The need for epidemic intelligence.

The past decade has witnessed an unprecedented upturn in tuberculosis morbidity and outbreaks of difficult- to-treat and highly lethal multidrug-resistant tuberculosis. In the early 1990s, a national consensus developed among public health officials to define more comprehensively the problem, and in January 1993, expanded tuberculosis surveillance was implemented nationwide. Carefully selected epidemiologic and case management variables were added to the Report of Verified Case of Tuberculosis form. Information is collected on the health status and treatment of patients, including human immunodeficiency virus status, drug susceptibility test results, and the initial drug regimen. Completion of therapy and use of directly observed therapy are also monitored. The new surveillance system allows a comparison of the quality of care of patients in the public and private sectors. Additional epidemiologic variables include membership in high-risk groups (the homeless, residents of correctional or long-term care facilities, migrant workers, health care workers, and correctional employees) and substance abuse (injecting drug use, non-injecting drug use, and excess alcohol use). The additional information derived from expanded tuberculosis surveillance is crucial to optimal patient management, policy development, resource allocation, as well as program planning, implementation, and evaluation at Federal, State, and local levels.