In developed countries most patients with tuberculosis are not infectious, can readily access health services, and complete treatment successfully with minimal supervision from a health worker. As a result they make only limited demands on services and pose little public health risk. By contrast, many socially excluded patients are at risk of delayed presentation, poor adherence, and loss to follow-up. A recent persistent outbreak in London including over 220 drug resistant cases and disproportionately affecting homeless people, prisoners, and problem drug users clearly illustrates the urgent need to strengthen tuberculosis control among socially excluded groups.1 Mycobacterium tuberculosis can infect anyone but predominantly affects the poor. Globally, 98% of deaths from tuberculosis are in the poorest countries.2 In rich countries tuberculosis mainly occurs in people born abroad and in socially excluded groups. In London, which accounted for over 40% of all reported cases in the UK in 2004, rates of... (abstract from the article)