TB diagnostics and laboratory strengthening
Lack of diagnostic capacity has been a crucial barrier preventing an effective response to the challenges of HIV-associated and drug resistant tuberculosis (TB), with only 7% of the estimated global burden of multi-drug resistant tuberculosis (MDR-TB) and an even smaller fraction of XDR-TB cases being detected, the consequence of critical gaps in laboratory capacity for culture and drug susceptibility testing (DST). Therefore, the expanded capacity to diagnose TB and MDR-TB is a global priority for TB control.
Care of patients with tuberculosis starts with a quality assured diagnosis, obtained by growing and identifying Mycobacterium tuberculosis from clinical specimens and conducting DST of the organism to confirm or exclude resistance. Research on new TB diagnostic tools has been accelerated over the last few years and the diagnostic pipeline has been growing rapidly as a result. At the same time, an unprecedented effort to improve and expand TB laboratory capacity is currently being lead by WHO and the Stop TB Partnership Global Laboratory Initiative (GLI) together with the GLI network of international collaborators (http://www.stoptb.org/wg/gli).
Uptake of TB diagnostic technologies requires appropriate laboratory infrastructure and adequate policy reform at country level to enable their effective use in TB screening and diagnostic algorithms. WHO has established a structured, systematic process to rapidly review the evidence base for new TB diagnostics, ensuring that new tools meet the required performance standards. Nevertheless, even the best tools are bound to fail if all core elements of laboratory services are not addressed at the same time. These include:
- Laboratory infrastructure, appropriate biosafety measures and maintenance
- Equipment validation and maintenance
- Specimen transport and referral mechanisms
- Management of laboratory commodities and supplies
- Laboratory information and data management systems
- Laboratory quality management systems
- Appropriate, adequate strategies and funding for laboratory human resource development
- Coordination of technical assistance
- Integration of diagnostic algorithms in laboratory strengthening plans.
- Laboratory tool set (including GLI roadmap for strengthening TB laboratory services within the context of national strategic plans for laboratory services)
Framework for implementing new tuberculosis diagnostics, 2010
The point-of-care diagnostic tests for TB are not expected before 2015; therefore, uptake of existing WHO-recommended technologies must be accelerated, which requires adequate laboratory infrastructure and clear policies at country level on their use in TB screening and diagnostic algorithms. Because of the complexity of laboratory strengthening, the involvement of an expert laboratory consultant is recommended to guide the implementation process at country level.