NEW YORK ─ The World Health Organization on Thursday issued an update to its consolidated guidelines on the detection of tuberculosis and drug-resistant tuberculosis, recommending rapid molecular assays as the initial test to diagnose TB instead of sputum smear microscopy.
The guidelines are accompanied by an operational handbook to facilitate rapid implementation and rollout of rapid molecular tests by national TB programs, ministries of health, and technical partners, the WHO said.
Use of rapid molecular assays will lead to major improvements in the early detection of TB and drug-resistant TB, the WHO said, and the organization included three new classes of technologies in its updated guidelines. The first class is moderate-complexity, automated nucleic acid amplification tests, or NAATs, recommended for the initial detection of TB and resistance to rifampicin and isoniazid. These NAATs provide more options for early diagnosis of TB and rifampicin-resistant TB, and address an important gap in the rapid diagnosis of isoniazid-resistant and rifampicin-susceptible TB, the WHO said.
The second class of technologies is low-complexity, automated NAATs recommended for the detection of resistance to isoniazid and second-line anti-TB agents. They will improve access to testing of fluoroquinolones resistant at peripheral level, according to the WHO.
The third class is high-complexity, reverse hybridization-based NAATs recommended for the detection of pyrazinamide resistance. They represent the first molecular tests for resistance determination to the drug, the WHO said.
"We call for rapid action and stakeholder support in ensuring these updates are rapidly implemented to enable access to the latest technologies and innovations," Tereza Kasaeva, director of the WHO global TB program, said in a statement.
In February, the WHO announced that it has found high diagnostic accuracy for three classes of molecular diagnostic technologies for tuberculosis testing in advance of the update to its guidelines for TB diagnostic tests.
In March, the organization released updated recommendations for the use of point-of-care tests in children less than 18 months and the monitoring of treatment in people living with HIV.