Key issues in multidrug-resistant tuberculosis

Tuberculosis is responsible for 2 million deaths worldwide and 8 million new cases are reported globally every year. Multidrug-resistant tuberculosis (MDR-TB) is an emerging and difficult public health problem worldwide. In the presence of resistance to key first-line antituberculous agents, treatment with less effective and more toxic second-line agents must be instituted. Consequently, patients remain infectious for a longer period and require prolonged courses of treatment. There may be a role for surgery in selected cases. Care must be taken in terms of isolation procedure and infection control in MDR-TB. Although the diagnosis is made microbiologically, there are certain factors that predispose to the emergence of MDR-TB, notably a history of previous treatment for TB, particularly if that treatment was inadequate or incomplete. Prescription errors made by physicians also contribute, such as adding a single drug to a failing anti-TB regimen. The use of DNA amplification techniques, for example polymerase chain reaction has resulted in the rapid diagnosis of MDR-TB compared with traditional solid culture media. Treatment of MDR-TB usually involves five drugs to which microbiologically, the organism has been shown to demonstrate susceptibility, and one of these drugs should be an injectable agent. There is a need for greater research into developing more effective antituberculous medications and immunotherapy may play an adjunctive role in future management.