Abstract
Drug-resistant strains of Mycobacterium tuberculosis pose a major threat to global tuberculosis control. Despite the availability of curative
antituberculosis therapy for nearly half a century, inappropriate and inadequate treatment
of tuberculosis, as well as unchecked transmission of M. tuberculosis, has resulted in alarming levels of drug-resistant tuberculosis. The World Health
Organization (WHO) estimates that there were 600,000 cases of multidrug-resistant
tuberculosis (MDR-TB)/rifampin-resistant (RR) tuberculosis in 2016, defined as strains
that are resistant to at least isoniazid and rifampicin. Globally, WHO estimates that
4.1% of new tuberculosis cases and 19% of retreatment cases have MDR-TB. By the end
of 2016, 123 countries had reported at least one case of extensively drug-resistant
strains, which are MDR-TB strains that have acquired additional resistance to fluoroquinolones
and at least one second-line injectable. It is estimated that only 22% of all MDR-TB
cases are currently receiving therapy. This article reviews the management of MDR/RR-TB
and updates recommendations regarding the use of shorter course regimens and new drugs.
Keywords
tuberculosis - drug-resistant tuberculosis - MDR-TB - XDR-TB - management
