The Mantoux test is a skin test used to identify individuals who have previously been infected with Mycobacterium tuberculosis, the bacterium responsible for tuberculosis infection and disease in humans. The test is performed by injecting 0.1 ml of a solution that contains an extract of cultures of the bacterium, called tuberculin, into the dermis layer of the skin of the forearm with a 27-gauge needle. In individuals who previously have been infected with the bacterium, either clinically or subclinically, the test may stimulate a reaction (called "delayed hypersensitivity reaction") if the body's immune system recognizes the antigenic components in the test solution. The skin reaction is "read" forty-eight to seventy-two hours after the injection by measuring the amount of induration (swelling) at the injection site in millimeters. The sensitivity and the specificity of the test depend upon many variables, and false negative results are common.
JOHN L. STAUFFER
(SEE ALSO: Tuberculosis)
American Thoracic Society (2000). "Diagnostic Standards and Classification of Tuberculosis in Adults and Children." American Journal of Respiratory Critical Care Medicine 161:1376–1395.