The Genexpert test diagnoses TB by finding out the TB bacteria, as well as evaluating resistance to the drug Rifampicin. This test is fully automated and can detect bacilli faster as compared to standard methods which find out bacteria growth in 4-5 weeks and take extra 2-3 weeks for drug resistance testing. The details given by the Xpert MTB/RIF assay helps in deciding the treatment procedure to be taken.
Here are a few important things you need to know about the Genexpert test:
How does this test work?
It is a nucleic acid amplification (NAA) test that applies a disposable cartridge with the Genexpert tool or system. In this procedure, a sputum sample is collected from the person suspected of TB. Later, the sputum is combined with the reagent, offered with the assay, and a cartridge having this mix is kept in the Genexpert machine. All the processes from this point till the end are completely automated.
Reasons why this test is performed
The Xpert MTB/RIF assay is done to ensure fast detection of TB for those who need instant treatment as other standard tests take several weeks to show the results. So, rather than waiting for many days for the test results, the Genexpert gives faster results for patients, helping them to start the treatment on time.
Advantages of Xpert MTB/RIF assay
Some of the most important benefits of using this test procedure include:
- Test results are available promptly, mostly on the same day
- Minimum technical training is needed to carry out the process
- No special preparations are needed for the test
- The test can be carried out on both pulmonary as well as extrapulmonary samples
- The Genexpert test can be done on both negative and positive samples of AFB smear
- The process also diagnose Rifampicin resistance (rpoB gene) which is the substitute creator for MDRTB
- The specificity of the Xpert MTB/RIF assay is 99%, means accurate results
When is the test prescribed?
The Xpert MTB/RIF assay test is quite specific, sensitive, and quick for diagnosing TB and antibiotic resistance. In case the doctor suspects that the patient is suffering from TB and looks for immediate detection to start an effective treatment, he or she prescribes this test.
Genexpert test is prescribed for fast and confirmatory molecular detection of tuberculosis. It is highly specific (98%) and sensitive (88%) and it can:
- Prevent delays in detection and start of treatment
- Find out Rifampicin resistance (diagnose rpoBgene mutation)
- Aid in choosing the right antitubercular medication
The use of the Genexpert test
The test is recommended by WHO to be used as the initial diagnosis procedure in people suspected of HIV associated TB or MDR TB. However, WHO has emphasised that this test cannot replace traditional microscopy culture and drug sensitivity tests, as these procedures are still needed to find out other kinds of drug resistance and monitor the treatment progress. The Genexpert MTB/RIF method cannot be applied for screening or observing the treatment since it detects dead and live bacteria.
To ensure the accuracy and on-time results, people should choose the best lab in Chennai, Delhi, Gurgaon, Mumbai, or any other city India.