What if my QuantiFERON TB Gold is positive?
What is the treatment for a positive TB test?
Does QuantiFERON go away after treatment?
What is the treatment for latent TB infection?
Should I take medicine for latent TB?
Can latent TB go away by itself?
Will I always test positive for latent TB after treatment?
Can lungs heal after TB?
Is latent TB Serious?
TB disease is very serious. TB disease can kill you. Even if you feel okay now, you must take the medicine your health care provider has prescribed and follow your health care provider's instructions. That's the only way to beat TB.
What is the fastest way to cure TB?
How long does latent TB treatment last?
What Are The Advantages of The QuantiFERON-TB Gold Blood Test?
This blood test can measure active and latent TB infections, but only in adult patients. The TST is still considered the standard for children. Onl...
Who Should Not Take The QuantiFERON-TB Gold Blood Test?
Besides children, there are certain population groups that are not considered viable candidates for taking this blood test. Anyone who has an alter...
What Do The Results Mean?
The QuantiFERON-TB Gold blood test will come back with either a positive or a negative result. In some people, an inconclusive result may occasiona...
What is QFT-G?
On May 2, 2005, a new in vitro test, QuantiFERON ® -TB Gold (QFT-G, manufactured by Cellestis Limited, Carnegie, Victoria, Australia), received final approval from the U.S. Food and Drug Administration ( FDA) as an aid in diagnosing Mycobacterium tuberculosis infection, including both latent tuberculosis infection (LTBI) and tuberculosis (TB) disease. This enzyme-linked immunosorbent assay (ELISA) test detects the release of interferon-gamma (IFN-g) in fresh heparinized whole blood from sensitized persons when it is incubated with mixtures of synthetic peptides simulating two proteins present in M. tuberculosis: early secretory antigenic target--6 (ESAT-6) and culture filtrate protein--10 (CFP-10). ESAT-6 and CFP-10 are secreted by all M. tuberculosis and pathogenic M. bovis strains. Because these proteins are absent from all Bacille Calmette-Guérin (BCG) vaccine strains and from commonly encountered nontuberculous mycobacteria (NTM) except M. kansasii, M. szulgai, and M. marinum ( 1 ), QFT-G is expected to be more specific for M. tuberculosis than tests that use tuberculin purified protein derivative (PPD) as the antigen.
When to use QFT-G?
QFT-G can be used in all circumstances in which the TST is used, including contact investigations, evaluation of recent immigrants who have had BCG vaccination, and TB screening of health-care workers and others undergoing serial evaluation for M. tuberculosis infection.
Can QFT-G be used in place of TST?
tuberculosis infection. QFT-G usually can be used in place of (and not in addition to) the TST.
What is a TST test?
The tuberculin skin test [TST] is implanted just under the skin and then sits for a predetermined amount of time. The reaction to the TST is then judged by the care provider to determine if the result is positive, negative, or inconclusive.
Can TB be fatal?
TB, when it isn’t treated right away, can become a fatal disease. Even when it isn’t fatal, tuberculosis can cause a lung infection, spread to the kidneys, and even affect the brain. Spread through droplets that come from the respiratory system, like with a sneeze, it can be spread from person to person quite easily.
Can pregnant women get a blood test?
Women who are pregnant are also not considered good candidates for this blood test. The CDC, however, has approved the use of this blood test as a screening tool for virtually all individuals based on current data, even if the results from the test have not been studied.
What does a negative test mean?
A negative result means that there is not active or latent tuberculosis infection. A positive result is an indication that there is an infection that is present and that follow-up treatment may be necessary. An inconclusive test is generally cause by a laboratory error or a blood sample that has sat for too long.
How long does it take for blood work to be processed?
The one issue that may present itself for some people is that blood test results must be processed within 12 hours of collection in order for the test to be accurate. For medical providers that must ship out blood draws to a laboratory for this test, it may be impossible for the sample to reach the lab in time.
What does it mean if your TST is positive?
If your TST (Mantoux) or Quantiferon blood test was found to be positive, this means you have a latent TB infection, but usually not the active disease.
Can you breathe in TB?
