Foreword Tereza Kasaeva We live in a world of global and local challenges: new threats, pandemics like COVID-19, climate change and natural disasters, armed conflicts and socioeconomic crises. These challenges affect many different regions and countries, and heavily impact on people’s life, health and wellbeing. However, the world today is also very dynamic, with many new opportunities and unprecedented advances in science and technology – and, of course, medicine. This is the backdrop that inspired world-renowned experts to come together as a team to develop this new issue of the ERS Monograph, The Challenge of Tuberculosis in the 21st Century. This Monograph is a consolidated, comprehensive guide to all key aspects of TB management and care, based on the latest data and WHO guidelines. It includes an overview of the progress made towards ending TB, and includes information on the latest evidence-based approaches to TB prevention, diagnosis and treatment. It also considers management of the TB response following the principles of people-centred care to address the specific needs of vulnerable groups and those with comorbidities. It places a spotlight on the importance for multisectoral engagement to address social determinants and drivers of the disease. In recent years, TB diagnosis has expanded considerably. Methods include: molecular tests for the detection of TB disease and drug resistance IGRAs and new antigen-based skin tests for the detection of TB infection computer-aided detection in TB screening using digital chest radiography. Clinical trials have evaluated: new drugs and regimens for TB treatment, including MDR-TB management of TB in children and adolescents and preventive treatment of TB infection. These advances have informed important updates of core WHO guidelines and have resulted in improved access to the latest diagnostic tests, treatment of both drug-susceptible TB and DR-TB, and development of TPT. It is now possible to achieve treatment with a shorter administration, that is fully oral and more effective. Copyright ©World Health Organization 2023. Print ISBN: 978-1-84984-169-6. Online ISBN: 978-1-84984-170-2. Print ISSN: 2312-508X. Online ISSN: 2312-5098. Tereza Kasaeva Director, WHO Global Tuberculosis Programme https://doi.org/10.1183/2312508X.10027722 vii