The burden of tuberculosis is extraordinarily unequal between countries. Incidence rates range from below 10 per 100 000 population in many mainly high-income countries to greater than 300 per 100 000 population in many other mainly low-income and middle-income countries. 1 It has not always been so. Countries in Europe, North America, and high-income parts of the Asia-Pacific region had high burdens of tuberculosis in the first half of the 20th century, but achieved rapid rates of decline, particularly after World War 2. For example, in Japan, where about 60% of the adult population were screened by chest radiography annually in the 1950s, 2 the annual risk of tuberculosis infection declined by 11% per year between the 1950s and the 1970s, with corresponding declines in disease incidence and mortality. 3 Similarly, there were rapid declines in mortality in Australia during the post-war National Tuberculosis Campaign, which included widespread chest radiography screening for tuberculosis. 4, 5 Hence, the high burden of tuberculosis in some countries today is not an immutable feature of the epidemiology, but rather represents a stage in disease control strategies. Promising new tools to enable active case finding for tuberculosis are available now and others are in development. 6 In settings with a high burden of tuberculosis and endemic transmission, investment7 and activity needs to be focused on community-wide active case finding8 to rapidly reduce the prevalence of infectious cases and, hence, the risk to others of acquiring tuberculosis infection and disease. In many high-burden settings, everyone is at risk of being infected, all the time, everywhere. In these settings it is likely that most cases of active tuberculosis occur due to progression of recently acquired infection, not reactivation of remote past infection (tuberculosis infection acquired many years previously). 9, 10 In research some of us were involved in, we reported that finding most of the cases of active tuberculosis in 60 local communities in the rural province of Ca Mau, Viet Nam, resulted in a 57% reduction in the incidence of tuberculosis over 3 years. 11 Similarly, the case-finding campaigns in Japan, Australia, and other countries in the post-war years also resulted in declines in tuberculosis incidence. None of these interventions were accompanied by vaccination or widespread use of preventive therapy. And in Viet Nam during the period of our study11 and in Australia, there were no major changes in socioeconomic conditions. Since most cases of tuberculosis in high-burden settings are attributable to recently transmitted infection from people with infectious tuberculosis, it follows that people with remotely acquired tuberculosis infection only contribute a small proportion of the incidence of tuberculosis in these settings. Hence,