Multiple-drug-resistant tuberculosis

Multiple-drug-resistant tuberculosis (MDR-TB) is a serious global clinical, microbiological and public health problem. The World Health Organization-I nternational Union Against Tuberculosis and Lung Disease Programme on Drug Resistance has reported data from 35 countries demonstrating that MDR-TB is widespread. One-third of countries had levels above 2% in new patients. Dr ug resistance, including MDR-TB,is caused by non-adherence to therapy, inap propriate treatment regimens, drug malabsorption and poor health infrastruc ture needed for the effective delivery of treatment. Individual risk factor s for MDR-TB include prior TB therapy and human immunodeficiency virus infe ction. The key elements of a successful TB programme are the early detectio n of cases, particularly the most infectious and those infected with drug-r esistant strains, combined with successful treatment using standardized reg imens. Countries with poor TB control programmes have a higher prevalence o f MDR-TB: a successful programme limits MDR-TB prevalence. MDR-TB treatment requires individualized therapy based on in vitro drug susceptibility test ing.