Original from: 360dx

The World Health Organization has published updated guidelines for the rapid diagnosis of tuberculosis, including new recommendations on the use of targeted next-generation sequencing (NGS) tests for drug-resistant TB.

Specifically, the guidelines note that in people with bacteriologically confirmed pulmonary TB disease, targeted NGS may be used on respiratory samples to diagnose resistance to rifampicin, isoniazid, fluoroquinolones, pyrazinamide, and ethambutol, rather than culture-based phenotypic drug susceptibility testing.

The guidelines also state that in people with bacteriologically confirmed rifampicin-resistant pulmonary TB disease, targeted NGS technologies may be used on respiratory samples to diagnose resistance to the other aforementioned drugs.

The WHO specifically highlighted three NGS tests: Deeplex Myc-TB from Genoscreen in France; AmPORE-TB from Oxford Nanopore Diagnostics in the UK; and Tbseq from Hangzhou ShengTing Medical Technology in China. Each of these assays is able to diagnose resistance to different groups of drugs, the WHO noted, stating that where a product hasn't yet met the requirements for a specific drug, further improvements are needed and a review of evidence is necessary before clinical use.

The newly published guidelines also highlight various other molecular technologies for rapid TB diagnosis and resistance detection, including moderate-complexity automated nucleic acid amplification technologies (NAATs) for the detection of TB and resistance to rifampicin and isoniazid; lateral flow antigen detection tests; low-complexity automated NAATs for the detection of resistance to isoniazid and second-line anti-TB agents; and line-probe assays.

The guidelines are accompanied by a WHO operational handbook, which provides detailed guidance on implementing the targeted NGS tests for laboratory personnel and clinicians as well as other stakeholders. It describes the recommended targeted NGS tests, including their protocols, model algorithms, and the steps required to implement and scale up these tests.

The WHO also said it has launched a new TB sequencing portal with more than 56,000 sequences. Developed in partnership with FIND and Unitaid, the portal contains the most advanced sequencing and phenotyping knowledgebase for Mycobacterium tuberculosis, according to the organization.

The portal also includes a dashboard to help users visualize the data used in the WHO mutation catalog that was published in November 2023 and search for mutation frequencies and their association with drug resistance, as well as download summary data and upload new data.

"The diagnostic options for people with drug-resistant TB are increasing thanks to manufacturer engagement and research, generating new evidence," Tereza Kasaeva, director of WHO's Global TB Programme, said in a statement. "Ensuring that everyone in need can obtain a rapid and accurate diagnosis with the latest state-of-the-art technologies will advance efforts at preventing and finally ending TB."

Source: WHO Publishes New Guidance Recommending Targeted NGS for Drug-Resistant TB Diagnosis