Acquisition, transmission and amplification of drug-resistant tuberculosis
Multidrug-resistant tuberculosis (MDR-TB) is a man-made problem that constitutes a serious threat to TB management and consumes a considerable amount of resources allocated to TB control. Drugresistant TB only emerges as a result of exposure to anti-TB drugs, and acquisition of resistance in a patient is classically attributed to non-compliance, inappropriate treatment or poor drug quality, while primary resistance results from transmission of drug-resistant strains of Mycobacterium tuberculosis. Herein, we discuss dogmas associated with acquired and primary drug resistance, their origins and how most of these assumptions are changing in the light of recent discoveries. Based on empirical data, we suggest that current control programmes have contributed considerably to the rise of MDR-TB throughout the world and that curbing the MDR-TB epidemic in certain settings may only be possible by the very early detection of drug-resistant strains. The emergence of extensively drug-resistant TB and totally drug-resistant TB in several settings illustrates how continuous use of obviously ineffective control measures creates an ever deadlier disease. Failure to address these issues will threaten the effectiveness of any new drugs and regimens that may be introduced. Copyright © 2011 S. Karger AG, Basel.