"More than one third of the 9 million people who fall ill with tuberculosis (TB) each year are not diagnosed, not notified, or do not start treatment. Many of those who do start treatment have a delayed start due to a range of challenges. Such obstacles to receive care can result in poor health outcomes for the affected individuals, catastrophic costs for their families and continued transmission of TB to others in their communities. In addition, the individuals and communities at highest risk of falling ill with TB are often those with the least access to health care and treatment for the disease, further compounding the negative effects of the disease. These barriers to care, coupled with the magnitude and persistence of the global TB burden, argue for a redoubling of efforts to ensure early identification of and treatment for all people with TB. To this end, the systematic screening of those at high risk for TB is a key component of the World Health Organization's (WHO) End TB strategy, 2016 to 2035. Like all case-finding strategies, systematic screening for TB has three primary goals: 1. to ensure the early detection and initiation of appropriate treatment for those with active TB; 2. to reduce the risk of poor treatment outcomes, health sequelae and the adverse social and economic consequences of TB; and 3. to reduce transmission of TB, with the ultimate goal of reducing future incidence. The WHO has published guidelines that set out the principles for screening for active TB and provide recommendations on prioritizing of risk groups and choosing a screening approach.6 Screening should not be done on a mass, indiscriminate scale because this is expensive, of relatively low benefit and can result in many false positive results. One of the key principles set out in the guidelines is that screening for TB needs to be properly targeted to high-risk groups and tailored to each specific situation, depending on the epidemiological, social and health-systems contexts. This document provides practical guidance on translating WHO's principles and recommendations into a national or local screening strategy by: 1. assessing the situation; 2. defining the objectives of screening; 3. prioritizing risk groups for screening; 4. choosing screening tools, algorithms and approaches for each risk group; 5. planning and budgeting for, and implementing the strategy; 6. monitoring and evaluating the strategy. The guide includes a description of a web-based tool that can be used to help identify and prioritize risk groups and chose appropriate screening and diagnostic algorithms. The tool is designed to assist with the initial planning stages of creating a targeted screening strategy, but several other factors than those covered by the tool need to be considered in the planning process. This guide also includes additional online material, including other tools and references to assist with planning and implementing screening programmes."--Page 4

The WHO consolidated guidelines on tuberculosis. Module 2: screening – systematic screening for tuberculosis disease is an updated and consolidated summary of WHO recommendations on systematic screening for tuberculosis (TB) disease, containing 17 recommendations for populations in which TB screening should be conducted and tools to be used for TB screening. TB screening is strongly recommendations for household and close contacts of individuals with TB, people living with HIV, miners exposed to silica dust, and prisoners. In addition, screening is conditionally recommended for people with risk factors for TB attending health care, and for communities with risk factors for TB and limited access to care (e.g. homeless, urban poor, refugees, migrants). General population screening is recommended in high-burden settings (0.5% prevalence or higher). Symptoms, chest radiography (CXR), and molecular WHO-recommended rapid diagnostic tests for TB are recommended as screening tools for all adults eligible for screening. Computer-aided detection programmes are recommended as alternatives to human interpretation of CXR in settings where trained personnel are scarce. For people living with HIV, C-reactive protein is also a good screening tool. This guideline document is accompanied by an operational handbook, the WHO operational handbook on tuberculosis. Module 2: screening – systematic screening for tuberculosis disease, that presents principles of screening, steps in planning and implementing a screening programme, and algorithm options for screening different populations.

This handbook is the companion implementation guide to the 2021 WHO consolidated guidelines on tuberculosis: Module 2: Screening. Systematic screening for tuberculosis disease. This handbook is part of a modular series of practical guides meant for the implementers of various aspects of the programmatic management TB. The operational handbook discusses six essential steps in designing and implementing a TB screening programme: assessing the situation, setting goals and specific objectives, identifying and prioritizing risk groups, choosing algorithms for screening and diagnosis, planning, budgeting and implementing, and monitoring, evaluating and modifying the programme. The handbook also contains various algorithm options for screening in different populations including: 10 possible screening algorithms for the general population and high-risk groups, 11 algorithms for adults and adolescents ≥10 years living with HIV, and 6 algorithms for children (5 for child contacts an 1 for children 10 years living with HIV). brIn addition, WHO links to 2 web-based tools to assist with planning and implementation of screening activities: 1) iScreenTBCAD for TB detection which helps countries with calibrating CAD technologies for new settings.

