Among TB patients, there has been an increase in progressive disease due to the emergence of antimycobacterial drug-resistant strains of Mycobacterium tuberculosis. Failure to identify patients at high risk for MDRTB increases the hazard for both treatment failure and development of resistance to additional therapeutic agents. Efforts to improve survival in patients with MDRTB will depend on improved methods of assessing the risk of acquisition of MDRTB and identifying drug susceptibility patterns in a timely fashion.