Tuberculosis (TB) Testing: Types, Accuracy & What to Expect

According to the Mayo Clinic, tuberculosis kills nearly 2 million worldwide per year. Tuberculosis is an airborne disease that can be highly contagious. Many people don't even know that they've been infected until they get tested.

The Facts

• There are different types of tests for tuberculosis. If your doctor suspects that you may have been infected with tuberculosis, he will usually perform a complete medical evaluation, including tests for TB.

Skin Test

• The skin test is the most common test for tuberculosis. There are two types of skin tests, but the Mantoux test is used more often since it's generally the most accurate. The Mantoux skin test is performed by injecting a small amount of PPD tuberculin underneath the skin on the inside of your forearm. If a small red bump appears within 72 hours, a TB infection is likely.

Blood Test

• Blood tests are more accurate than traditional skin tests, and produce a much quicker result. Blood tests are mostly used if you are at high risk for TB but tested negative on the skin test.

Other Tests

• If you have tested positive for tuberculosis, other tests may be performed to confirm the diagnosis. These tests include chest X-rays, CT scans and culture tests.

Treatment

• Tuberculosis is often treated with antibiotics. The antibiotics usually have to be taken for 6 to 9 months to fully get rid of the tuberculosis bacteria.