Advances in adult pulmonary tuberculosis.

The immune response is able to contain but not eliminate Mycobacterium tuberculosis. Antigens that are specific to M. tuberculosis can identify latent infection accurately even after BCG vaccination. Genes that are required for persistence of the organism have been identified and new drugs are being developed to disrupt their function. This offers the hope of shortened courses of therapy. New drugs are urgently needed for multidrug-resistant tuberculosis, particularly as some areas are reporting a high prevalence of fluoroquinolone resistance. The sputum smear is the standard rapid diagnostic test for pulmonary tuberculosis, but is frequently negative in HIV infection. The yield of smear can be increased by sputum induction and by concentration. Innovative methods of providing directly observed therapy have been devised. Preventive therapy is effective in HIV infection and probably improves survival. However, the duration of benefit of preventive therapy seems to be relatively short-lived. Effective long-term reduction of tuberculosis risk in HIV-infected patients can be achieved with highly active antiretroviral therapy.