TB is a preventable disease, even in those who have been exposed to an infected person. Skin testing (PPD) is a screening test for TB used in high risk populations or in those who may have been exposed to TB (such as all health care workers).

A positive test indicates prior TB exposure and indications for preventive therapy should be discussed with your doctor. Individuals exposed to tuberculosis should be skin tested immediately and the skin test repeated at a later date, if the initial test is negative.

Prompt treatment is extremely important in controlling the spread of tuberculosis for those who have already progressed to active TB disease.

A BCG vaccination to prevent TB is given in some countries with a high incidence of TB, but its effectiveness remains controversial. It is not routinely used in the United States. People who have had BCG may still be skin tested for TB and results of testing (if positive) discussed with one's doctor.