DEDICATE (Blood-based diagnostic of paucibacillary TB in Bangladesh)

Context

According to the World Health Organization, in 2021 tuberculosis alternated between the first and the second cause of death due to infectious disease in the world, with around 1.6 million deaths, mainly recorded in countries with limited resources and increasing for the first time in ten years.

Conventional diagnostic tests for pulmonary tuberculosis currently used throughout the world rely on sputum analysis. The sensitivity of these tests is greatly reduced in the diagnosis of paucibacillary forms of TB, such as paediatric or extra-pulmonary tuberculosis, leading to the significant under-diagnosis of these two forms of the disease.  A triage test for TB using a sample that is not sputum based is one of the WHO’s main priorities.

To date, molecular blood tests including RISK6 or the Cepheid® Xpert-MTB-HR prototype, both based on the detection of a transcriptomic signature in the host, represent a promising and innovative alternative for the diagnosis of paucibacillary forms of tuberculosis.

In 2021, the HINTT research consortium, coordinated by the Mérieux Foundation as part of the GABRIEL network, demonstrated that the RISK6 blood test had excellent performance in terms of sensitivity and specificity for screening and monitoring the treatment of pulmonary tuberculosis in adults.

Objectives

Based on these results, the Mérieux Foundation and its partners have set up the DEDICATE project in Bangladesh, which aims to evaluate the performance of the two blood tests RISK6 and Xpert-MTB-HR for the triage and diagnosis of paediatric and extra-pulmonary tuberculosis. The second phase of this study also aims to evaluate these tests as a tool for monitoring the therapeutic treatment of tuberculosis.

This study is part of the WHO’s plan to combat tuberculosis, and more specifically to reduce the morbidity and mortality of this disease in countries with limited resources.

Activities

This 18-month prospective study is an observational study in a hospital environment focussing on two cohorts:

• Children (under 15 years of age) with suspected pulmonary TB.
• Children (over 11 years of age), adolescents and adults with suspected extra-pulmonary tuberculosis (EPTB) referred to the Tuberculosis Screening and Treatment Centre at icddr,b in Bangladesh by private physicians.

In both cohorts, patients diagnosed with TB will be monitored during their treatment (up to 9 months for resistant TB) and the relevance of these tests as a triage/diagnostic or therapeutic prognostic tool will be evaluated.