6 July 2021. Three new nucleic acid amplification test (NAAT) classes are endorsed by WHO and included. The latest operational handbook includes the new classes recommended by WHO. It aims at facilitating the implementation of the WHO recommendations by the Member States, technical partners, and others involved in managing patients with TB and DR-TB. The operational handbook provides practical information on existing and new tests recommended by WHO, step-by-step advice on implementing and scale-up testing to achieve local and national impact and lastly, model diagnostic algorithms, which are updated to incorporate the latest recommendations. An overview of budgetary considerations and information sheets on each of the newly recommended tests is provided.