Newly available tests for rapid TB diagnosis: what you need to know
15 May 2020, Geneva, Switzerland – Three products have recently been made available to support TB programmes’ efforts to reach UN TB targets to detect and treat 40 million people with TB by 2022, including 3.5 million children, as well as 1.5 million people with drug-resistant TB. All three tests offer opportunities for multiplexing, with menus of tests for other diseases available, including COVID-19 tests.
Coverage and access to rapid TB diagnosis and drug susceptibility testing need to be quickly scaled up globally. Only 22% of the estimated number of people with TB were identified using a rapid diagnostic in 2018 according to World Health Organization (WHO) data, a long way to go to reach the End TB target of 100% no later than 2025. Only about half of people detected with TB had access to testing for rifampicin resistance; access to testing for resistance to other drugs is even direr. Therefore, it is essential that country programmes ensure a ramp-up of efforts for TB diagnosis and to be aware of these newly available tools.
- In January 2020, WHO issued a Rapid Communication in advance of upcoming policy guidance that will describe recommendations on the use of the Truenat tests for the detection of TB and rifampicin resistance. Truenat is a rapid, chip-based real-time PCR testing technology that can be positioned at point-of-care settings using equipment with in-built batteries. The manufacturer of Truenat is Molbio Diagnostics Pvt. Ltd. (Goa, India). The Stop TB Partnership and USAID have published Practical Considerations for Implementation of Truenat, for countries wishing to learn more about this technology.
- In March 2020, the Global Fund’s Expert Review Panel for Diagnostics (ERPD) approved two real-time PCR tests for the rapid detection of TB and resistance to rifampicin and isoniazid using high-throughput instruments: the Abbott RealTime MTB and MTB RIF/INH tests (Abbott Laboratories, USA), and the BD MAX MDR-TB test (Becton, Dickinson and Company, USA). ERPD approval of TB diagnostics is intended as an interim approval mechanism on the pathway to potential WHO endorsement and allows countries to use Global Fund funding to procure products. For more details on these tests, see the Stop TB Partnership Information Note on Implementation of ERPD-approved Molecular Tests for Detection of TB and Resistance to Rifampicin and Isoniazid.
- In addition to these three new technologies, the WHO Rapid Communication also indicates that evidence supports the use of Xpert MTB/RIF and Xpert Ultra for testing stool specimens of children. Given difficulties in collecting samples from children, including traumatizing methods required to obtain nasopharyngeal and gastric specimens, testing of stool would offer an easy solution.
Source: Stop TB Partnership
