BCG: Bacille Calmette-Guerin vaccine; a tuberculosis vaccine developed for use in tuberculosis-endemic countries.
Cytokine: Small proteins important in cell communication, such as signaling immune responses.
IFN-g: Also known as the interferon-gamma released from an individual's T-cell lymphocytes (white blood cells) when mixed with proteins derived from M. tuberculosis antigens. IFN-g is a cytokine.
IGRA: Interferon gamma release assays are whole blood tests developed for measuring the immune response to Mycobacterium tuberculosis.
Incidence: The rate of persons who develop a condition or disease during a particular time period.
Induration: Tuberculin skin test reaction is measured in millimeters - the zone at the location where the subcutaneous injection is given on the forearm. This zone is typically a raised hard bump, red in color, and inflamed.
LTBI: Latent tuberculosis infection; LTBI is a condition where an individual harbors Mycobacterium tuberculosis bacteria but may not demonstrate symptoms. The bacteria are inactive or dormant, but may become energized in the future.
Mantoux technique: Method used to perform the tuberculin skin test.
MTB: Mycobacterium tuberculosis bacteria.
Mycobacterium tuberculosis complex: A complex of organisms (eg., M. tuberculosis, M. bovis, M. africanum, M. microti, M. canetti, M. pinnipedii, M. mungi, M. caprae). Mycobacterium tuberculosis is the most common of this complex to cause TB disease in humans, while the other members of the complex cause disease similar to TB.
Peptide: Amino acids linked by chemical bonds. Proteins functioning as tuberculosis-specific antigens for use in IGRA blood tests are made from polypeptides.
PPD: Purified protein derivative (PPD) is the solution injected into the forearm during a tuberculin skin test. PPD is made from batched human strains of M. tuberculosis grown on a protein-free synthetic medium and inactivated.
Prevalence: The proportion of persons who have a condition or are being treated for a disease during a particular time period.
TB (active): Tuberculosis; Active TB disease caused by Mycobacterium tuberculosis bacteria. Active TB disease is a condition in which people infected with Mycobacterium tuberculosis harbor the bacteria and display one or more symptoms.
TST: Tuberculin skin test. A skin test used to screen an individual's antibody response to Mycobacterium tuberculosis antigens present in purified protein derivative (PPD) tuberculin solution.