There have been calls to revisit the experiences of TB screening campaigns that were widely applied in Europe and North America in the mid-20th century, as well as more recent experiences with TB screening in countries with a high burden of the disease, and to assess their possible relevance for TB care and prevention in the 21st century. In response, WHO has developed guidelines on screening for active TB. An extensive review of the evidence has been undertaken. The review suggests that screening, if done in the right way and targeting the right people, may reduce suffering and death, but the review also highlights several reasons to be cautious. As discussed in detail in this book, there is a need to balance potential benefits against the risks and costs of screening; this conclusion is mirrored by the history of TB screening. This publication presents the first comprehensive assessment by WHO of the appropriateness of screening for active TB since the recommendations made in 1974 by the Expert Committee. However, the relative effectiveness and cost effectiveness of screening remain uncertain, a point that is underscored by the systematic reviews presented in this guideline. Evidence suggests that some risk groups should always be screened, whereas the prioritization of other risk groups as well as the choice of screening approach depend on the epidemiology, the health-system context, and the resources available. This book sets out basic principles for prioritizing risk groups and choosing a screening approach; it also emphasizes the importance of assessing the epidemiological situation, adapting approaches to local situations, integrating TB screening into other health-promotion activities, minimizing the risk of harm to individuals, and engaging in continual monitoring and evaluation. It calls for more and better research to assess the impact of screening and to develop and evaluate new screening tests and approaches.

This Rapid Communication is being issued to help national TB programmes and other stakeholders prepare for the changes that will be introduced with the new guidelines on TB screening.

The political declaration of the first United Nations (UN) high-level meeting on tuberculosis (TB) calls countries to diagnose and treat 40 million people with TB globally between 2018 and 2022. Traditionally, in most countries, TB diagnosis has been performed using sputum-smear microscopy, a method developed more than 100 years ago, with suboptimal sensitivity. In recent years new technologies have emerged based on the detection of mycobacterial DNA or mycobacterial antigens. Over the past decade the World Health Organization (WHO) has published a number of guidelines developed by WHO-convened Guideline Development Groups (GDGs), using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to summarize the evidence and to formulate policy recommendations and accompanying remarks. The present document "WHO consolidated guidelines on tuberculosis. Module 3: Diagnosis - Rapid diagnostics for tuberculosis detection" consolidates five guidelines developed by WHO between 2016 and 2020. Earlier guidelines on diagnostics that were not developed according to the GRADE approach have not been included in this document. The WHO Consolidated Guidelines on Tuberculosis will group all TB recommendations in one document and will be complemented by matching modules of an operational handbook. The handbook will provide practical advice on how to put in place the recommendations at the scale needed to achieve national and global impact. A range of new diagnostic technologies have been endorsed by WHO during the past decade. These are listed below: - real-time polymerase chain reaction (PCR) assays - for example, Xpert MTB/RIF(r) (Ultra) (cartridge-based) and TruenatTM (chip-based);- line probe assays (LPAs) - for example, GenoType(r) MTBDRplus v1 and v2, GenoscholarTM NTM+MDRTB II and GenoType(r) MTBDRsl;- loop-mediated isothermal amplification (LAMP) - for example, TB-LAMP; and- antigen detection in a lateral flow format (biomarker-based detection) - for example, Alere DetermineTM TB LAM Ag. The present "WHO consolidated guidelines on tuberculosis. Module 3: Diagnosis - Rapid diagnostics for tuberculosis detection" provides background, justification and recommendations on these technologies. The document includes new recommendations on molecular assays intended as initial tests for the diagnosis of pulmonary and extrapulmonary TB and rifampicin resistance in adults and children.