Lethal interaction: the colliding epidemics of tobacco and tuberculosis.

Tobacco consumption ranks high among the leading health risks and tuberculosis (TB) is a major public health issue in countries where the smoking problem has reached epidemic proportions. Given that both smoking and TB are major health concerns and are widely prevalent in several countries, it is surprising that the association between smoking and TB is still a matter of debate and controversy. Although several studies have evaluated the effect of smoking on TB, the association has been largely overlooked by the TB and public health communities at large. Three recent reviews, including two meta-analyses, have summarized a large body of published literature on the association between smoking and various TB outcomes. These reviews show that there is considerable evidence that tobacco smoking is associated with TB. The evidence is strong for TB disease but less strong for TB infection and mortality. Even if the effect is relatively modest, the population-attributable risk is likely to be substantial due to the widespread nature of tobacco exposure. TB control programs must begin to address tobacco control as a potential preventive intervention. Since tobacco control will have multiple health benefits, it is likely to be a highly cost-effective intervention from a societal perspective.