A positive TB test result isn't automatically "bad," but it does require further investigation. It signifies the presence of Mycobacterium tuberculosis bacteria in your body, indicating either a latent TB infection (LTBI) or active TB disease. However, a positive result can also occur due to a prior TB vaccination.
Understanding the Implications of a Positive TB Test
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Latent TB Infection (LTBI): This means you've been infected with the TB bacteria, but your immune system is currently controlling it. You aren't contagious and generally don't experience symptoms. However, LTBI can progress to active TB disease if left untreated.
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Active TB Disease: This is the serious form of the infection where the bacteria are actively multiplying and causing illness. Active TB is contagious and requires immediate treatment to prevent further spread and complications. Symptoms can include a persistent cough, fever, night sweats, and weight loss.
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False Positives: A positive test result can sometimes be a false positive, particularly in individuals who have received the BCG (Bacillus Calmette-Guérin) vaccine against TB. The vaccine can trigger a positive result even in the absence of infection.
Therefore, a positive TB test is a signal for further evaluation, not a diagnosis. Additional tests, such as chest X-rays and sputum cultures, are typically needed to determine whether you have latent TB infection or active TB disease. Early diagnosis and treatment are crucial for preventing the progression of LTBI to active TB and containing the spread of active TB.
The sources cited emphasize that a positive test doesn't definitively mean active TB. Further testing is essential to determine the actual status of the infection. A negative test, conversely, doesn't guarantee the absence of infection; additional tests might be needed if symptoms are present.
