Science with Societal Implications: Detecting Mycobacterium tuberculosis in Africa

Mycobacterium tuberculosis is one of the world's leading infectious killers and a disease that disproportionately affects the global poor. Diagnosing tuberculosis (TB) with confidence remains an elusive task, especially in resource-limited settings, such as those throughout most of Africa. Most diagnostic protocols lack both speed and accuracy, as current methods rely on a combination of screening and confirmatory tests, including symptom-based questionnaires, direct smear and microscopy, mycobacterial culture, and chest radiograph. The Xpert MTB/RIF (Xpert) assay is a polymerase chain reaction (PCR)-based method for TB diagnosis. The assay presents an exciting prospect as a point-of-care (POC) or near-POC test; however, the assay cannot be implemented without changes in the budgets, staffing, and infrastructure of existing regional primary care clinics. This report provides a summary of the Xpert technology and both the benefits and challenges of its implementation as a POC test in resource-limited settings.