Extensively Drug-Resistant Mycobacterium tuberculosis, India

摘要

To the Editor: India is contrib-uting nearly one third of the world's tuberculosis (TB) cases and has the highest rate of new TB cases (1). Prevalence of multidrug-resistant TB (MDR TB) cases is on the rise in India, and proportions of new cases of MDR TB have been observed to vary from 1.1 to 5.3 in most of the reported studies. The proportion of previously treated patients with MDR TB varied from 8 to 67 (2). Although these studies have been conducted in differ-ent parts of India, they indicate an in-creasing trend of MDR TB cases.MDR TB cases threaten the ef-fectiveness of chemotherapy for both treatment and control of TB and re-quire the use of second-line drugs that are more expensive, toxic, and less effective than fi rst-line anti-TB drugs (3). The Green Light Committee es-tablished by the Stop TB partners (4), which ensures the proper use of sec-ond-line drugs to prevent increasing drug resistance in MDR TB cases in resource-limited countries, encoun-tered resistance to these drugs. This led to the emergence of new termi-nology in relation to drug-resistant TB, i.e., extensively drug-resistant TB (XDR TB). XDR TB is defi ned as TB caused by a Mycobacterium tu-berculosis strain that is resistant to at least rifampin and isoniazid among the fi rst-line anti-TB drugs (MDR TB) in addition to resistance to any . uoroqui-nolones and at least 1 of 3 injectable second-line drugs (5). A recent report describes the current prevalence of XDR TB worldwide (6). Although In-dia has high annual risk for TB cases and increasing prevalence of MDR TB cases, XDR TB has not yet been de-scribed in India