Interferon Gamma Release Assay for the Identification of Latent Tuberculosis Infection in Rural and Remote Settings

There are 2 accepted tests for the identification of latent tuberculosis infection (LTBI): the tuberculin skin test (TST) and the interferon gamma release assay (IGRA). There are some logistical challenges to the IGRA test (e.g., infrastructure, transporting the blood), but the test can be more accurate than the TST in certain populations (e.g., those who have received the bacillus Calmette-Guérin [BCG] vaccine). Despite the desire to use the IGRA test in many jurisdictions in Canada, the test may not always be available, particularly in rural or remote areas. In August 2020, CADTH searched the literature for evidence on the clinical utility, the cost-effectiveness, and guidelines regarding the use of IGRA for the identification of LTBI in rural and remote settings. This report identified 1 systematic review regarding the clinical utility of IGRA in rural and remote settings, but no relevant economic evaluations or guidelines were identified. The purpose of the current report is to summarize and critically appraise this systematic review. This report is a component of a larger CADTH condition-level review on tuberculosis. A condition-level review is an assessment that incorporates all aspects of a condition, from prevention, detection, treatment, and management. For more information on CADTH’s condition-level review of tuberculosis, please visit the project page (https://www.cadth.ca/tuberculosis).