Recent advances in tuberculosis diagnostics in resource-limited settings.

ABSTRACT

Smear-negative and drug-resistant cases of tuberculosis (TB) disease necessitate the development of new diagnostic methods, especially in resource-limited settings. To improve the current TB situations, sensitive and specific TB point-of-care tests (POCTs) should be developed. This review addresses the current status of TB, novel diagnostic methodologies for TB, and the impact of those new diagnostics on TB control in such situations. Moreover, the perspective of TB management based on laboratory examinations is described. Smear microscopy with sputum samples is the only laboratory examination available in many resource-limited settings and is still used globally. Several nucleic acid amplification tests (NATs) have been developed. The World Health Organization (WHO) endorsed novel diagnostics based on NATs and updated their definition of a bacteriologically confirmed case requiring the biological specimen to be positive by smear microscopy, culture, or the WHO-recommended rapid diagnostic protocols. The use of new diagnostics increased the number of bacteriologically confirmed TB cases. Novel diagnostics are now available, but their sensitivity is still lower than that of conventional liquid culture method. To address the increasing incidence of TB, more resources including novel diagnostics as POCTs with higher sensitivity must be allocated to healthcare systems.