DRUG-RESISTANT TUBERCULOSIS

Multidrug-resistant tuberculosis (MDRTB) is an iatrogenic disease that is emerging as a major infectious disease problem throughout the worl d. The AIDS pandemic, increased incidence of tuberculosis in populatio ns with easy access to antituberculosis medications, the deterioration of the public health infrastructure, and inadequate training of healt h care providers in the epidemiology of tuberculosis are some of the f actors contributing to the increased incidence of MDRTB. Mortality fro m MDRTB exceeds 80% in persons infected with human immunodeficiency vi rus (HIV) but is also high in patients free of HIV. The management of MDRTB is complicated by the lack of methods for rapid detection of res istant strains of Mycobacterium tuberculosis. The risk of infection am ong close contacts of patients with MDRTB, the probability of the deve lopment of active MDRTB after infection, and the likelihood of cure of MDRTB need to be determined quantitatively. Attributable risk estimat es for factors associated with MDRTB should be calculated for each com munity as part of the strategies to prevent MDRTB. Issues regarding ch emoprophylaxis in newly infected contacts of MDRTB cases remain unansw ered. Basic research on the mechanisms of action of existing antituber culosis drugs may contribute to an understanding of the mechanism of r esistance in M. tuberculosis. There is an urgent need to expand the sc ope of epidemiological, clinical, and laboratory research to address t hese problems.