New Advances in Diagnosis of Latent Tuberculosis Infection: A Review Article

Abstract

Context: It has been estimated that one-third of the world's population are suffering from latent tuberculosis infection (LTBI). In order to control tuberculosis in high-risk groups proper diagnosis and treatment is essential. Evidence Acquisition: Useless and expensive tests such as unfocused population-based tests can lead to futile and unnecessary treatments. Targeted screening approaches and individualization of LTBI treatment protocols must be a priority. Results: Diagnostic methods with immune based tests such as the tuberculin skin test (TST) or interferon gamma release assays (IGRA) can accurately detect LTBI. However, interferon-gamma release assays have higher specificity than TST in Bacille Camette-Gurin (BCG)-vaccinated populations; both tests are precise to identify latent tuberculosis. However, it is of great concern that both tests have insignificant roles in predicting risk of progression to active tuberculosis. Conclusions: Here we review the clinical applications, advantages, and limitations of the tuberculin skin test and interferon-gamma release assays and provide an overview of the most recent systematic reviews conducted for the comparison of these tests.

Molecular Detection of Isoniazid and Rifampin Resistance in Mycobacterium tuberculosis Isolates from Lorestan Province, Iran from 2014 to 2017

“…Point mutations, deletions, or insertions have been described for all of the first-line drugs (isoniazid, rifampin, pyrazinamide, ethambutol, and streptomycin), and for the several second-line and newer drugs (5). Thus, the establishment of molecular assays allows the rapid detection of drug resistance in clinical MTB isolates (6).…”