An emerging global programme against tuberculosis: agenda for research, including the impact of HIV infection.

During the last 5 years, a worldwide resurgence of tuberculosis has been convincingly documented. Increased numbers of cases have been reported from several industrialized countries and there has been a veritable explosion of tuberculosis in the developing countries of sub-Saharan Africa. The fact that most of this increase is attributable to coexisting infection with the human immunodeficiency virus (HIV) should come as no surprise, because of the role played by cell-mediated immunity in protecting against tuberculosis and the depletion of this immunity by HIV infection. The World Health Organization estimates that there are more than 3 million persons in the world dually infected with HIV and tubercle bacilli. To combat this problem, there needs to be an expansion of programmes designed to identify and treat all patients with tuberculosis, whether HIV infected or not. In addition, the prospects for further advances in basic research, clinical research, epidemiological research and operations research, which have broad application to clinical medicine, are great, and these results will help combat the dual scourges of HIV infection and tuberculosis.