A suggested algorithm for detection of multi drug-resistant tuberculosis in Zimbabwe

MDR-TB detection in resource limited settings

  • Beauty Makamure Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe
  • Salome Makumbirofa Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe
  • Tsitsi Bandason Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe
  • Paul Leccese University of Colorado School of Medicine, Aurora, Colorado, United States
  • Reggie Mutetwa Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe
  • Val Robertson University of Zimbabwe, Harare, Zimbabwe
  • Peter Mason Biomedical Research and Training Institute (BRTI)

Abstract

Introduction: Rapid genotypic and phenotypic methods for multi-drug-resistant-tuberculosis (MDR-TB) detection are now widely available. Zimbabwe adopted the use of GeneXpert-MTB/RIF, microscopic-observation-drug-susceptibility-assay (MODS) and Mycobacteria-Growth-Indicator-Tube (MGIT) drug-susceptibility-testing (DST). Data is limited on the ideal combination of use of these methods in resource limited settings.


Methodology: Between August 2014 to July 2015, 211 sputa from MDR-TB suspects were tested with GeneXpert-MTB/RIF, MODS, manual-MGIT and Lowenstein-Jensen (LJ)-DST to determine diagnostic accuracy and turnaround-time (TAT), with LJ-DST as the gold standard. A performance score ranking table for diagnostic accuracy, TAT, costs, facilities and expertise requirements, was used to determine the most favourable tool.


Results: GeneXpert-MTB/RIF sensitivity was 96% (95%CI:80-100) and specificity was 95% (95%CI:90-97). MODS sensitivity was 88% (95%CI:68-97) and specificity was 97% (95%CI:87-100). Manual MGIT-DST had slightly lower sensitivity of 80% (95%CI:59-93). Median time to detection of MDR-TB was <1 day (IQR:0-0) for Xpert, 14 days (IQR:11-31) for MODS, 21 days (IQR:7-22) for MGIT-DST and 28 days (IQR:25-28) for LJ-DST. Operational costs for MODS, MGIT-DST, and GeneXpert-MTB/RIF were $21.20, $27.52 and $39.76 respectively. From a summation of scores including facility and expertise requirements per diagnostic technique, GeneXpert-MTB/RIF was the most favourable tool, followed by MODS and MGIT-DST.


Conclusions: For best scale-up of MDR-TB diagnosis in Zimbabwe, GeneXpert-MTB/RIF can be used for rapid detection of TB in smear negative cases, RIF-susceptibility for early treatment initiation and probable MDR-TB. MODS can rapidly confirm probable MDR-TB detected by GeneXpert-MTB/RIF, manual-MGIT can provide early results for susceptibility to other antibiotics, with affordable costs, with LJ-DST confirming discordant DSTs.

Author Biographies

Beauty Makamure, Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe

Medical Laboratory Scientist  with BRTI and a Master of Philosophy student with the University of Zimbabwe. I am 53 years old with 27 years hands on experience in laboratory technology. I have been involved in research work to do with Tuberculosis and Human Immunodeficiency Virus (HIV) since 2000.

Currently I am managing  BRTI laboratories.

Salome Makumbirofa, Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe

BRTI Projects Coordinator,

Tsitsi Bandason, Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe

BRTI Bio Statistician

Paul Leccese, University of Colorado School of Medicine, Aurora, Colorado, United States

University of Colorado School of Medicine Student

Reggie Mutetwa, Biomedical Research and Training Institute (BRTI), Harare, Zimbabwe

BRTI Research Scientist

Val Robertson, University of Zimbabwe, Harare, Zimbabwe

Department of Medical Microbiology, Associate Professor

President of Infection Control Association of Zimbabwe, and Secretary Infection Control Africa Network (ICAN)

Peter Mason, Biomedical Research and Training Institute (BRTI)
BRTI Director General
Published
2017-09-05
How to Cite
Makamure B, Makumbirofa S, Bandason T, Leccese P, Mutetwa R, Robertson V, Mason P (2017) A suggested algorithm for detection of multi drug-resistant tuberculosis in Zimbabwe. The Journal Of Infection In Developing Countries 11 (08): 611-618. https://doi.org/10.3855/jidc.8009
Section
Original Articles

Keywords

Tuberculosis; MDR-TB diagnosis; Sensitivity; Specificity; Turnaround time, Zimbabwe