The xpert mtbrif assay is a nucleic acid amplification naa test that uses a disposable. Tuberculosis tb remains the leading cause of morbidity and mortality worldwide that is caused by mycobacterium tuberculosis mtb. The stable indicators evaluated in the genexpert test showed that it is a useful test especially in extralung samples of patients with hivaids. Genexpert for diagnosis of tubercular meningitis springerlink.
This is done by ensuring welltrained maintenance of genexpert instruments, and making sure that there is a database of people who are trained in troubleshooting, machine calibrations, installation and problemsolving, either onsite or remote. The xpert mtbrif purifies and concentrates mycobacterium tuberculosis bacilli from sputum samples. The sensitivity, specificity, ppv and npv of genexpert and zn microscopy were calculated using liquid culture of. Who stop tb department has issued a policy statement and further information on the new rapid tb test that was endorsed by who in december 2010. Use of genexpert mycobacterium tuberculosisrifampicin for. Tuberculosis tb due to mycobacterium tuberculosis mtb remains a major public health issue. The genexpert mtbrif assay has been recommended by who in 20 to be used in children and in extra pulmonary clinical specimens. Xpert method for xpertmtbrif assay, allows rapid diagnosis of tuberculosis multiple drug resistance mycobacterium tuberculosis mtbmdrtb. In india, where this test is starting to be widely used, it is known as the cbnaat. For the first time, a molecular test is simple and robust enough to be introduced and used outside conventional laboratory settings. The xpert mtbrif is a cartridgebased nucleic acid amplification test naat for simultaneous rapid tuberculosis diagnosis and rapid antibiotic sensitivity test. The whos policy statement was supported by a rapid implementation document, which provided the technical howto and operational considerations for. We searched pubmed with the term xpert mtbrif ultra for articles in any language published until oct 18, 2017. The genexpert diagnoses tb by detecting the presence of tb bacteria, as well as testing for resistance to the drug rifampicin.
Xpert negative or acidfast bacilli afb smearnegative sputum may contain viable organisms and. Mar 24, 2016 tuberculosis tb is the most common infectious disease worldwide caused by mycobacterium tuberculosis mtb. Who xpert mtbrif rapid tb test who publishes policy. Most infections show no symptoms, in which case it is known as latent tuberculosis. The mean time for the obtention of a positive result was 34 days for the culture in the lowestein jensen media,14 for the mgit media, and 2. Containment of bioaerosol infection risk by the xpert mtb.
The genexpertmtbrif xpert assay is now recommended by who for diagnosis of tuberculosis tb in children but evaluation data is limited. Division of tuberculosis elimination a new tool to diagnose tuberculosis. Comparative study of genexpert with zn stain and culture. The rapid, fullyautomated naat nucleic acid amplification test also known as xpert mtbrif assay has been described as a major breakthrough in tb. Genexpert xpert mtbrif in multidrug resistant tuberculosis. Rapid molecular detection of extrapulmonary tuberculosis.
Genexpert xpert mtbrif in multidrug resistant tuberculosis by the health technology assessment study group health policy development and planning bureau key message tuberculosis in the philippines remains a public health priority. This possibility may be supported by the isolation of tb strains from alternative materials from these patients. Diagnosis of tubercular meningitis tbm is difficult in children. Using the who policy guidance and recommendations as a framework ephi conducted a national operational validation study on genexpert mtbrif assay with the objective of. Tuberculosis tb remains a major public health problem in the developing world, partly due to a steady increase in the frequency of mycobacteria tuberculosis strains becoming resistant to one or more of the first line antitb drugs. The xpert mtbrif detects dna sequences specific for mycobacterium tuberculosis and rifampicin resistance by polymerase chain reaction it is based on the cepheid genexpert system, a rapid, simpletouse nucleic acid amplification tests naat. An unprecedented uptake of this new technology followed the release of whos policy. The development of the xpert mtbrif assay for the genexpert platform was completed in 2009 and is considered an important breakthrough in the fight against tb. The xpert mtbrif assay is a new test that is revolutionizing tuberculosis tb control by contributing. Xpert mtb rif medical equipment pdf manual download. The genexpert assay is a realtime pcr test that will simultaneously identify m. The recently introduced xpert mtbrif assay cepheid, sunnyvale, ca simultaneously detects the presence of mycobacterium tuberculosis and its susceptibility to the important firstline drug rifampin rif in less than 2 h. Supporting the introduction of genexpert in nigeria kncv. It can find out if a person is infected with tb, and also if the tb bacterium of the person has resistance to one of the common tb drugs, rifampicin.
