New diagnostics for tuberculosis: fulfilling patient needs first

An effective tuberculosis (TB) control programme requires early diagnosis and immediate initiation of treatment. Any delays in diagnosing TB not only impair a patient's prognosis, but also increase the risks of transmitting the disease within the community. Unfortunately, the most recent TB diagnostic tools still depend on high-infrastructure laboratories, making them poorly adapted for use in resource-limited settings. Additionally, existing tests show poor performance in diagnosing TB in children, people living with HIV/AIDS, and extrapulmonary forms of the disease. As a consequence, TB patients are still to date left with either fair access to poor diagnostics or poor access to fair diagnostics.

This article discusses recent efforts to identify the minimal test specifications for a new TB point-of-care diagnostic test through an approach based on medical and patient needs. As a first step, survey interviews with field practitioners were designed in order to identify the top-priority medical needs in resource-limited settings concerning new TB diagnostics. Subsequently, an expert meeting convening field practitioners, laboratory experts, diagnostic test developers and researchers was held with the objective of defining the minimal test specifications for a new TB point-of-care test that would meet the identified medical needs. Finally, gaps in, as well as potential solutions for, enabling the development of adequate, patient needs-driven, low-cost new TB diagnostic tests specifically designed for vulnerable populations are discussed.

Any new TB point-of-care diagnostic test should be designed to meet minimal specifications satisfying the most urgent medical needs in resource-poor settings. The major gaps for developing a new TB point-of-care test include identification of new biomarkers, simplification of technological platforms, development of adequate and accessible specimen banks, and identification and definition of reference standards for diagnosis of childhood TB. Innovative research and development funding ensuring de-linkage of research and development costs from the price of the new product, such as a prize fund mechanism, could help focus these efforts towards the delivery of a much-needed point-of-care diagnostic test for TB.