Tuberculosis (TB) is an infectious disease caused by the bacteria Mycobacterium tuberculosis. It primarily affects the lungs but can also affect other parts of the body. Early detection and treatment are crucial in controlling the spread of the disease.
One quick test for TB is the tuberculin skin test, also known as the Mantoux test. This test involves injecting a small amount of tuberculin into the skin and checking for a reaction within 48 to 72 hours. A positive reaction indicates that the person has been exposed to the TB bacteria. However, this test does not differentiate between active and latent TB infections.
Another quick test for TB is the interferon-gamma release assay (IGRA) blood test. This test measures the immune response to TB bacteria by detecting the production of a specific protein in response to the bacteria. It is more specific than the tuberculin skin test and can help differentiate between active and latent TB infections.
Both tests have their limitations, and a definitive diagnosis of TB usually requires further testing, such as sputum samples or chest x-rays. It is important to consult a healthcare provider if you suspect you have been exposed to TB or are experiencing symptoms such as cough, fever, and weight loss. Early detection and treatment are key in preventing the spread of TB and improving patient outcomes.
How quickly can you test for TB?
The skin test reaction should be read between 48 and 72 hours after administration by a health care worker trained to read TST results. A patient who does not return within 72 hours will need to be rescheduled for another skin test. The reaction should be measured in millimeters of the induration (firm swelling).
What is the rapid diagnostic test for TB?
People diagnosed with TB using rapid molecular tests recommended by WHO (1), lateral flow urine lipoarabinomannan (LF-LAM) assays, sputum smear microscopy or culture are defined as “bacteriologically confirmed” cases of TB (2).
How accurate is the TB rapid test?
Sensitivity of NAATs, using culture as a gold standard test, is 95% in smear-positive patients (6, 7) and varies between 50–80% in smear-negative patients (4, 8). Although the specificity of NAATs is quite high (6, 18) but it has not been recommended for routine TB diagnosis due to its inconsistent accuracy (8, 9).
What is the fastest test for TB?
A normal sputum culture can take 1 to 8 weeks to provide results. A rapid sputum test can tell if a person has TB within 24 hours.
