GeneXpert for TB diagnosis: planned and purposeful implementation

Abstract

Xpert MTB/RIF is a major advance for TB diagnostics, especially for multidrug-resistant (MDR) TB and HIV-associated TB. But implementation concerns including cost, technical support requirements, and challenging demands of providing second-line TB drugs for diagnosed MDR-TB cases call for gradual, careful introduction based on country circumstances.

Rapid Detection of Mycobacterium tuberculosis in Sputum Samples by Cepheid Xpert Assay: A Clinical Study

“…However, cost of Xpert assay is more than smear microscopy; it requires a machine that currently costs US$17,000 and cartridges that cost US$9.98 for each test, in addition to human resource and other running costs [20]. Vassall et al, reported the cost for the Xpert test (including all costs, such as the cartridge, equipment, salaries) ranges from US$22.63 in India to US$27.55 in Uganda [21].…”

Unsuccessful Xpert® MTB/RIF results: the Nigerian experience

“…7 However, the right placement of Xpert machines in the laboratory requires careful consideration of available resources, national capacity building and accessibility of diagnostic testing. 8 …”

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

“…However, it is expensive and requires moderate levels of infrastructure (such as an airconditioned room and reliable power supplies). That may not be suitable for primary care centres [19]. The main limitation of GeneXprt MTB/RIF is that it cannot be reliably used to detect resistance to first-line [13,23,24].…”

“…Including automatic reading of tubes into the MGIT assay adds considerably to the costs and has advantage only in settings where there is a high flow of specimens through the laboratory. All of these assays, however, require safe facilities and highly skilled personnel, suggesting they are best placed at tertiary levels of care [1,19]. Solid LJ-DST is still regarded as the standard by which to compare the reliability of other tests [25].…”

“…Scores were ranked based on Zeman DH principle and the total ranking scores were used to assess overall performance [18,19] [15][16][17][18][19][20]. Cost estimates were generated through consideration of all substantial resource inputs necessary to perform each diagnostic test, including laboratory overhead costs, personnel costs, laboratory equipment, consumable supplies, test reagents, sample collection, transportation, and sample decontamination.…”