Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Dec 6;7(2):806.
doi: 10.4102/ajlm.v7i2.806. eCollection 2018.

Diagnosis of rifampicin-resistant tuberculosis: Discordant results by diagnostic methods

Winnie Mwanza  1 , Deborah Milimo  1 , Maureen M Chilufya  1 , Nkatya Kasese  1 , Maina C Lengwe  1 , Stembiso Munkondya  1 , Petra de Haas  1   2 , Helen Ayles  1   2 , Monde Muyoyeta  1
Affiliations

Diagnosis of rifampicin-resistant tuberculosis: Discordant results by diagnostic methods

Winnie Mwanza et al. Afr J Lab Med. .

Abstract

The performance of the Xpert© MTB/RIF and MTBDRplus assays for the detection of rifampicin resistant Mycobacterium tuberculosis was compared to culture-based drug susceptibility testing in 30 specimens with rifampicin-resistant and rifampicin-indeterminate Xpert MTB/RIF results collected between March 2012 and March 2014. Xpert MTB/RIF and MTBDRplus were 100% sensitive and 100% concordant for rifampicin resistance detection, but 3 of 13 samples (23%) positive for rifampicin resistance on Xpert MTB/RIF and MTBDRplus were negative for rifampicin resistance on mycobacteria growth indicator tube drug susceptibility testing. Specificity was 72% for Xpert MTB/RIF and 80% for MTBDRplus. Positive predictive value for Xpert MTB/RIF for multidrug resistant tuberculosis was 47.8% for new patients and 77.8% for previously treated patients; negative predictive value was 100% for both new and previously treated patients. The discordant rifampicin resistance test results indicate a need to fully characterise circulating rifampicin resistant Mycobacterium tuberculosis strains in Zambia and to inform the development of guidelines for decision-making in relation to diagnosis of drug-resistant tuberculosis.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no financial or personal relationships which may have inappropriately influenced them in writing this article.

References

    1. World Health Organization Policy statement: Automated real-time nucleic acid amplification technology for rapid and simultaneous detection of tuberculosis and rifampicin resistance. Geneva: WHO; 2011. - PubMed
    1. World Health Organization Policy statement. Molecular line probe assays for rapid screening of patients at risk of multidrug resistant tuberculosis (MDR-TB) [homepage on the Internet]. [cited 2008 June 27]. Available from: http://www.who.int/tb/features_archive/policy_statement.pdf
    1. Siu GK, Zhang Y, Lau TCK, et al. . Mutations outside the rifampicin resistance-determining region associated with rifampicin resistance in Mycobacterium tuberculosis. J Antimicrob Chemother. 2011;66(4):730–733. https://doi.org/10.1093/jac/dkq519 - DOI - PubMed
    1. Jamieson FB, Guthrie JL, Neemuchwala A, et al. . Profiling of rpoB mutations and MICs for rifampin and rifabutin in Mycobacterium tuberculosis. J Clin Microbiol. 2014;52(6):2157–2162. https://doi.org/10.1128/JCM.00691-14 - DOI - PMC - PubMed
    1. Horng YT, J W-Y, Chen Y-Y, et al. . Molecular analysis of codon 548 in the rpoB gene involved in Mycobacterium tuberculosis resistance to rifampin. Antimicrob Agents Chemother. 2015;59(3):1542–1548. https://doi.org/10.1128/AAC.04374-14 - DOI - PMC - PubMed

LinkOut - more resources