What is GeneXpert test for TB?

Introduction: Gene-Xpert, a CBNAAT (catridge based nucleic acid amplification test) is a widely accepted diagnostic test for Tuberculosis. This test is a rapid diagnostic test for Tuberculosis detection as well as Rifampicin resistance in direct smear negative cases.

Can GeneXpert detect active TB?

GeneXpert MTB/RIF can detect both the presence of the Mycobacterium tuberculosis complex genome in patient specimens and the presence of genomic sequences of the main mutations responsible for Rifampicin resistance (rpoB gene mutation).

How accurate is GeneXpert?

However PPV, NPV and Diagnostic accuracy of Gene XPERT test was 96.77%, 94.94% and 96.23% respectively. Conclusion: Hence it has been concluded through results of this study is that GeneXpert is more accurate and reliable than sputum smear microscopy in predicting pulmonary TB.

How is GeneXpert test done?

A sputum sample is collected from the patient with suspected TB. The sputum is mixed with the reagent that is provided with the assay, and a cartridge containing this mixture is placed in the GeneXpert machine. All processing from this point on is fully automated.

What is meant by GeneXpert?

The Genexpert diagnoses TB by detecting the presence of TB bacteria. The test is a molecular TB test which detects the DNA in TB bacteria. It uses a sputum sample and can give a result in less than 2 hours. The Genexpert can also detect the genetic mutations associated with resistance to the drug Rifampicin.

What is the principle of GeneXpert?

10 Cepheid GeneXpert system is innovative semi-automated real-time polymerase chain reaction (PCR) nucleic acid amplification technology, which can simultaneously detect MTB and Rifampicin (RIF) resistance in less than 2 hours.

Is GeneXpert a PCR test?

The GeneXpert Instrument Systems automate and integrate sample preparation, nucleic acid extraction and amplification, and detection of the target sequences in simple or complex samples using real-time PCR assays.

What is the gold standard for diagnosing TB?

The diagnostic gold standard for active tuberculosis (TB) is the detection of Mycobacterium tuberculosis (MTB) by culture or molecular methods. However, despite its limited sensitivity, sputum smear microscopy is still the mainstay of TB diagnosis in resource-limited settings.

How long is GeneXpert positive?

show that after the completion of appropriate treatment, GeneXpert can produce false-positive results for up to 4 years and in 8.72% of positive tests on respiratory samples for up to 18 months, possibly due to both the presence of residual mycobacterial DNA in the respiratory tract and the detection of non-viable …

What is the sample for GeneXpert?

The Genexpert diagnoses TB by detecting the presence of TB bacteria. The test is a molecular TB test which detects the DNA in TB bacteria. It uses a sputum sample and can give a result in less than 2 hours.

What is the best test to detect TB?

The Mantoux tuberculin skin test (TST) or the TB blood test can be used to test for M. tuberculosis infection. Additional tests are required to confirm TB disease. The Mantoux tuberculin skin test is performed by injecting a small amount of fluid called tuberculin into the skin in the lower part of the arm.

What is LPA in TB diagnosis?

Given the global situation of MDR-TB and an urgent need for detection of drug resistance amongst TB patients, line probe assay (LPA) was introduced. It is used for diagnosis of drug-resistant TB under programmatic conditions2. Only sputum samples that are smear positive for acid-fast bacilli (AFB) are tested by LPA.

What is gene Xpert test for TB?

The Genexpert test is a molecular test for TB which diagnoses TB by detecting the presence of TB bacteria , as well as testing for resistance to the drug Rifampicin. In India, where this test is starting to be widely used, it is known as the CB-NAAT .

Where can I get TB test near me?

You can get a skin test at the health department or at your doctor’s office. A healthcare worker will inject a small amount of testing fluid (called tuberculin or PPD) just under the skin on the underside of the forearm.

What are the guidelines for TB testing?

The standard recommended tuberculin test is the Mantoux test , which is administered by injecting a 0.1 mL of liquid containing 5 TU (tuberculin units) PPD (purified protein derivative) into the top layers of skin of the forearm. Doctors should read skin tests 48-72 hours after the injection.

What is an annual TB test?

A tuberculosis test, also known as a TB or PPD test , is a skin test that determines if someone has developed an immune response to a bacteria that causes tuberculosis. TB is a common disease that kills more than three million people worldwide each year and will often affect the lungs and almost any other organ in the body.