TB is a preventable disease, even in those who have been exposed to an infected person. Skin testing (PPD) for TB is used in high risk populations or in people who may have been exposed to TB, such as health care workers.
A positive skin test in a person with no symptoms of TB is a sign of a previous exposure to TB. Discuss preventive therapy with your doctor. People who have been exposed to TB should be skin tested immediately and have a follow-up test at a later date (usually 12 weeks), if the first test is negative.
Prompt treatment is extremely important in controlling the spread of TB from those who have active TB disease to those who have never been infected with TB.
Some countries with a high rate of TB give people a BCG vaccination to prevent TB. However, the effectiveness of this vaccine is controversial and it is not routinely used in the United States.
Iseman MD. Tuberculosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 345.
Fitzgerald DW, Sterling TR, Haas DW. Mycobacterium tuberculosis. In: Mandell GL, Bennett JE, Dolan R, eds. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 7th ed. Orlando, FL: Saunders Elsevier; 2009:chap 250.