New diagnostic tools for tuberculosis.

Rapid and accurate diagnosis of symptomatic patients is a cornerstone of global tuberculosis control strategies. Remarkable progress has recently been made, upgrading the speed and quality of mycobacteriology diagnostic services in industrialized countries, but for most of the world where TB is a large public health burden those gains are still unrealized. Deficiencies in current case-finding tools in disease endemic countries have made it difficult to ensure access to good diagnostics at all health service levels, leaving many patients undiagnosed. Additionally, in well-established TB control programs where diagnostic access has been ensured, efforts to interrupt disease transmission have been hampered by the insensitivity and late detection of smear microscopy. Fortunately, technical progress in diagnostics is resulting in a number of improved tools, including some appropriate for low-income settings. Important work remains, however, before new diagnostic tools can be meaningfully integrated into national TB control programs of high-burden countries and before TB control strategies can take them into account. The design and quality of clinical trials evaluating new diagnostics must be improved, clinical and laboratory services that would allow rapid response to test results need to be enhanced, and basic and operational research to appraise the impact and cost-effectiveness of new diagnostic technologies must be carried out. This paper describes some of the recent advances in TB diagnostic technologies and puts them into perspective for global tuberculosis control.