Rapid and Accurate Detection of Mycobacterium tuberculosis in Sputum Samples by Cepheid Xpert MTB/RIF Assay—A Clinical Validation Study
2011

Rapid and Accurate Detection of Tuberculosis Using Xpert MTB/RIF Assay

Sample size: 292 publication 10 minutes Evidence: high

Author Information

Author(s): Rachow Andrea, Zumla Alimuddin, Heinrich Norbert, Rojas-Ponce Gabriel, Mtafya Bariki, Reither Klaus, Ntinginya Elias N., O'Grady Justin, Huggett Jim, Dheda Keertan, Boehme Catharina, Perkins Mark, Saathoff Elmar, Hoelscher Michael

Primary Institution: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany

Hypothesis

The Xpert MTB/RIF Assay is a rapid diagnostic test for detecting Mycobacterium tuberculosis in sputum samples.

Conclusion

The Xpert MTB/RIF Assay is a highly sensitive and specific method for diagnosing tuberculosis.

Supporting Evidence

  • The Xpert MTB/RIF Assay achieved 88.4% sensitivity among patients with a positive culture.
  • The assay showed 99% specificity in patients who had no TB.
  • HIV status did not affect test performance in 172 HIV-infected patients.
  • Seven additional cases were detected by the assay among culture-negative patients.
  • The assay's specificity was 97.8% in samples that grew non-tuberculous mycobacteria.

Takeaway

This study shows that a new test can quickly and accurately find tuberculosis in patients, which is really important for treating the disease.

Methodology

The study analyzed sputum samples from 292 adults suspected of having TB using the Xpert MTB/RIF Assay and compared results with standard sputum smear microscopy and culture.

Potential Biases

Potential bias due to the study being conducted in a specific geographic area with high TB and HIV prevalence.

Limitations

The study was conducted in a single location and may not be generalizable to all settings.

Participant Demographics

292 adults, mean age 39.2 years, 151 females and 141 males, with 58.9% being HIV-positive.

Statistical Information

P-Value

p<0.001

Confidence Interval

95%CI=78.4% to 94.9%

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1371/journal.pone.0020458

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