Potential Impact: The benefits of an accurate, rapid diagnostic test of TB infection in children include 1) timely institution of treatment for TB infection to prevent severe disease and mortality, and 2) preclusion of over diagnosis and treatment. Treatment of childhood TB infection also prevents future contagious adult disease, thus decreasing community transmission. Blood-based diagnostic testing may also be able to identify children that are more likely to become ill following TB infection. Therefore, blood-based diagnostic testing has great potential to improve TB control and the health of HIV-infected and uninfected children, their households and communities.