specificity limitations. Herein the advances provided by a new generation of immunoassays are reviewed, includingthe commercially-available Quantiferon and the experimental development of ELISPOT. Both are based on the detection of IFNgamma secretion by peripheral T cells upon incubation with Mycobacterium tuberculosis antigens. Finally, the importance of molecular techniques aimed at detecting DNA from the mycobacterium is discussed as a possible complement to the described immunoassays.