Multi-drug-resistant Tuberculosis

Multi-drug-resistant tuberculosis (MDR-TB) is defined as tuberculosis that is resistant to at least isoniazid (INH) and rifampicin (RMP), the two most powerful first-line treatment anti-TB drugs. Isolates that are multiply resistant to any other combination of anti-TB drugs but not to INH and RMP are not classed as MDR-TB.

MDR-TB develops during treatment of fully sensitive TB when the course of antibiotics is interrupted and the levels of drug in the body are insufficient to kill 100% of bacteria. This can happen for a number of reasons: Patients may feel better and halt their antibiotic course, drug supplies may run out or become scarce, patients may forget to take their medication from time to time or patients do not receive effective therapy. Most tuberculosis therapy consists of short-course chemotherapy which is only curing a small percentage of patients with multi-drug resistant tuberculosis. Delays in second line drugs make multi-drug resistant tuberculosis more difficult to treat. MDR-TB is spread from person to person as readily as drug-sensitive TB and in the same manner. Even with the patent off second line antituberculosis medication the price is still high and therefore a big problem for patients living in poor countries to be treated. With patients not treated, the spread of Tuberculosis would be problematic in poor countries. In order to fully cure infectious diseases, such as Tuberculosis, we need a plan to ensure equal access to health care.