A comparative study between genexpert and smear microscopy for diagnosis of tuberculosis in paediatric patients dr nita sutay1, dr swati jha2, dr devanand chaudhary3 abstract. Use of the genexpert tuberculosis system for hiv viral load testing in india article pdf available in the lancet global health 58. Microscopy is the most available diagnostic technique but. In the global tb report 2014, who reported that in 20, nine million people developed tb. Banada,a srinidhi deshpande, shubhada shenai,a alexander gall,c jennifer glass,b barry krieswirth,d. The xpert mtbrif assay what is the xpert mtbrif assay. Other than two commentaries, we found two primary research articles describing the limit of detection and the performance of xpert ultra for detection of mycobacterium tuberculosis in cerebrospinal fluid. The genexpert mtbrif testtm used in the study of 693. The aim of this study is to evaluate the performance of the xpertmtbrif assay method in the diagnosis of mtb and drug resistance. The xpert mtbrif assay is a new test that is revolutionizing tuberculosis tb control by contributing to the rapid diagnosis of tb disease and drug resistance. This technology has good sensibility and even better specificity in respiratory. Xpert mtbrf is an automatic methodology that uses the polymerase chain reaction to detect in less than two hours the presence of mycobacterium tuberculosis and also informs about the sensibility. In india, where the genexpert is starting to be widely used, it is known as the cbnaat.
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. The genexpert mtbrif assay is potentially valuable for tb diagnosis in the majority of the ep and respiratory other than sputum samples in our setting. The accuracy of detection of drugresistance between the phenotypic dst and the xpert. In comparison, standard cultures can take 2 to 6 weeks for mtbc to grow and conventional drug resistance tests. 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. Although the genexpert mtbrif assay provides rapid diagnostic results, the overall sensitivity to rule out the disease is suboptimal for some specimen types. It is an automated diagnostic test that can identify mycobacterium tuberculosis mtb dna and resistance to rifampicin rif. Conventional cultures are highly sensitive consuming, whereas ziehl neelsen zn stain is a rapid method with high specificity but has lower sensitivity. Diagnosis of tuberculosis tb in children is challenging due to insufficient specimen material and the scarcity of bacilli in specimens. Pdf pdf icon 206k a new tool to diagnose tuberculosis. Mycobacterium tuberculosis complex showed resistance to rifampin or to the other antimicrobials studied. Baar in contrast to genexpert and culture, which reported positive in 94 78.
The full name of the cbnaat test is the cartridge based nucleic acid amplification. Tuberculosis tb is an infectious disease usually caused by mycobacterium tuberculosis mtb bacteria. The genexpert mtbrif assay is a novel integrated diagnostic device for the diagnosis of tuberculosis and rapid detection of rif resistance in clinical specimens. Simultaneamente detecta a mycobacterium tuberculosis y resistencia a rifampicina. Who has recommended starting rollout of the genexpert mtbrif system in specific settings to improve tb diagnosis and detection of rifampicin resistance. Contrary to the tests that exist at the moment, it works on a molecular level to identify mycobacterium tuberculosis.
The oldest descriptions of tb can be found in documents that were written more than 5000 years. Genexpert mtbrif assay is a nucleic acid amplification naa test which simultaneously detects dna of mycobacterium tuberculosis complex mtbc and resistance to rifampin rif i. Kncv supervises the oneday installation and training for new genexpert end users. R perteneciente al complejo mtb, aerobio estricto, resistente al frio y a. Tuberculosis continues to be a global public health problem, the extrapulmonary form being estimated to occur in 1020% of immunocompetent individuals, increasing in patients who are carriers of the human immunodeficiency virus hiv. Implementation guideline for genexpert mtbrif assay in. The xpert mtbrif assay is a nucleic acid amplification naa test that uses a disposable cartridge with the genexpert instrument system. Oct 03, 2011 the gene xpert is a new test for tuberculosis. Prospective evaluation of genexpert for the diagnosis of hiv. The rapid, fullyautomated naat nucleic acid amplification test also known as xpert mtbrif assay has been described as a. It is an automated diagnostic test that can identify mycobacterium tuberculosis. While the genexpert technology has been widely received in namibia, dsm is still widely used for the di.
Xpert is more sensitive than sputum smear microscopy in detecting tb, and it has similar accuracy as culture. At the same time, global burden of multidrugresistant tb mdrtb was estimated to be 480,000 cases leading to estimated 210,000 deaths. Improving detection of mycobacterium tuberculosis and resistance to rifampin in an assay suitable for pointofcare testing soumitesh chakravorty, aann marie simmons,b mazhgan rowneki, heta parmar,a yuan cao, ajamie ryan,b padmapriya p. A sputum sample is collected from the patient with suspected tb. Tuberculosis generally affects the lungs, but can also affect other parts of the body. The present study was designed to assess the diagnostic utility of genexpert in detecting mycobacterium tuberculosis in cerebrospinal fluid csf in tbm cases and to compare the results with liquid. Importantly, its ability to detect rifresistant tb in less than 2 hours significantly improves the likelihood of timely treatment initiation. Manual operativo implementacion del genexpert mtb rif en. Evaluation of genexpert mtbrif for the detection of. Evaluation of genexpert mtbrif for the detection of mycobacterium tuberculosis and resistance to rifampin in extra chema marouane a, salma sm fea. Tuberculosis tb is a wellknown infectious disease which has been a major health burden in human history and still is a major leading cause of death in developing countries1. The assay is very easy to perform and almost entirely automated, requiring only two manual steps. Pdf xpert mtbrif is a major advance for tb diagnostics, especially for multidrugresistant mdr tb and hivassociated tb. Tuberculosis y resistencia a farmacos antituberculosos.
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