Diagnosis and treatment of latent tuberculosis infection

ABSTRACT

Tuberculosis (TB) is still an important cause of morbidity and mortality worldwide. Nearly one-third of the world's population is latently infected with Mycobacterium tuberculosis, and 10% of them will develop active TB during their lifetime. The tuberculin skin test or interferon-gamma release assay (IGRA) is the method for diagnosis of latent TB infection. Although commercially available IGRAs have limitations in serial testing, and testing children and immunosuppressive patients, IGRAs have superior sensitivity and specificity compared with conventional tuberculin skin testing, especially in Bacillus Calmette-Guerin vaccinated populations. For the treatment of latent TB infection, 9 months isoniazid is the standard treatment in Republic of Korea. However, shorter treatment regimens, including 4 months of rifampin, 3 months of isoniazid/rifampin, and once weekly isoniazid/rifapentine are currently alternatives. Identification and treatment of latent TB infection has lowered the TB incidence in developed countries. Therefore, for TB control, diagnosis and treatment of latent TB infection is important. However, there is lack of research on latent TB infection in South Korea. To revise the guideline, a large prospective trial on the treatment of latent TB infection is needed.