The global burden of tuberculosis mortality in children: a mathematical modelling study

Background: Tuberculosis (TB) in children is increasingly recognised as an important component of the global TB burden, with an estimated 1 million cases in 2015. Although younger children are vulnerable to severe forms of TB disease, no age-disaggregated estimates of paediatric TB mortality exist, and TB has never appeared in official estimates of under-five child mortality.

Methods: We estimated deaths in children aged <5 and 5 to <15 for 217 countries and territories using a case-fatality-based approach. We used paediatric TB notifications data, HIV and antiretroviral treatment estimates to disaggregate the World Health Organization (WHO) paediatric TB incidence estimates by age, HIV and treatment status. Systematic review evidence on corresponding case fatality ratios was then applied.

Findings: We estimated that 239,000 (95% uncertainty interval [UI] 194,000 - 298,000) children aged <15 died due to TB globally in 2015; around 80% of these deaths - 191,000 (95%UI: 132,000 - 257,000) - were in children <5 years old. Over 70% of deaths occurred in the WHO South-East Asia and Africa regions. We estimated around 20% of paediatric TB deaths globally were in children with HIV infections, with this proportion nearer 30% in the WHO Africa region. Over 96% of all TB deaths occurred in children not receiving TB treatment.

Interpretation: Tuberculosis is a top ten cause of death in children and a key omission from previous analyses of under-5 mortality. Almost all these deaths occur in children not on tuberculosis treatment, implying substantial scope to reduce this burden.

Funding: UNITAID, NIH, NIHR