Detecting tuberculosis: rapid tools but slow progress

Abstract

The World Health Organization (WHO) currently recommends Xpert® MTB/RIF as the initial test for all people with presumptive tuberculosis (TB). A number of challenges have been reported, however, in using this technology, particularly in low-resource settings. Here we examine these challenges, and provide our perspective of the barriers to Xpert scale-up as assessed through a survey in 16 TB burden countries in which the Médecins Sans Frontières is present. We observed that the key barriers to scale-up include a lack of policy adoption and implementation of WHO recommendations for the use of Xpert, resulting from high costs, poor sensitisation of clinical staff and a high turnover of trained laboratory staff; insufficient service and maintenance provision provided by the manufacturer; and inadequate resources for sustainability and expansion. Funding is a critical issue as countries begin to transition out of support from the Global Fund. While it is clear that there is still an urgent need for research into and development of a rapid, affordable point-of-care test for TB that is truly adapted for use in low-resource settings, countries in the meantime need to develop functional and sustainable Xpert networks in order to close the existing diagnostic gap.

Does Mycobacterium tuberculosis var. bovis Survival in the Environment Confound Bovine Tuberculosis Control and Eradication? A Literature Review

“…Similarly, the World Health Organisation (WHO) has recently endorsed the semiautomated PCR test GeneXpert® MTB/RIF (Cepheid Corp.) as the frontline test for presumptive human TB in a range of clinical samples, most notably sputum [ 128 ]. It is telling, however, that while there has been an understandable drive to develop rapid diagnostics with better performance characteristics, progress and validation have been disappointing—“ rapid tools but slow progress ” [ 128 ]. Two problems loom large on the TB direct detection horizon.…”

HIV-associated tuberculosis

“…Challenges in the scale of Xpert include lack of knowledge among clinical staff, insufficient support for maintenance, and a high price (at least US$9.98 per cartridge). 68 LF-LAM has emerged as an additional point-of-care test for TB in people living with HIV. 69,70 LF-LAM is recommended to assist diagnosis of TB in people living with HIV who have signs and symptoms of TB or a low CD4 count (<200 cells/mm 3 for inpatients and <100 for outpatients); and those who are seriously ill. 71 The sensitivity of LF-LAM is highest when CD4 count is low, but it is still around 50% with 84%-98% specificity.…”

Implementation of Xpert® MTB/RIF in high-burden countries: voices from the field matter

“…In this context, the survey of stakeholders by England et al from 16 high-burden countries provides valuable data and insights. 5 While previous studies have discussed concerns around cost 6 and the slow pace of policy change in countries, 1 England et al provide interesting data on barriers created by the poor sensitisation of clinical staff, and a high turnover of trained laboratory staff.…”

“…Yet another key finding is challenges faced by countries for service and maintenance provision; only half the countries surveyed stated that they were fully satisfied with the services provided. 5 Turnaround times for module replacement ranged from 7 days to 1 year, with about 40% of countries having modules replaced in less than 1 month. 5 Finally, England et al describe the over-reliance on the Global Fund for Xpert implementation.…”