The tuberculin test is one of the methods of tuberculosis diagnosis in children and adolescents. It is also a test to check the status of allergy to Mycobacterium tuberculosis antigens prior to tuberculosis vaccination (BCG). How is the tuberculin test performed? How is the tuberculin test result interpreted? What are the side effects of the tuberculin test?
Tuberculin test(Mantoux-Mtx test) is used to evaluate the effectiveness of a previous TB vaccination. How is the tuberculin test going?
Inject 0.1 ml of tuberculin (that is, the prepared mycobacterial filtratetuberculosis ) into the center of the anterior region of the left forearm. After the injection, a whitish, porous, 7-9 mm diameter bubble appears on your hand, which disappears after a few minutes. If you have been injected with the wrong amount of tuberculin, it has been injected too deeply, or there has been blood at the injection site, repeat the attempt on the same day. in a different place on the skin. The result oftuberculin testis read after 3 days (72 hours). Using a special ruler with an exact millimeter scale, the doctor or nurse reads the diameter of the infiltrate (the swelling and redness on the skin are not taken into account).
Tuberculin test: interpretation of the result
If you arepositive , you are or have been infected with Mycobacterium tuberculosis. It could also mean you have had a BCG vaccination. The size of the reaction is also influenced by the age at which the test is performed and the time since infection or vaccination. An infiltrate with a diameter smaller than 6 mm meansnegative result , and greater than 12 mm - the so-calledover-positive . An infiltrate with a diameter greater than or equal to 5 mm is considered a positive result in persons who: are infected with HIV, have had recent close contact with a tuberculosis patient, have had tuberculosis early, but have healed, and are considered positive for positive in people who have recently stayed in countries with a high incidence of tuberculosis and have reduced immunity.