OpiniãoThis operational handbook consolidates, for the first time, WHO’s consolidated guidelines on rapid diagnostics for TB detection (6) and tests for TB infection (13). Also, the contents have been revised to support the most recent, evidence-based WHO policy guidance that is described in the 2025 publication, WHO consolidated guidelines on tuberculosis: module 3: diagnosis (5). A high-level summary of the changes made between the third and fourth versions of this handbook is presented in Table 1.2.
Table 1.2. Summary of changes in this WHO operational handbook on tuberculosis. Module 3: diagnosis
Description of change
This fourth version of the operational handbook:
- for the first time, consolidates operational handbooks on tests for TB diagnosis and tests for TB infection into a single document, with harmonization of content;
- introduces a summary table listing all current WHO recommendations for the diagnosis of TB infection and disease, and the detection of drug resistance (Table 1.1);
- has additional tables to define each class of diagnostics (Section 2);
- includes two new classes of TB diagnostic tests used for the initial detection of TB, with and without detection of RIF resistance (low-complexity automated NAATs [LC-aNAATs] and low-complexity manual NAATs [LC-mNAATs]), summarizing content for within-class tests Xpert® MTB/RIF Ultra, Truenat® MTB Plus and Truenat MTB-RIF Dx (LC-aNAAT), and for TB-LAMP (LC-mNAAT) tests (Sections 2–4);
- includes new and updated testing products in the IGRA and targeted NGS classes of diagnostics (Section 2), based on a January 2025 WHO product assessment (the findings of which are summarized in meeting reports in Web Annex D);
- includes operational considerations for the new WHO recommendations on concurrent testing among people (of all ages) living with HIV, and among children without HIV or with unknown HIV status (Section 3, Algorithm 1);
- includes a new subsection on QA specific to TB testing (Section 3);
- provides revisions to the model diagnostic algorithms (Section 6):
- Algorithm 1 is now presented in two parts:
- the first part outlines sample collection and initial testing pathways for different populations, depending on their HIV status and age (reflecting new concurrent testing recommendations for people living with HIV and children, including the use of respiratory samples and stool on low complexity nucleic acid amplification tests and urine on the lateral flow urine lipoarabinomannan assay [LF-LAM]);
- the second part guides interpretation of test results pathways, including those for both molecular and biomarker-based tests;
- Algorithm 2 is specific to DST in settings with and without access to targeted NGS;
- Algorithm 3 addresses follow-on drug-resistance testing and interpretation for people with RIF-susceptible TB who are at risk of resistance to other anti-TB drugs; and
- Algorithm 4 addresses testing for TB infection and interpretation of results.
- Algorithm 1 is now presented in two parts:
- Content from the previous “Annex 5” has been moved into the References section of the main document.