Positive Tests for Tuberculosis

What does it mean to have a positive test (skin or blood) for tuberculosis?

When TB germs first enter the body there may be no sign of an infection or illness and the only way to detect the infection is to test for it with either a skin or blood test. Since the skin test can detect other bacteria a blood test specific for tuberculosis (mycobacterium tuberculosis) is the more specific test. The blood test should be ordered for anyone who has had BCG vaccine, was born, lived in or travels to countries with high rates of tuberculosis disease. Anyone with a previous positive skin or blood test should not have the test repeated.

An early tuberculosis infection often does not have any symptoms; it’s important to know that TB germs may spread through the blood stream to the lungs and other organs, including the spine and brain. The tuberculosis infection may live in your body for years, even decades before they become active, making you sick. This is why your healthcare provider may want you tested before starting you on certain medications that may affect your immune system.

Dormant ("Sleeping") Tuberculosis

The tuberculosis germ may remain dormant or “sleeping” for years or decades until something changes that causes them to "awaken" and cause tuberculosis; just as "dead" roots and bare trees awaken in the spring after being dormant for several months. Dormant TB germs can also be detected in healthy persons with tuberculosis testing. In the United States we know that about 13 million Americans are infected with TB germs, although most of the infections are in the dormant stage.

Any person who has been exposed to an active case of tuberculosis may have been infected. Any change in your immune system, for example if you develop diabetes or take certain medications, may cause the tuberculosis germ to become active. The tuberculosis infection can be treated with a short course of oral medication prescribed by your healthcare provider or through the Tuberculosis Clinic at your local Health Department.

Prevention of Tuberculosis Disease

One of the greatest advances in tuberculosis today, after identifying the infection, is that by simply taking a short course of prescribed medication, the development of tuberculosis disease can be prevented.

Questions, Need for Information

For more information regarding tuberculosis please see the attached http://www.cdc.gov/tb/default.htm or contact Chester County Health Department at (610) 344-6225, option #2, then option #4 for more information.


Tuberculosis statistics and information