Tuberculosis (TB) Test by Lifelabs

QuantiFERON®–TB Gold Plus (QFT-Plus) is a simple blood test for Tuberculosis (TB), an air-born and highly contagious infectious disease. While TB most frequently affects the lungs (pulmonary TB) it can also cause diseases in any part of the body, such as the lymph nodes, bones, brain, organs, and eyes. TB is a serious disease that kills about 1.5 million people each year worldwide. TB is spread when a person with active, infectious TB disease coughs, sneezes, or spits, releasing droplets containing TB bacteria into the air, which are then inhaled by someone else.

What is Latent TB?

 

Not everyone who is exposed to TB bacteria will develop an infection, and not all of those who become infected will develop symptoms of TB disease, which is why getting tested is so important. Those who are infected but have no symptoms are said to have a latent TB infection (LTBI), while those who do become sick have an active infection.

 If you have latent TB, you do not feel sick but you could become sick at some point if your LTBI becomes an active TB infection. This happens to about 10% of people with untreated latent TB infections, who are otherwise in good health. A greater percentage of people with compromised immune systems, such as those suffering from malnutrition, tobacco users, those with diabetes, and especially those with HIV infection, are at greater risk of developing active TB disease. 

What makes QFT-Plus better than the skin test?

With the QFT test, you only need to visit LifeLabs once to give a blood sample. With the skin test, you need to plan two visits to your healthcare provider: one to administer the test and one to check for results. The QFT-Plus test is better at helping your healthcare provider determine if you have TB, saves you time, and provides more accurate results than traditional skin prick testing.  There are no risks to getting this test done. All you need to do is get blood drawn at a select LifeLabs location in your province.

Who should have the QFT-Plus test?

 

QFT-Plus can be used in place of the skin test and is suitable for anyone who has:

 

1. Had contact with someone known to have TB
2. Been to a country with high rates of TB
3. A weak immune system, such as:
1. Those with HIV infection
2. Those with chronic underlying conditions, including diabetes and kidney disease
3. Organ transplant recipients and others on immunosuppressant drugs
4. Pregnant women
5. The elderly
4. Started some types of medications
   

 

Additionally, people who work with, or are part of groups with high rates of infection, such as IV drug users, or confined populations, such as hospitalized patients, prisoners, and residents of nursing homes can also use this test. QFT-Plus works in people who have been previously vaccinated against TB, and can also be used to confirm a positive skin test result.

How can I get the QFT-Plus test?

 

QFT is available at select LifeLabs locations in Ontario and BC. You must bring a completed test requisition from your healthcare provider.

What will the test show?

 

The QFT-Plus test will help your healthcare provider determine if you have TB. It will show one of two results:

 

• Positive – you will probably have TB. However, your healthcare provider needs to see you before confirming that you have TB
• Negative- you probably do not have TB.
  

 

Occasionally, the results are not clear. If that happens, your healthcare provider may have you take the test again.