WHO operational handbook on tuberculosis: module 3: diagnosis

This operational handbook provides practical guidance for implementing World Health Organization recommendations on the diagnosis of tuberculosis (TB), detection of drug-resistant TB and testing for TB infection. The publication consolidates, for the first time, operational guidance previously issued separately for TB diagnosis and TB infection testing, and aligns implementation advice with the 2025 WHO consolidated guidelines on tuberculosis: module 3: diagnosis. It describes the epidemiological and public health context of TB, outlines current WHO-recommended diagnostic technologies and algorithms, and summarizes recommendations for molecular, biomarker-based and immunological tests used in diverse clinical and laboratory settings.

The handbook addresses diagnostic strategies for pulmonary and extrapulmonary TB, drug susceptibility testing, testing for TB infection and concurrent testing approaches for populations at increased risk, including children and people living with HIV. It also provides guidance on laboratory network organization, quality assurance, regulatory and operational requirements, implementation planning, monitoring and evaluation, and the introduction of new diagnostic technologies, including targeted next-generation sequencing. Model diagnostic algorithms and practical implementation considerations are included to support national TB programmes, laboratories, clinicians and other stakeholders involved in TB prevention, detection and care.