Multidrug-resistant tuberculosis: a menace that threatens to destabilize tuberculosis control.

Multidrug-resistant tuberculosis (MDR-TB), caused by Mycobacterium tuberculosis that is resistant to both isoniazid and rifampicin with or without resistance to other drugs, is a phenomenon that is threatening to destabilize global tuberculosis (TB) control. MDR-TB is a worldwide problem, being present virtually in all countries that were surveyed. According to current World Health Organization and the International Union Against Tuberculosis and Lung Disease estimates, the median prevalence of MDR-TB has been 1.1% in newly diagnosed patients. The proportion, however, is considerably higher (median prevalence, 7%) in patients who have previously received anti-TB treatment. While host genetic factors may contribute to the development of MDR-TB, incomplete and inadequate treatment is the most important factor leading to its development, suggesting that it is often a man made tragedy. Efficiently run TB control programs based on a policy of directly observed treatment, short course (DOTS), are essential for preventing the emergence of MDR-TB. The management of MDR-TB is a challenge that should be undertaken by experienced clinicians at centers equipped with reliable laboratory services for mycobacterial cultures and in vitro sensitivity testing as it the requires prolonged use of costly second-line drugs with a significant potential for toxicity. The judicious use of drugs; supervised standardized treatment; focused clinical, radiologic, and bacteriologic follow-up; and surgery at the appropriate juncture are key factors in the successful management of these patients. With newer effective anti-TB drugs still a distant dream, innovative approaches such as DOTS-Plus are showing promise for the management of patients with MDR-TB under program conditions and appear to be a hope for future.