Multidrug-resistant tuberculosis (MDR TB)
IntroductionThe significant threat of the global multidrug-resistant tuberculosis (MDR TB) epidemic has been described as a crisis in the World Health Organization's (WHO's) End TB strategy .1 MDR TB is defined as tuberculosis (TB) caused by Mycobacterium tuberculosis isolates that are resistant to at least both rifampicin and isoniazid.2 The WHO's Global tuberculosis report supplement in 2014 estimated that MDR TB accounts for 3.5% (95% confidence interval (CI) 2.2-4.7%) of all new cases of TB and 20.5% (95% CI 13.6-27.5%) of TB cases among individuals previously treated for the disease. 3 There were approximately 480,000 new cases of MDR TB globally in 2013, with an estimated 210,000 deaths attributable to MDR TB. The highest levels of MDR TB are in Eastern European and Asian countries, with more than half the global burden of MDR TB being located in India, China and Russia. 4 Additional cause for concern is the emergence of extensively drug-resistant TB (XDR TB), which is defined as tuberculosis caused by M tuberculosis isolates that are resistant to rifampicin, isoniazid, any ABSTRACT fluoroquinolones and at least one of the second-line injectable drugs (capreomycin, kanamycin and amikacin). Here we provide an overview of the importance of MDR TB, its epidemiology, clinical implications, potential ways of addressing the disease and prospects for new diagnostics and treatment.
EpidemiologyGlobal epidemiology of TB