Use of tuberculosis interferon-gamma release assays (IGRAs) in low- and middle-income countries
The majority of IGRA studies have been performed in high-income countries and mere extrapolation to low- and middle-income settings with high background TB infection rates is not appropriate. Systematic reviews have suggested that IGRA performance differs in high- versus low TB and HIV incidence settings, with relatively lower sensitivity in high-burden settings. The WHO Stop TB Department (WHO-STB) therefore commissioned systematic reviews on the use of IGRAs in low- and middle-income countries, in pre-defined target groups, with funding support from the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) and TREAT-TB/The Union. The target groups and major findings of the GRADE evidence synthesis process are summarised below.
This Policy Statement applies to the use of commercial IGRAs in low- and middle-income countries only. Several international guidelines on IGRA use in high-income countries are available. This Policy Statement is not intended to apply to high-income countries or to supersede their national guidelines.