 Introduction, adolescents are particularly vulnerable to contracting tuberculosis, TB, as well as developing more severe forms of the disease than younger children. Reasons for increased susceptibility to TB infection and higher incidence of TB disease in adolescents, compared with the 5-10 years old age group, are incompletely understood. Despite the pressing clinical and public health need to better understand and address adolescent TB, research in this field remains limited. Methods and analysis, teen TB is an ongoing prospective observational cohort study that aims to better understand the biology, morbidity and social context of adolescent TB. The study plans to recruit 50 adolescents, 10-19 years old, with newly diagnosed microbiologically confirmed pulmonary TB disease and 50 TB exposed controls without evidence of TB disease in Cape Town, South Africa, which is highly endemic for TB. At baseline, cases and controls will undergo a detailed clinical evaluation, chest imaging, respiratory function assessments and blood collection for viral. This article was authored by Aniksi Hesseling, Alex Deruta, Elizabeth Whittaker and others. We are article.tv, links in the description below.