Tuberculosis infection occurs when you breathe in TB bacteria while you are exposed to someone who has active TB in their lungs. Usually, the body’s defences control the infection, but the bacteria can remain in the body for years in an inactive or ‘latent’ state. There is a small risk of developing TB disease (active TB) sometime later in life.
How many people do not develop active TB?
About 90 per cent of people will not develop the active disease. People with TB infection: usually have a normal chest X-ray. If taken correctly, preventative treatment can significantly reduce the risk of people with the latent TB infection developing the active TB disease.
What causes yellow eyes?
skin rashes, bruising or yellow skin. upset stomach, nausea, vomiting, diarrhoea or loss of appetite. lack of feeling or tingling in the hands or feet. changes in your eyesight, particularly changes in red or green colour vision. dark coloured urine. yellow eyes.
Is LTBI a common misconception?
No, this is a common misconception. 1 in 3 people worldwide is thought to be infected with LTBI, (4) although there is significant variance in high incidence countries based on the demographics of the population being studied.
What is remote infection?
The term remote infection is an ill-defined term that is increasingly being used in the TB community. For most, it appears that remote infection relates to old TB infection that may have been cleared by the individual, however, some may interpret it as meaning old TB infection that can still reactivate to TB disease.
How many people are infected with LTBI?
With an estimated 2 billion people (or one third of the world’s population) infected, the large global reservoir of LTBI represents a huge pool of contagious disease. Diagnosing LTBI, and preventive treatment, can significantly reduce the risk of disease, and prevent outbreaks from recent transmission.
What is QFT test?
QFT is an in vitro laboratory diagnostic test using a whole blood specimen. It is intended for use as a diagnostic aid for M. tuberculosiscomplex infection, whether active tuberculosis disease or LTBI, and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations.
Is QFT more sensitive than TST?
Studies suggest that QFT is more sensitive and specific than the TST for detecting M. tuberculosisinfection in HIV positive people (19–21). In an HIV / TB co-infected population, the sensitivity of QFT is 63–85% compared to 15–46% for the TST (22, 23).
How long does it take for a blood sample to be processed?
Blood samples must be processed within 8-30 hours after collection while white blood cells are still viable. Errors in collecting or transporting blood specimens or in running and interpreting the assay can decrease the accuracy of IGRAs.
What is the diagnosis of LTBI?
A diagnosis of LTBI requires that TB disease be excluded by medical evaluation. This should include checking for signs and symptoms suggestive of TB disease, a chest radiograph, and, when indicated, examination of sputum or other clinical samples for the presence of M. tuberculosis.
Background
Methodology
- During July 11--12, 2005, CDC convened a meeting in Atlanta, Georgia, of consultants and researchers with expertise in the field to review studies and assess experience with QFT-G. Unpublished data from studies of QFT-G were considered in preparing these guidelines. Expert consultants (see Membership List), researchers, TB control public health practitioners, and repre…
Indications For QFT-G
- FDA approved QFT-G as an in vitrodiagnostic aid using peptide mixtures simulating ESAT-6 and CFP-10 proteins to stimulate cells in heparinized whole blood. Detection of IFN-g by ELISA is used to identify in vitro responses to ESAT-6 and CFP-10 that are associated with M. tuberculosis infection (12). From a medical and public health perspective, QFT-G testing is indicated for diag…
How QFT-G Testing Is Performed and Interpreted
- Instructions for the QFT-G assay are in the package insert (13). Aliquots of heparinized whole blood are incubated with the test antigens for 16--24 hours. The blood must be incubated with the test antigens <12 hours after collection. Test kits include two mixtures of synthetic peptides representing ESAT-6 and CFP-10 as test antigens, phytohemaglut...
Cautions and Limitations
- Certain limitations of QFT-G are similar to those of the TST, but these limitations have not been studied extensively for QFT-G. Whereas the sensitivity of QFT-G for detecting M. tuberculosis infection in persons with untreated culture-confirmed TB is approximately 80% in published studies (5,8), its sensitivity for particular groups of TB patients (e.g., young children and immuno…
Future Research Needs
- Additional studies to assess the performance of the QFT-G test under program conditions should be conducted. Further research is needed regarding use of QFT-G in multiple clinical circumstances. Studies of test performance should assess specificity, sensitivity, reproducibility, and association of test results with risk for infection and risk for progressing to TB disease. Co…