97% percent of TB cases worldwide respond to the standard treatment, but the world is not confronting the increasing resistance to drugs to tackle TB.
Multi-drug resistant tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to isoniazid and rifampicin, the two most powerful, first-line or standard anti-TB drugs. Primary reasons why drug resistance occurs are inappropriate treatment, inappropriate or incorrect use of anti-TB drugs, poor patient adherence to treatment, or use of poor quality medicines. In places that already have high levels of MDR- TB there are also significant levels of direct transmission of resistant TB bugs.
MDR-TB is treatable and curable by using second-line drugs. However, second-line treatment options are limited and recommended medicines may not always be available or, if available, are cost prohibitive. Injections and medicines can be required treatment for two years, making adherence a problem. In addition, severe adverse drug reactions can develop, including loss of hearing. Today with all these challenges only 25% of MDR- TB patients are getting diagnosed and treated and only 50% of these patients are treated successfully.