Discordant line probe genotypic testing vs culture-based drug susceptibility phenotypic testing in TB endemic KwaZulu-Natal: Impact on bedside clinical decision making

Sharana Mahomed*, Koleka Mlisana, Lindiwe Cele, Kogieleum Naidoo

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The recommendations for Mycobacterium tuberculosis drug susceptibility testing include both phenotypic and genotypic methods. This concurrent use of differing testing platforms has created an emerging challenge of discordant results, creating a diagnostic dilemma for the laboratorians as well as attending clinicians. We undertook a retrospective study to determine the prevalence of discordant results between the MTBDRplus line probe assay and solid culture-based drug susceptibility testing for rifampicin and isoniazid. The analysis was conducted for the period January 2013 and December 2015 at the Inkosi Albert Luthuli Central Hospital. Rifampicin and isoniazid resistance testing data were “paired” on 8273 isolates for culture-based drug susceptibility testing and line probe assay. The latter method showed high sensitivity and specificity of 93% and 95% respectively for isoniazid testing. For rifampicin testing, sensitivity and specificity were 95% and 75%. Overall, discordance was 14.6% for rifampicin and 7.2% for isoniazid. This report is not intended to determine superiority of one method over another. It is merely to show that discordance does exist between different methods of testing. Given the burden of HIV and Tuberculosis in Sub-Saharan Africa, these findings have clinical significance and huge public health implications. Clinicians should understand the limitations of phenotypic testing methods.

Original languageEnglish
Article number100176
JournalJournal of Clinical Tuberculosis and Other Mycobacterial Diseases
Volume20
DOIs
Publication statusPublished - Aug 2020

Keywords

  • Culture
  • Discordance
  • Drug susceptibility testing
  • Line probe assay
  • Mycobacterium tuberculosis

Fingerprint

Dive into the research topics of 'Discordant line probe genotypic testing vs culture-based drug susceptibility phenotypic testing in TB endemic KwaZulu-Natal: Impact on bedside clinical decision making'. Together they form a unique fingerprint.

Cite this