The Changing Landscape of Childhood Tuberculosis in the United Kingdom A Retrospective Cohort (2000-2015)

Background: The epidemiology of tuberculosis (TB) is changing in the United Kingdom and globally. Childhood TB is a key indicator of recent transmission and provides a marker of wider TB control. We describe the recent epidemiology of childhood TB in the United Kingdom, how this compares to TB in adults, and document changes with time. Methods: TB cases notified in the United Kingdom between 2000 and 2015 were categorized as children (< 15 years of age) or adults (>= 15 years of age). Descriptive analyses were carried out on demographic, clinical and microbiologic data. We carried out logistic regressions to identify risk factors associated with children having no microbiologic confirmation. Results: In the study period, 6293 TB cases (5%) in the United Kingdom were notified in children. Childhood TB incidence declined from 487 cases in 2000 (3.4 per 100,000) to 232 cases (2.0 per 100,000) in 2015. The majority (68%) of children with TB were UK born, with a high proportion of Pakistani (24%) and Black- African (22%) ethnicity. Sixty- four percent of children had pulmonary disease. Culture confirmation was low (24%). Children who were younger, UK born and those with extrapulmonary disease were less likely to have microbiologically confirmed TB. A high proportion (87%) of children completed treatment at last- recorded outcome, with few deaths (39 cases; 0.7%). Conclusions: The incidence of TB in children in the United Kingdom has decreased in the past 16 years, with the majority of children completing TB treatment. Ongoing monitoring of childhood TB will provide a measure of the effectiveness of the national TB program.