Rationalizing Use of Fluoroquinolones and Pyrazinamide in the Battle against Multidrug-Resistant Tuberculosis

摘要

Multidrug-resistant tuberculosis (MDR-TB), defined by bacillary resistance to isoniazid and rifampin, is a burgeoning global epidemic that is costly and challenging to tackle. Worldwide, of the ～9 million TB cases in 2011, ～0.3 million (3-4%) had MDR-TB, with about 60% of the cases concentrated in Brazil, China, India, the Russian Federation, and South Africa (1). Approximately 9% of MDR-TB cases were extensively drug-resistant (XDR-TB), which is defined as MDR-TB with additional bacillary resistance to any fluoroquinolone and at least one second-line injectable agent. MDR-TB, and especially XDR-TB, incurs unsustainable management-related costs with chronic pulmonary disability and premature deaths in young adults. In 2011, funding for global TB care and control was about $4.5 billion, of which 0.6 billion was available for MDR-TB. However, approximately $2 billion will probably be required for improving the diagnosis and treatment of MDR-TB by 2015 (1). In South Africa, although drug-resistant TB comprises less than 3% of the total caseload, it consumes ～33% of the 2011 national TB program budget of about $218 million and ～65% of the total TB drug budget (2). Thus, without appropriate management and hence control, drug-resistant TB may drain the resources of national TB programs, thereby offsetting global TB control efforts, and subverting the World Health Organization Stop TB Strategy.