Tuberculosis (TB) is a leading cause of morbidity and mortality in Zambia, especially amongHIV-infected persons. The lack of adequate diagnostic tools is a key challenge to TB control inthe public health system. The Xpert MTB/RIF platform has the potential to transform TBdiagnostics by providing accurate same-day results, but studies are required to evaluate thefeasibility and cost-effectiveness of this technology before it can be scaled-up. We propose anevaluation of Xpert MTB/RIF using a quasi-experimental 'before-after' study design in pediatricand adult HIV-infected populations in two similar peri-urban district hospitals in Zambia. Wewill compare the standard algorithmic approach to TB diagnosis endorsed by the ZambianMinistry of Health to an enhanced algorithm that incorporates Xpert MTB/RIF. The primaryoutcomes will be the proportions of adult and pediatric patients receiving appropriate TBtreatment in each study phase, using mycobacterial culture as the reference standard, and thefeasibility and cost effectiveness of Xpert MTB/RIF in this setting. Secondary outcomes includea comparison of the time to diagnosis and treatment initiation in TB-infected patients, acomparison of clinical outcomes at three and six months post TB screening between the twostudy phases, and an evaluation of the diagnostic performance of Xpert MTB/RIF using sputumand gastric aspirate specimens in the pediatric population. This study will enable the Ministry ofHealth to make informed decisions regarding future implementation of Xpert MTB/RIF andintensified case finding in Zambia.2
The Xpert MTB/RIF platform has the potential to address many challenges to TB diagnosis and treatment by providing accurate, same-day test results, but it is expensive and potentially unfeasible for use in low resource settings. Field testing will determine whether implementation of Xpert MTB/RIF is feasible and cost-effective, and whether it will have a significant impact on clinical outcomes. Furthermore, evaluation of the diagnostic performance of Xpert MTB/RIF in children will provide key information about the utility of Xpert MTB/RIF in diagnosing pediatric TB in resource-poor settings. 3
