Encounter

PPD Skin Test
 
Tuberculosis is a serious infection caused by the bacterium Mycobacterium tuberculosis. this bacterium infects the lungs.Tuberculosis is transmitted through TB contaminated air. Vaccination, one of the preventions of tuberculosis is very important.

The tuberculin or PPD test determines whether an individual's immune system is strong against the bacterium that causes tuberculosis. Skin tests are read 48-72 hours after the injection of the vaccine. The presence or absence of a swelling bases the reading of the test. I found out that when an individual PPD skin test gives a positive result, it does not mean that the individual has tuberculosis. A blood test as long as an X-Ray would be needed to check for the presence of M. tuberculosis.

A positive PPD test could mean that the individual has been exposed to M. tuberculosis. the bacterium is laying dormant in the individual's body. Statistics shows that about 10% of individuals with dormant TB would develop the infection.

http://www.niaid.nih.gov/topics/tuberculosis/understanding/pages/cause.aspx