Tuberculosis (TB) remains a significant global health problem. Approximately a third of the world's populations are infected with Mycobacterium tuberculosis and 95% of cases occur in developing countries. This enormous pool of latently infected individuals is expected to pose a major obstacle for TB control in highly endemic countries and globally. In high income, low TB burden countries, targeted testing of TB case contacts and treatment for latent TB infection (LTBI) is practised as a component of TB control strategies. However, this is not practised in high burden, low-income countries. New evidence from mathematical modelling suggests that, to meet millennium development goals, interventions against M. tuberculosis infection will be required.