Search results
Results From The WOW.Com Content Network
Even if sputum smear is negative, tuberculosis must be considered and is only excluded after negative cultures. [ citation needed ] Nucleic acid amplification tests (NAAT) for TB are a heterogeneous group of tests that use either the polymerase chain reaction (PCR) technique or transcription-mediated amplification (TMA) or other forms of ...
A false negative result may occur in a person who has been recently infected with TB, but whose immune system hasn't yet reacted to the bacteria. Upper respiratory virus infection In case a second tuberculin test is necessary it should be carried out in the other arm to avoid hypersensitising the skin.
Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, [7] is a contagious disease usually caused by Mycobacterium tuberculosis (MTB) bacteria. [1] Tuberculosis generally affects the lungs , but it can also affect other parts of the body. [ 1 ]
Negative reaction to tuberculin skin test 1: TB exposure No evidence of infection: History of exposure Negative reaction to tuberculin skin test 2: TB infection No disease: Positive reaction to tuberculin skin test Negative bacteriologic studies (if done) No clinical, bacteriologic, or radiographic evidence of TB 3: TB, clinically active
However, when Xpert TB was used as an add-on for cases of negative smear microscopy the sensitivity was only 67% and specificity 99%. [9] In a clinical study conducted the sensitivity of the MTB/RIF test on just 1 sputum sample was 92.2% for culture-positive TB; 98.2% for smear+ and culture-positive cases; and 72.5% for smear-negative, culture ...
Mycobacterium tuberculosis that causes tuberculosis (TB) in humans is an airborne bacterium that typically infects the human lungs. [6] [7] Testing for TB includes blood testing, skin tests, and chest X-rays. [8] When looking at the smears for TB, it is stained using an acid-fast stain.
Grade 1 – four to six papules (also considered negative) Grade 2 – confluent papules form indurated ring (positive) Grade 3 – central filling to form disc (positive) Grade 4 – disc >10 mm with or without blistering (strongly positive) Grades 1 and 2 could result from previous BCG or avian tuberculosis, rather than human TB infection.
If there is any question of active TB, sputum smears must be obtained. Therefore, any applicant might have findings grouped in this category, but still have active TB as suggested by the presence of signs or symptoms of TB, or sputum smears positive for AFB. [2] The main chest X-ray findings that can suggest inactive TB are: [2] 1.