The epidemiology of multidrug-resistant tuberculosis in the United States.

There has been a significant increase in the number of cases of MDR-TB in the United States. Although cases of MDR-TB have been reported from many areas of the country, the majority of the cases are concentrated in large urban areas. MDR-TB is difficult and expensive to treat. CDC has developed a National Action Plan to Combat Multidrug-Resistant Tuberculosis. The main elements of this plan include (1) greater surveillance and epidemiologic studies of drug-resistant TB; (2) initiatives to make the laboratory diagnosis of MDR-TB more rapid, sensitive, and reliable; (3) education of health care professionals about MDR-TB, its prevention, control, and treatment; and (4) measures to facilitate the development of new antituberculous drugs. CDC has published guidelines for the prevention of nosocomial spread of MDR-TB. to prevent the development and spread of MDR-TB, medical practitioners must suspect TB and make the diagnosis as rapidly as possible. Once a patient is diagnosed with TB, the most important step to prevent the development of drug-resistant disease is to ensure that patients take all of their medication. Directly observed therapy is the best way of ensuring this. In addition, more specific interventions, such as the use of incentives to improve compliance in certain situations, may need to be applied to groups in which high rates of drug resistance have been found, such as HIV-positive persons, IDUs, homeless persons, and persons who have been exposed to persons with MDR-TB. Quick and effective public health interventions targeted at these defined groups should help to control the spread of both drug-susceptible and drug-resistant TB.