The test might show you don’t have TB when you do, especially if you were exposed a long time ago and your immune response to it is weak. Or you could get a false positive result if you’ve been vaccinated with the TB bacillus Calmette-Guerin (BCG) vaccine.
Likewise, people ask, are false-positive TB tests common?
In 18 studies involving 1,169,105 subjects, the absolute prevalence of false-positive TST from NTM cross-reactivity ranged from 0.1% to 2.3% in different regions. Conclusions: The effect on TST of BCG received in infancy is minimal, especially > or =10 years after vaccination.
Similarly one may ask, how accurate is the blood test for tuberculosis?
“A blood test for diagnosing active TB disease is bad practice. Test results are inconsistent, imprecise and put patients’ lives in danger.” Today’s policy recommendation applies to blood tests for active TB. Blood tests for inactive TB infection (also known as dormant or latent TB) are currently under review by WHO.
What can cause false-positive QuantiFERON gold?
(1) False-positive results may occur in patients with prior infection with M marinum, M szulgai, or M kansasii. Negative: No IFN-gamma response to M tuberculosis antigens was detected. Infection with M tuberculosis is unlikely.
What can TB be mistaken for?
It is not uncommon for pulmonary tuberculosis (TB) to be misdiagnosed as pneumonia, particularly in the acute phase when they both present identically. Between five and ten per cent of infected people not receiving treatment for latent TB infection will develop TB during their lives.
What is the false-positive rate for TB blood test?
3, left panel), confirmatory testing even at a threshold of 0.35 IU/mL reduced the ten-year false positive percentage from 24.6% to 4.1% (95%UR: 3.7–4.5%).