Systematic screening for active tuberculosis: an operational guide

Publication Year 28 Aug 2023

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Executive summary

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.1,2 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.3 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.