Point-of-care molecular TB test

What is this project?

We are evaluating the performance and accuracy of point-of-care (POC) molecular diagnostic tests developed by Bangalore-based company Molbio Diagnostics, using a machine known as Truenat^TM. Truenat assays use nucleic acid amplification test (NAAT) technology to identify TB, as well as to detect resistance to rifampicin, the most commonly used anti-TB drug.

Why are we working on it?

While India is one of the highest-burden TB countries in the world, this is the first time that a TB test has been developed by an Indian company. Cartridge-based (CB-)NAAT is widely used in the country, and has transformed TB diagnosis by reducing the time-to-result from months to hours, allowing patients to start treatment without delay.

Truenat machines are designed to be used close to the POC, as they are battery operated and do not need to be housed in air-conditioned facilities. They are therefore particularly well-suited for use in low-resource primary healthcare settings.

What does it involve?

Following successful pilot study completion, we are now assessing the performance and accuracy of the Truenat MTB assay (to identify TB) and MTB-Rif assay (to also identify resistance to rifampicin), in multicentre clinical trials in real-world settings in India, Peru, Ethiopia and Papua New Guinea.

We expect enrolment of over 1,600 patients in total, including those who are HIV positive. TB is the most common cause of death in people with HIV, but HIV can complicate TB identification and therefore make TB diagnosis particularly difficult.

What do we expect to achieve?

Results from this trial will determine the diagnostic accuracy of the Truenat MTB and MTB-Rif assays, using culture and phenotypic/genotypic drug susceptibility tests in settings of intended use. Diagnostic accuracy will also be benchmarked versus existing CB-NAAT diagnostics.

Together with supporting laboratory and clinical data, this clinical evaluation will enable a WHO assessment of the Truenat MTB and MTB-Rif assays, and inform subsequent development of potential policy recommendations and national guidance documentation.

Partners and funding

The Truenat MTB and MTB-Rif assays were developed by Molbio Diagnostics in partnership with FIND. The clinical evaluation studies are being conducted in partnership with the National Institute for Research in Tuberculosis (India), the P.D. Hinduja Hospital (India), Universidad Peruana Cayetano Heredia (Peru), the Ethiopian Public Health Institute (Ethiopia), and the Port Moresby General Hospital (Papua New Guinea), with support from the Burnet Institute (Australia).

This work is supported by funders including the Bill & Melinda Gates Foundation, the Indian Council for Medical Research (ICMR) and the India TB Research Consortium (ITRC), as well as UK aid from the British people.