Frequently Asked Questions & Answers


What is tuberculosis (TB)?

Tuberculosis, or TB, is an infectious disease caused by the bacterium Mycobacterium tuberculosis. Tuberculosis was once the leading cause of death in the United States, but it can now be successfully treated if discovered in time.

Microscopic droplets suspended in the air pass the TB organism from person to person. Infection can occur when an uninfected person comes in contact with someone who has active tuberculosis.

People who are exposed to TB may never get sick. They develop what is called latent TB infection. A person with latent TB is not contagious and does not show any signs or symptoms of being sick. The immune system controls the infection. Latent TB may develop into active TB if the immune system becomes weakened. A person with active TB disease is sick and shows signs and symptoms of the disease (e.g., persistent cough, weight loss). People with active TB are infectious and can spread the TB bacterium to others.

What is the scale of the tuberculosis (TB) problem?

Although effective treatment has been available for more than 70 years, TB is the leading cause of death from an infectious disease worldwide. The World Health Organization (WHO) estimates that more than one-third of the world’s population is infected with Mycobacterium tuberculosis. TB continues to be a significant disease due to factors such as immigration, the emergence of drug-resistant TB strains, HIV, and other conditions that weaken the immune system.

How can I be screened for TB?

There are two types of tests that screen for TB infection: the tuberculin skin test (TST or PPD) and blood tests such as the T-SPOT.TB test. The tuberculin skin test has been around for over 100 years. The T-SPOT.TB test is a blood test that was approved by the FDA in 2008. This test is particularly important for those who have had the TB vaccination, also known as the BCG vaccination, or for those who are immunocompromised.*

*Always consult your doctor for additional advice. For more information visit www.tspot.com or www.cdc.gov.

TB Test Services with T-Spot.TB - the EASY blood test for the detection of tuberculosis. 

The T-SPOT.TB test is a blood test for tuberculosis (TB) screening performed in one visit, using one blood collection tube.

Tuberculin Skin Test T-SPOT®.TB Test
How is the test administered?
Injection into the skin on the
inner surface of the forearm
Blood sample is taken
How is the test read?
Return to the office/clinic 48 -72 hours after administration Test is performed by a
laboratory that reports the
result to your doctor/clinic
How many visits are required?
Two One
What if I’ve had the BCG vaccine?
Accuracy of the test may be affected  Accuracy of the test is not affected

What happens if my test result is positive?

A positive test may mean that you have either latent or active TB. Your doctor will advise you on whether any additional testing, such as a chest x-ray, is needed. 



My Lab ReQuestTM

Order Tests without a doctor's order.

Pay at Time of Service

Pay a discounted rate for many laboratory services when paying at the time of service.