Lesson from surveillance of drug-resistant tuberculosis in Gujarat.

Recent state-wide surveillance of drug-resistant tuberculosis in the state of Gujarat has shown resistance to flouroquinolones (FQ) in 24 per cent cases (19% among new and 25% among previously treated TB cases)1. This increase of drug resistance correlates well with the very widespread use (the broad indications of this class of antimicrobials in lower-respiratory, gastrointestinal, genitourinary etc.) for the treatment of other infections1. The prevalence of fluoroquinolone-resistant tuberculosis is increasing2,3. The patients with resistance to any of quinolones used as antibiotics are likely to develop cross resistance to other or newer quinolones, used for treating tuberculosis. So this is further complicated by inherent cross-resistance and ineffectiveness of such an important group of drugs in treating MDRTB. Multi-drug resistant tuberculosis (MDR-TB), defined as Mycobacterium tuberculosis resistant to isoniazid and rifampin, threatens TB control because of high treatment failure and death rates, and complexities in diagnosis and treatment. MDRTB can be a result of failure of drug sensitive TB treatment with development of resistance (acquired MDR-TB) or direct transmission of an MDR strain (primary MDR). Acquisition can arise from medical error, poor TB control programmes or poor patient adherence to treatment. The extensively drugresistant TB (XDR-TB) is due to resistance of M. tuberculosis to rifampin, isoniazid (definition of MDR-TB) plus resistance to any fluoroquinolone and any of the second-line anti-TB injectable drugs. So XDR-TB is more difficult and expensive to treat than MDR-TB1,4. The resistance to any fluoroquinolone is an essential criterion of XDR-TB. The number of patients with XDR-TB being diagnosed is increasing and the global threat of extensively drug-resistant TB Lesson from surveillance of drug-resistant tuberculosis in Gujarat