Skip to main content

Table 3 Expected costs of diagnostic algorithms

From: Comparison of laboratory costs of rapid molecular tests and conventional diagnostics for detection of tuberculosis and drug-resistant tuberculosis in South Africa

Algorithm

Cost per sample

Incremental cost

Implementation of conventional diagnostics versus molecular testing

  

Fluorescence microscopy plus liquid culture testing scenario* on all sputa

$16.88

reference

Xpert MTB/RIF alone on all sputa

$14.93

$-1.95

MTBDRplus alone on all sputa

$23.46

$6.58

Intensive implementation of molecular tests in combination with conventional diagnostics

  

Xpert MTB/RIF plus liquid culture testing scenario* on all sputa

$28.41

$11.53

MTBDRplus plus liquid culture testing scenario* on all sputa

$36.94

$20.06

Conventional diagnostics with selective implementation of molecular tests

  

Fluorescence microscopy plus liquid culture testing scenario* on all sputa + Xpert MTB/RIF on smear-positive sputa

$18.37

$1.49

Fluorescence microscopy plus liquid culture testing scenario* on all sputa + MTBDRplus on smear-positive sputa

$19.23

$2.35

Fluorescence microscopy on all sputa plus a) Xpert MTB/RIF on smear-positive sputa and b) liquid culture on smear-negative sputa with Xpert MTB/RIF on culture positive isolates

$16.51

-$0.37

Fluorescence microscopy on all sputa plus a) MTBDRplus on smear-positive sputa and b) liquid culture on smear-negative sputa with MTBDRplus on culture positive isolates

$17.75

$0.87

Molecular testing with selective implementation of culture and dst**

  

Xpert MTB/RIF on all sputa, with liquid culture testing scenario* on sputa with a positive molecular test

$16.86

$-0.02

MTBDRplus on all sputa, with liquid culture testing scenario* on sputa with a positive molecular test

$25.39

$8.51

  1. Abbreviations: MGIT Mycobacterial Growth Indicator 960 automated liquid culture system, DST Drug Susceptibility Testing using MGIT SIRE system.
  2. * Liquid culture testing scenario consists of sputum processing and MGIT culture, followed by Ziehl Neelsen smear microscopy on positive cultures, anti-MPB64 assays on cultures with mycobacterial growth, and MGIT SIRE DST on cultures with growth of M. tuberculosis.
  3. **Utilizes current estimates of Xpert and MTBDRplus sensitivity and specificity and prevalence of TB and drug-resistant TB in South Africa.
Back to article page

BMC Infectious Diseases

ISSN: 1471-2334

Contact us